A semiconductor fabrication process for forming a shield-plate electrode or a gate electrode in a trench to have the same conductivity type with each of adjacent p- and n-well regions includes steps for forming a trench in a semiconductor substrate by using a silicon nitride mask, forming an oxide film on the bottom of the trench, and filling a polysilicon film on the oxide film. In a selected region, outside the trench, an impurity of a desired conductivity type is doped by ion implantation to a predetermined depth of the semiconductor substrate. An impurity of the same conductivity type is further doped into the polysilicon film by shallowing the implantation level. In the adjacent region, an impurity of the opposite conductivity type is also doped into the polysilicon film and the semiconductor substrate outside the trench at different implantation levels. Annealing is performed to form a trench filled with p-type polysilicon in the p-well region and a trench filled with n-type polysilicon in the n-well region. The polysilicon in each trench is processed into a shield-plate electrode or a gate electrode.

1. Field of the Invention!
The present invention relates to a semiconductor device having a buried field-shield element isolation structure or a buried gate electrode and a method of fabricating the same.
2. Description of the Related Art!
As the miniaturization of elements advances in semiconductor devices such as LSIs, a field-shield element isolation technology by which a shield-plate electrode is buried in a silicon oxide film has been proposed as an element isolation technology replacing a LOCOS process, in order to decrease the size transformation errors. As field-shield element isolation structures formed by this element isolation technology, a so-called planar structure formed on a silicon substrate and a trench structure in which an element isolation region is formed in a substrate are being studied. An example of an element isolation technology for forming a planar field-shield element isolation structure is disclosed in Japanese Patent Laid-Open No. 6-291181. An example of an element isolation technology for forming a trench field-shield element isolation structure is disclosed in Japanese Patent Laid-Open No. 5-109886.
In a planar field-shield element isolation structure, a shield-gate oxide film and a shield-plate electrode are patterned on a silicon substrate. A cap oxide film and a side-wall protective film are formed to cover the shield-plate electrode.
In a trench field-shield element isolation structure, a shield-plate electrode surrounded by a shield-gate oxide film and a cap oxide film is buried in a trench formed in a silicon substrate.
Note that a semiconductor device in which an element isolation structure is not a field-shield element isolation structure but is formed by burying a trench formed in a silicon substrate with an insulator is disclosed in Japanese Patent Laid-Open No. 1-245540. In this Japanese Patent Laid-Open No. 1-245540, a well is formed by doping an impurity into a silicon substrate in which an insulator is buried in a trench.
In the field-shield element isolation structure disclosed in Japanese Patent Laid-Open No. 6-291181, after the cap oxide film and the side-wall protective film for covering the shield-plate electrode are formed, an impurity is ion-implanted into this field-shield element isolation structure. Consequently, an impurity diffusion layer is formed in the silicon substrate immediately below the shield-gate oxide film, and the ion-implanted impurity distributes in a deep portion of the silicon substrate in an element formation region. Accordingly, the element isolation capability can be improved by the impurity diffusion layer without adversely affecting an element such as a transistor formed in the element formation region.
Also, in the field-shield element isolation structure disclosed in Japanese Patent Laid-Open No. 5-109886, both a shield-plate electrode formed in a p-well region and a shield-plate electrode formed in an n-well region are of an n type. Therefore, in the p-well region, the work function difference between the n-type shield-plate electrode and the p-well diffusion layer below the electrode is large. This decreases the threshold voltage of a parasitic transistor formed in that portion. To avoid this, in the structure disclosed in Japanese Patent Laid-Open No. 5-109886, an enhancement p-type diffusion layer is formed around the trench in the p-well region.
In the above trench structure, however, it is necessary to perform oblique ion implantation or the like to particularly reliably dope a p-type impurity into the side walls of the trench to form the enhancement p-type diffusion layer. This complicates the fabrication process.
On the other hand, Japanese Patent Laid-Open No. 3-290950 discloses that the problem of the work function difference in the p-well region is solved by the use of an n-type shield-plate electrode in the n-well region and a p-type shield plate electrode in the p-well region, and that this obviates the need for enhancement impurity implantation in the p-well region. Unfortunately, the field-shield element isolation structure disclosed in this Japanese Patent Laid-Open No. 3-290950 is not a buried type trench structure but a conventional planar field-shield element isolation structure formed on a substrate.

Semiconductor device and a method of fabricating the same


Provided herein are methods of detecting the presence of a pegylated enzyme, an enzyme-specific antibody (e.g., a neutralizing antibody or of a particular isotype), or a polyethylene glycol (PEG)-specific antibody in a sample, such as a bodily fluid or tissue of a patient. In certain embodiments, the enzyme is phenylalanine ammonia-lyase (PAL), such as Anabaena variabilis (Av) PAL administered to the patient as part of an enzyme substitution therapy for diseases or disorders, such as phenylketonuria (PKU), or cancer therapy.

Phenylalanine ammonia-lyase (PAL) is a non-mammalian enzyme widely distributed in plants (Koukol et al., J Biol Chem 236:2692-2698, 1961; Hanson et al., The Enzymes 7:75-166, 1972; Poppe et al., Curr Org Chem 7:1297-1315, 2003), some fungi (Rao et al., Can J Biochem 45(12):1863-1872, 1967; Abell et al., Methods Enzymol 142:242-253, 1987), and bacteria (Bezanson et al., Can J Microbiol 16:147-151, 1970; Xiang et al., J Biol Chem 277:32505-32509, 2002; Hill et al., Chem Commun 1358-1359, 2003) and can be recombinantly produced in Escherichia coli.
PAL from two cyanobacteria strains, Anabaena variabilis (Av) and Nostoc punctiforme (Np), has been cloned and expressed in bacteria (e.g., Escherichia coli (E. coli), and was shown to display PAL enzyme activity in vitro and in vivo (see, e.g., U.S. Pat. Nos. 7,531,341; 7,534,595; 7,537,923 and 7,560,263). A pegylated recombinant Anabaena variabilis PAL (rAvPAL-PEG) has also been produced, wherein the rAvPAL protein was derivatized by covalent attachment of polyethylene glycol (PEG) to increase its half-life and optimize its pharmacokinetic profile and/or reduce its immunogenicity (Id.). rAvPAL-PEG has been shown to metabolize phenylalanine and is being developed as an enzyme substitution therapy (EST) for patients disorders or diseases associated with elevated levels of phenylalanine, such as PKU, as well as in cancer therapy (Id.).
A concern of administration of enzymes to patients, for example, for PKU EST or cancer therapy, is whether sufficient amounts of the enzyme are available in the body to exert a therapeutic effect in the patient. Moreover, in the case of pegylated enzymes, current methods used to determine the concentration of PEG are relatively insensitive (see, e.g., U.S. Pat. No. 6,596,849), and methods to detect the enzyme itself are complicated by the presence of the PEG. To date, such methods have not determined an effective way to expose the immunogenic epitopes of the therapeutic enzyme (e.g., rAvPAL-PEG) for capture by an immobilized antibody specific for the target therapeutic enzyme, and maximize the number of epitopes recognized by the antibodies, while at the same time minimizing the number of epitopes masked by the PEG molecules.
A further concern of administration of enzymes to a patient, e.g., for PKU EST or cancer therapy, is the possible development of enzyme-specific antibodies in patients, for example, those receiving multiple rounds of therapy. These enzyme-specific antibodies may precipitate potential adverse events and lead to changes in clinical efficacy, including, for example, anaphylactoid-type reactions associated with antibodies of the IgE isotype, changes in pharmacokinetic profile, neutralization of the enzymatic activity, interference with receptor-mediated enzyme uptake, and breaking of tolerance toward self proteins. Current assays to measure the amount of anti-enzyme antibodies in body fluids also suffer from a variety of technical issues, thereby making their interpretation difficult (see Mire-Sluis et al., J. Immunological Methods 289:1-16, 2004).
Given these concerns, as well as the shortcomings of currently available assays, there remains a need for a reliable, sensitive and specific assays to accurately detect or otherwise measure (i) an enzyme (e.g., a rAvPAL) in body fluids, tissues or other samples of a patient receiving the enzyme, e.g., for EST or cancer therapy; (ii) a pegylated enzyme, such as extensively pegylated enzyme (i.e., an enzyme having a sufficient number of PEG molecules attached such that at least some of the immunogenic epitopes of the enzyme are masked by the PEG molecules), (e.g., a rAvPAL-PEG) in bodily fluids, tissues or other samples of patient receiving the enzyme, e.g., for EST or cancer therapy; and/or (iii) enzyme- or PEG-specific antibodies (e.g., anti-rAvPAL, anti-rAvPAL-PEG antibodies, or anti-PEG antibodies) in body fluids, tissues or other samples of patient receiving the enzyme, e.g., for EST or cancer therapy. Such assays could enable assessment of the treatment regimen in a patient receiving the enzyme, e.g., for EST or cancer therapy and facilitate more efficient design of patient therapy.

Assays for detection of phenylalanine ammonia-lyase and antibodies to phenylalanine ammonia-lyase


A rotary electric machine for a vehicle has a stator having a stator winding. The stator winding is made of a plurality of segments. The segments are partly accommodated in a plurality of slots and are arranged to form coil ends groups on both axial sides. The segments are insulated from the stator core by a sheet shaped insulator inserted only along an inner surface of the slot. The segments have bare segments having no insulating layer and covered segments having insulating layer thereon. The bare segments are arranged to surround the covered segments so that the bare segments are not adjacent to the other bare segments in the slots and the coil ends groups.

This application is based on Japanese Patent Application No. 2000-26219 filed on Feb. 3, 2000 the contents of which are incorporated herein by reference.
1. Field of Invention
The present invention relates to a stator of a rotary electric machine mounted on a passenger vehicle, truck or the like. Specifically, the present invention prefers to a stator of an alternator for vehicle.
2. Description of Related Art
Engine room capacity of vehicles in recent years has become smaller as the vehicle has changed to a slanted nose configuration to reduce traveling resistance and to maintain space for passengers. Therefore, the environmental temperature of an alternator has increased. Further, increasing an output of the alternator is required in compliance with increasing of various electric loads, such as a safety control device. As a result, heat generated by the alternator has been increasing. Further, erosion and electric short circuiting are facilitated, when a tire splashes the alternator with water, or when the alternator has water poured on it when the engine room is washed and the like. In cold regions water may contain an anti-freezing agent that is an electrolytic solution. Of course, there is also a requirement to cut costs while maintaining temperature reduction and durability against an environment.
In consideration of the above-mentioned circumstances, the applicant filed JP-B-2927288 and U.S. Pat. No. 5,998,903 that disclose an alternator that has a winding using a plurality of hairpin shaped segments made of an electric conductor. This winding is assembled by inserting the segments into slots of a stator core and joining the segments. In this arrangement, it is possible to reduce resistance of the winding by increasing a space factor of the winding in the slots and to achieve a decrease in temperature and an increase in output. Further, the alternator has insulators having a S-shaped radial cross-section. The S-shaped insulator is disposed between the segments in the slot and between the segments and the slot to eliminate an insulating layer on the segment surface. Therefore, the segments decrease costs.
However, it is difficult to insert the segments wrapped in the S-shaped insulators into the slot. Therefore, the assembling process is complicated. On the other hand, to increase the space factor is not as easy as expected, because it is necessary to prevent the undesirable movement of the insulator between the segments when the segments are inserted after inserting the insulators into the slot.
The present invention addresses these drawbacks by providing an improved stator arrangement.
It is therefore an object of this invention to provide an improved stator of a rotary electric machine for a vehicle.
It is a further object of this invention to provide a stator of a rotary electric machine for a vehicle which is capable of improving the assembly process.
It is another object of this invention to provide a stator of a rotary electric machine for a vehicle which is capable of improving a space factor.
It is a still further object of this invention to provide a stator of a rotary electric machine for a vehicle which is capable of improving durability against the environment.
According to a first aspect of the present invention, the stator of the rotary electric machine for a vehicle comprises a stator core having a plurality of slots, a poly-phase stator winding disposed in the slots and an insulator insulating between the slots and the stator winding. The stator winding comprises a plurality of segments having covered segments, each covered with an insulating layer, and bare segments have no insulating layer. The bare segments are adjacent to only the covered segments in the slots.
Although the bare segment is disposed in the slot, it is possible to insulate the segments in the slots from each other.
The segments may be formed in at least a substantial U-shape. The segments extend from both axial sides of the stator core to form first and second coil ends groups. The first coil ends have turn portions of the U-shaped segments. The second coil ends have a plurality of joining portions joining a pair of ends of the different U-shaped segments extending from the slots spaced apart at a predetermined pitch each other.
The turn portions may have small turn portions surrounding no other turn portions, which are provided by the covered segments. The segment having the small turn portion has a pair of straight portions disposed in the slots that are adjacent to the other straight portions belonging to the other segment having the small turn portion. It is possible to insulate the segments having the small turn portions even if the bare segments are used in the stator winding.
The turn portions may comprise first turn portions which is the smallest, second turn portions surrounding the first turn portions, third turn portions surrounding the second turn portions and forth turn portions surrounding the third turn portions. The covered segments provide the first and third turn portions. The bare segments provide the second and forth turn portions. In this arrangement, the bare segments are not adjacent to each other in both of the slots and the coil ends groups.
The turn portions may have small turn portions provided by the covered segments and large turn portions provided by the bare segments surrounding the small turn portions.
The turn portions may have a pair of the small turn portions provided by the covered segments being arranged side by side in a radial direction of the stator core and the large turn portions provided by the bare segments surrounding them.

Stator arrangement of rotary electric machine for vehicle


The device (10) has a handle assembly (40) and a bone anchor driver assembly (20). The handle assembly (40) has an upper handle portion (50) and a lower handle portion (60). The upper or lower handle portion is rotatable relative to the other handle portion. A bone anchor driver assembly (20) is for rotatably driving a bone anchor (12) into a hole in a bone. The bone anchor driver assembly (20) is fixed to one of either the upper or lower handle portions (50 or 60).

The use of bone screw anchors to hold sutures is a widely accepted practice in shoulder or knee repair and fixation of soft tissue such as ligaments, cartilage and tendons to bone. Ideally the suture anchor is easy to install and provides a solid reliable way to fix the sutures to the bone. The bone has a hard outer cortical shell with a softer underlying region of cancellous bone tissue. The anchor must hold sutures after thousands of repetitive motions tensioning and relaxation until the ligament or tendon repair has time to heal and secure itself to the bone and muscle tissue.
Older style bone anchors had an external eyelet to allow the sutures to be fed through after the screw was driven into the bone. This left the eyelet exposed in the soft muscle tissue.
Later versions of bone anchors have the sutures inserted inside the screw tip well inside the bone. This allows the screw outer end to stay flush with the cortical bone outer surface. The sutures can pass inside in some hollow screws from the tip to the outer surface. A main problem is how to thread the bone anchor into the bone. In some suture anchor systems there is a self-driving feature that has a punch tip that can be malleted into the bone. Once started, the anchor must be rotated to thread it into the bone. The ends of the sutures are often dangling in the way.
Ideally the procedure should insure the bone anchor is easily installed without having the sutures interfering with the anchoring.
The present invention provides a threaded bone anchor that is easy to install wherein the sutures are held securely with the bone anchor, but wherein the ends of the sutures are contained inside the delivery device.

This patent is subject to a terminal disclaimer.

Bone anchor delivery system device with sutures


This invention relates to the creation of a swifter, cleaner, way of moistening envelope flaps to seal them. It represents an improvement over other designs of systems using nozzles in that it adjust for a variety of envelope flap shapes and lengths and depths. It is also an improvement over sponge or wick systems, since no glue build up is created. With a push of a button, a spray of water or sealing fluid, is directed to the flap, after symmetric geared adjustable arms, each arm geared at a pivot between them, are positioned (including a valve on each arm to adjust for a smaller envelope flap). After the envelope is positioned and the button is pushed, a spray of fluid falls upon the flap, directed downward by a number of nozzles on each arm, all connected to the pump and fluid reservoir by flexible tubes and conduits. The spring button returns to position, while drawing fluid up into the small piston pump to be used for another envelope. An electric version would utilize an electric solenoid to activate a piston pump, or use an electric rotary pump.

1. Field of the Invention
In an effort to hasten and streamline, and make easier, the sealing of envelopes with water activated glue flaps, or the application of liquid glue to a non-glued envelope flap; several solutions and styles of mechanisms have been developed. The use of sponges, moistened rolllerballs, wicks, brushes, pads, and spray nozzles, have been proposed to accomplish moistening of envelope flaps.
This present invention is the only envelope mister-sprayer in this field that utilizes an adjustable synchronous mechanism that allows movement of the two arms containing spray nozzles, to move to align on different shaped, different angled symmetric envelope flaps.
2. Description of the Prior Art
This style of mechanism (spray system) is an improvement over existing mechanisms that moisten or seal envelopes, or other material, that use sponges, brushes, roller balls, or other existing systems.
A spray system does not receive a glue build-up from the material to be moistened or sealed. This invention is also much faster, sealing, moistening or gluing an envelope then the existing before mentioned devices.
This invention also uses less energy of the operator, leading to greater productivity.
It adjusts for different lengths and shapes of envelope flaps, which previous sealers do not do.
This invention is cleaner and more sanitary than other style envelope sealers, since bacteria can grow on: the glue build up, in and on the material of: Sponges, brushes, wicks, roller-balls, or any other material contact system. This invention also provides greater sealing, since there is no glue lost, due to a contact system. With a spray system 100% of the glue stays on the envelope, or material to be sprayed. If a liquid adhesive is used, then no loss to build up on a sponge, brush, wick--and no need to replace these items when they wear out. Sponge, wick, brush, or similar systems will need replacing due to wear and glue build-up. This invention does not need to replace parts due to glue build-up or physical contact wear on surface to be glued, or applied to.
This invention adjusts for different shaped envelopes, where as other existing mechanisms do not. And previous relevant inventions only provide for one shape sealing area. Wick, brush, or roller-ball or similar systems, the operator must move the envelope in order to seal. An operator need only place an envelope once, with no movement needed, under the adjustable arms, when utilizing this invention.
This invention loses very little, if any, water or fluid to evaporation to the atmosphere. Where as wick, sponge, brush, or similar systems loose a great deal of water or fluid to the atmosphere; which means more inconvenient replenishing of the fluid reservoir.

Adjustable spray moistener for envelopes


A communication system includes a main control unit controlling a plurality of units, a transmitter for transmitting information between the main control unit and the plurality of units, and an error detector. The error detector can include a modulator and demodulator for modulating or demodulating the transmitted information on the basis of a predetermined rule. The error detector detects a communication error in the transmitted information in accordance with the predetermined rule. Alternatively, the error detector can include a transmitted data creator/analyzer for creating data based on the transmitted information in a state in which the information contains positive data and negative data of the same bit in one frame and analyzes data when the data is received. This error detector detects a communication error in the transmitted information on the basis of the comparison between the positive and negative data. The error detector can also include a space bit addition separator for creating data based on the transmitted information in a state in which a predetermined space bit is added in one frame and separates the space bit when the data is received. This error detector detects a communication error in the transmitted information on the basis of the timing at which the space bit and other bits appear.

1. Field of the Invention
The present invention relates to a unit control oriented communication device for exchanging information between a group of units scattered inside and outside of a system and a main control section for controlling the group of units, and more particularly, to an optical radio communication device which utilizes light (hereinafter referred to as a wireless optical communication device).
2. Description of the Related Art
Conventionally, a copier, a FAX, or a laser beam printer (hereinafter referred to as an LBP) is composed of a main control portion for controlling the entire system and a group of units scattered inside and outside of the system. The group of units are each composed of an output control section comprising a motor, a fan or an actuator, such as a solenoid, and an input control section comprising switches and sensors. In that case, the input/output control sections are respectively controlled mainly through an I/O port of a CPU. Since these input/output control subjects are scattered within the system, they are connected with each other through a wire harness. These input/output control subjects are connected to the main control portion independently from each other (hereinafter referred to as parallel connection). Alternatively, the main control portion serially transfers data to each unit utilizing serial communication. Each unit conducts "serial-parallel conversion", by which the control subjects are connected to the main control portion independently.
An example of the aforementioned parallel connection will be described. In the case of a system shown in FIGS. 31 and 32 which consists of units 406 and 407, the unit 406 serves as a control unit, and the unit 407 serves as a controlled unit (on which a mechanism part, such as a solenoid, is mounted). In this case, a CPU 301 is connected through signal lines directly to respective mechanism portions 401, 402, 403 and 404 in the controlled unit (FIG. 31) to control them. Although an amplification means or the like, such as a transistor, is disposed between the control unit 406 and the controlled unit in an actual circuit configuration, it is omitted in FIGS. 31 and 32 in order to explain the flow of signals.
In another case, the subjects to be controlled are controlled by the CPU 301 through an I/O expansion device 301a, as shown in FIG. 32.
In the above-described methods, the number of signal lines (signal line bundles) increases in proportion to the number of subjects to be controlled, and this makes reduction in the overall size of the system difficult.
That is, as the number of functions of the system increases, the number of input/output control subjects increases, thereby increasing the number of control lines for parallel connection. As a result, production cost increases, and assembly efficiency deteriorates. Hence, the general trend is toward an arrangement of scattered output and input signals into a plurality of physical or functional blocks and transmission of signals by the serial communication.
Serial communication commonly conducted between the main control portion and the group of units is asynchronous serial communication, called UART, or clock synchronizing type serial communication.
In the former type of serial communication, a single frame consists of twelve bits, including a starting bit (1 bit), a data bit, and a stop bit (2 bits). The transmission side outputs a signal representing one frame with a predetermined period. The reception side reads data representing one frame at the same period as the transmission side when it confirms the starting bit.
In the latter type of serial communication, a single frame consists of eight bits. The transmission side outputs a signal representing one frame with a clock signal and a data signal separately through corresponding paths. The reception side reads the status of the data signal at a timing at which a clock signal rises or falls and receives data representing one frame.
However, the above-described conventional methods have the following disadvantages.
(1) In the method of decreasing the number of control lines by conducting serial transfer from the main control portion utilizing serial communication such as UART, a malfunction may occur due to the erroneous transfer caused by noise generated in the system, or the control line may generate radiation noises in the form of an electric field as the serial transfer speed increases.
To overcome this disadvantage, radio transmission of data using light has been considered.
In the field of electric appliances, radio transmission of data using light, so-called remote control, has been conducted. However, such a system is of the unidirectional type (in which data is transmitted only from the transmission device to the reception device). Furthermore, the data transmission speed is such that it cannot catch up with the transmission speed of input/output signals in, for example, a copier, FAX or LBP. Furthermore, when optical transfer is conducted at a relatively high speed in two directions, collision of light or erroneous transmission caused by a disturbance may occur. Also, the existence or non-existence of the reception device cannot be determined at the main control portion. Furthermore, adjustment or checking conducted during the assembly is troublesome, and reduces efficiency.
(2) Although there is no problem in the case of transmission of a signal consisting of one bit, when a signal consisting of a plurality of bits is to be transmitted, all the bits do not change at one time, and transmission of an erroneous signal may thus occur unless data latching is not adjusted.
This problem will be explained in detail with reference to FIG. 33.
In the case shown in FIG. 33, communication is made between the units 406 and 407 through a communication line 405. The communication line 406 may be parallel or serial. This choice is made depending on the transfer speed or the application of the transfer. Although this communication is more advantageous when a plurality of units 407 to be controlled exist, the units 406 and 407 make one-to-one correspondence in this case for the ease of explanation.
A CPU 301 and a transmission means 409 function independently. The CPU 301 sends transmit data to a transmission register 408. The transmission means 409 transfers the content of the transmission register 408 to the unit 407 at predetermined time intervals. A reception means 302 transfers the received data to the individual mechanism sections 401, 402, 403 and 404.
In order to control the unit 407, monitoring of an external status is required. Fetching of externally monitored signals to the CPU 301 through the communication line will be described below with reference to FIG. 34.
A signal from sensors (for example, microswitches or photo-interruptors) 410, 411, 412 and 413 is transferred from a transmission means 303 to a reception means 414. A communication line 416 which connects the transmission means 303 and the reception means 414 may be of the parallel or the serial type. The reception means 414 writes receive data in a reception register 415. The reception register 415 is connected to the CPU 301, and the CPU 301 can read the content thereof at a desired time. That is, new data (which represents the state of the mechanism sections 410, 411, 412 and 413, in this case) is kept stored in the reception register 415.
The transmission register 408 and the reception register 415 will be described in more detail.
FIG. 35 explains the operation of the transmission register 408. The transmission register 408 is required for the CPU 301 and the transmission means 409 being operated independently. The number of bits for the register 408 must be made to coincide with the total number of bits in the destination unit.
In order to conduct mapping between the transmission register 408 and the CPU 301 and thereby assign a certain address of the CPU 301 to the register 408, a write signal 438 is created by decoding an address signal on an address bus 434 by means of a decoder 435 and then by performing an AND operation on the decoded address signal and a write signal 433. The transmit data is transferred to the transmission register 408 synchronously with the write signal 438.
The transmission means 409 latches the content of the transmission register 408 synchronously with a latch signal 439 from a control circuit 437. That is, the transmission means 409 takes in data from the transmission register 408 to its latches corresponding to the bits of the data, e.g., the data in a latch 417 is latched to a latch 425, the data in a latch 418 is latched to a latch 426, and so on. Thereafter, the transmission means 409 conducts transmission operation independently.
Next, the reception register 415 will be described in detail with reference to FIG. 36. Once the reception means 414 receives data from the transmission means 303 of the external unit 407, it outputs a write pulse 452 and latches the data in latches 440 to 447 of the reception register 415. The receive data is read by the CPU 301 from the reception register 415 by means of a signal obtained by decoding an address signal 434 output from the CPU 301 for mapping by a decoder 448 and then by performing an AND operation on the decoded signal and a read signal 449.
Unit control is thus performed through the communication lines 405 and 416.
In a case where data is transmitted from the CPU 301 to the unit 407, the timing of the write signal 438 of the CPU 301 may differ from that of the read-out signal 439 of the unit, as shown in FIG. 37. In that case, data 453 output from the CPU 301 may be latched in the transmission register 408 at a time indicated by data 454 in FIG. 37, and that data may be read in the transmission means 409 at a time indicated by data 455 in FIG. 37. Erroneous transmission of the data does not occur when the data is read in the transmission means 409 at a time other than a transition of the data 454, as in the case of the above-described case. The same thing applies to the case in which data is transmitted to the CPU 301. In the case shown in FIG. 36, data 457 from the reception means 414 is latched in the reception register 415 by the write signal 452 at a time indicated by data 456 in FIG. 38. The latched data 456 is taken in the CPU 301 by the read signal 451 at a time indicated by data 458 in FIG. 39. There is no problem in the case shown in FIG. 38 in which the data is taken in the CPU 301 at a time other than a transition of the data 456.
However, the above-described conventional technique has the following disadvantages.
In the case of the signal whose one bit has a significance, like the signals 401 and 402 shown in FIG. 33 and like the signals 410 and 411 shown in FIG. 34, there is no problem. However, in the case of a significant signal consisting of a plurality of bits, since transition does not occur on the individual bits simultaneously, erroneous transmission may occur.
That is, in a case where the transmission means 409 latches data at the transition of the data 454, as shown in FIG. 39, the transmit data subsequent to a reference number 459 is not guaranteed. Also, in a case where the CPU 301 reads in data at the transition of the data 456, as shown in FIG. 40, data subsequent to 460 is not guaranteed.
In order to avoid this disadvantage, a handshake may be conducted in terms of software or hardware between the CPU 301 and the transmission means 409 or between the CPU 301 and the reception means 414. However, this requires complicated additional circuits and hence increases the production cost of the system.
(3) Parallel connection between a communication device (hereinafter referred to as a master) of the main control portion and the communication device (hereinafter referred to as a slave) of each of the group of units is easily affected by noise or the like. In the case of a series connection, the unit to be controlled independently may affect or be affected by other units.
When the operation of a system is to be controlled utilizing the serial communication for the exchange of information between the central processing unit for executing the main control of the system and the individual units which scatter in the system, the system is conventionally structured in the manner shown in FIG. 45.
In FIG. 45, a master 550 is a main communication device in the central processing unit which controls serial communication. Slaves 551 to 554 are sub-communication devices in the individual units scattered in the system which conduct serial communication and executes information exchange.
In this serial communication, the master and slaves make 1-to-N correspondence. Therefore, exchange of serial data signal is conducted between the main communication device and the individual sub-communication devices which are parallel-connected to the main communication device independently.
Therefore, in the above-described conventional system, the communication lines for the serial data signal are extended over a long distance because of parallel connection, causing malfunction to occur due to the noise generated within the system. Furthermore, its drive ability of the master communication device must be enhanced by providing a drive means in the master communication device. This may increase the production cost.
Furthermore, in the case of a unit that can be detachably mounted by a user, the serial data signal lines may directly receive external noise from the connector of the detachably mounted unit, which leads to breakage of the main control unit. This increases maintenance cost.
Furthermore, in a case where an abnormality occurs in the system, the sub-communication device in a certain unit may be forcibly reset in order to turn off all the actuators or the like connected to that sub-communication device. In another unit, serial communication may be continued for anomaly processing. These necessitate independent parallel connection between the main communication device and the individual sub-communication devices. For example, in a laser beam printer, if paper jam occurs during the paper feeding operation, high-voltage output must be stopped instantaneously in order to protect a light-sensitive drum or the like. However, interruption of the paper feeding logic and restarting of the paper feed after jam has been removed may cause a jam again.

Communication system for detecting a communication error in information transmitted between a plurality of units and a main control unit


A transaction assisting apparatus capable of automatically transacting chain orders. Chain order input unit accepts entry of a chain order and supplies the input chain order to chain order storing unit to be stored therein. Order detecting unit is supplied with an input buy order, and if the buy order placed is for the chain order, it notifies chain order processing unit that the buy order has been placed for the chain order. The chain order processing unit performs a selling/purchasing process with respect to the chain order for which the buy order has been placed. When the selling/purchasing process is completed, deleting unit deletes the corresponding chain order from the chain order storing unit. In the event the price of chained goods has changed, price changing unit changes the price of chain goods correspondingly in an interlocked manner. Display unit selectively displays, on display units, only those chain orders which satisfy certain conditions such as the presence of chained goods.

(1) Field of the Invention
The present invention relates to a transaction assisting apparatus and a recording medium, and more particularly, to a transaction assisting apparatus for assisting transactions wherein sell/buy orders from a plurality of customers are displayed at display units and when a deal for a certain order is offered, an agent places an order for corresponding goods to thereby conduct the deal of goods, and to a computer-readable recording medium storing a program for causing a computer to perform such a transaction assisting process.
(2) Description of the Related Art
In recent years, a variety of transaction assisting apparatus are used with a view to ensuring reliability and swiftness of transactions in goods etc.
FIG. 22 is a block diagram exemplifying a configuration of a transaction assisting system comprising a transaction assisting apparatus for assisting transactions in bonds, terminal units, etc.
In the figure, a transaction assisting apparatus 1 accepts and stores sell and buy orders etc. for bonds, which are input from a terminal unit 2 owned by an agent, performs a predetermined process on the orders, and makes the orders displayed at the terminal unit 2 as well as at display units 3-1 to 3-n installed at customers' side.
A telephone 4 installed at the agent's side is connected via a leased line (hot line) 6 to customers' telephones 5-1 to 5-n.
Let it be assumed that, in this transaction assisting system, a customer A, for example, has requested, using the telephone 5-1, a sell order for bonds with the circular issue (a sort of serial number) "183" to the agent having the telephone 4.
On receiving the request, the agent operates the terminal unit 2 to input the sell order for "183". The transaction assisting apparatus 1 detects the input of the sell order for the bonds "183", stores the input sell order in a storage device therein, and displays the sell order at the agent's terminal unit 2 as well as at the display units 3-1 to 3-n.
FIG. 23 shows an example of a screen displayed in this case at the terminal unit 2 and the display units 3-1 to 3-n. In the illustrated example, sell and buy orders for the bonds "183" are shown in list form. Also, in the screen shown in the figure, sell orders and buy orders are shown in left- and right-hand regions of the list, respectively. "ORDER NO." is a number assigned so as to specify each sell or buy order, and "RATE" indicates the yield of the bond concerned. "AMOUNT" indicates an amount ordered, and "1 BILLION" means one billion yen. The display screen as shown in the figure is called board screen.
In the illustrated example, only one order is shown, but in cases where there are a plurality of orders, sell orders and buy orders are respectively shown in order of rate such that the order with the highest rate (hereinafter referred to as best rate) is listed at top.
If, looking at the display screen, a customer B, for example, puts in a buy order for "183" with the agent by using the telephone 5-2, the agent enters the requested buy order through the terminal unit 2. Consequently, the transaction assisting apparatus 1 performs a contracting process (process executed when a deal is to be closed) with respect to the sell order for "183".
As a result, the deal for "183" is conducted, whereupon the transaction assisting apparatus 1 deletes the sell order for "183" from the storage device and also deletes the display item corresponding to the sell order for "183" from the display screens of the terminal unit 2 and the display units 3-1 to 3-n. If there are other sell orders remaining, display items corresponding thereto are appropriately rearranged according to rates.
The use of the aforementioned transaction assisting apparatus 1 permits reliable and speedy transactions.
In the dealing business, a so-called chain deal is conducted in which one purchases somebody else's goods on condition that he or she sells his/her own goods.
In the case of bonds, for example, chain deal is conducted in such a manner that one purchases somebody else's "200" bonds if a buy order is offered for his/her "183" bonds, or conversely, one sells his/her "183" bonds if a sell order for "200" bonds is offered by somebody else.
Let us consider the case where such chain deal is conducted with the use of the transaction assisting system shown in FIG. 22. If a customer puts in the chain order as mentioned above, for example, the agent enters a sell order for "183" through the terminal unit 2, whereupon the sell order for "183" is displayed at the terminal unit 2 and the display units 3-1 to 3-n.
This chain order is a sell order premised on the presence of a chained order (in this example, "200") on which the chain order chains, and accordingly, the agent must always make sure whether there is a sell order for "200", which is a chained order, and must immediately suspend the sell order for "183" when there is no chained order present.
Thus, when such a chain order is accepted, it is necessary for the agent to always direct his or her attention to chained orders, making the work complicated.
Also, when a buy order is offered for the chain order "183", a buy order for the chained order "200" must be placed immediately in a manner interlocked with such a buy order, which increases the burden imposed on the agent.
Further, in cases where chain orders are chained (for example, the above order for "200" also is a chain order which chains on "201"), the aforementioned operation needs to be repeatedly performed, which often makes it difficult to carry out the process reliably and speedily.
In the transactions in used cars, real estate, etc., so-called replacement deal is a customary practice wherein one purchases somebody else's goods or real estate on condition that a buy order is offered for his or her goods or real estate, or conversely, one sells his/her goods or real estate on condition that a sell order for goods or real estate is offered by somebody else. Problems similar to those described above also arise in this kind of transactions.
Further, in the case of transactions in used cars, real estate, etc., a person who has to pay taxes changes from one to another at the time when the ownership and thus the title are transferred. Accordingly, if the previous owner has paid taxes extra, it is necessary that the overpayment be refunded and also that the deficit be collected from the current owner, thus requiring complicated procedures.

Transaction assisting apparatus and recording medium


A facility diagnosis device includes: a process data acquirer that acquires process data indicating a state of a process executed in a plant; a production data acquirer that acquires production data indicating a production state in the plant; a state information generator that generates state information for estimating an operation state of a facility operating in the process based on the acquired process data or the acquired production data, or the process data and the production data; and a determiner that determines the operation state of the facility based on the acquired process data or the generated state information and the acquired production data.

Conventionally, in a plant, a factory, and so on, process control is performed using various kinds of process data in industrial process. For example, process data measured from industrial process such as pressure, temperature, flow rate, and so on are used for the process control. The industrial process includes various types of facilities such as pumps, motors, compressors, and so on, and the industrial process is operated by controlling various process values by opening and closing valves, operating control of facilities, and so on. Failure of various types of facilities included in the industrial process is diagnosed by a diagnosis device. The diagnosis device measures vibrations, temperature, noise, or the like of the facility using various types of sensors, and the diagnosis device analyzes the operation state of the facility on the basis of the measurement result to diagnose the facility.
The diagnosis devices are roughly classified into an online diagnosis system that constantly monitors sensors installed in a facility online and a handy diagnosis device used for patrol inspection by a worker. In the online diagnosis system, a dedicated sensor is attached to a facility, data measured by the sensor is collected by a dedicated device, the data is analyzed with dedicated software, and failure of the facility is displayed on a display on the basis of the diagnosis result to notify the worker. In the online diagnosis system, for example, a vibration diagnosis system, a rod drop diagnosis system, a P-V (Pressure-Volume) analysis system and so on are available. In the facility diagnosis using the handy diagnosis device, a worker patrols devices of diagnosis target, measures data such as vibration using the handy terminal, and diagnoses the facility on the basis of the measured data.
The following patent literature 1 describes a finding method of abnormality data of automatically measuring operation information such as temperature, pressure, output, vibration, pH, electric conductivity, and flow rate relating to devices and facilities, comparing the measured operation information with past operation information, and displaying attention data on a monitor.
Further, the following patent literature 2 describes a monitoring system in which a sensor is attached to a monitoring target facility, and event data is extracted on the basis of the measured time series data to monitor and diagnose the monitoring target facility.

Facility diagnosis device, facility diagnosis method, and facility diagnosis program


An improved device and method for welding battery jar covers onto battery jars with the battery elements and terminal posts in position in the jar wherein said improvement includes means for pressing the molten bead, created between the battery jar and the battery cover during welding, flat against the cover and the jar until said molten bead solidifies.

The present invention relates to an improved device and method for welding plastic battery jar covers onto plastic battery jars. Specifically, this invention relates to means for pressing the molten bead, created between the battery jar and the battery cover during welding, flat against the cover and the jar interface until said molten bead solidifies.
In U.S. Pat. No. 4,352,977 entitled "Welding Apparatus and Method," an apparatus and method for welding battery covers onto battery jars are disclosed. Said Patent, the disclosures of which are incorporated herein by reference, discloses and claims an apparatus which comprises a main frame, a work zone having loading, welding and unloading stations, means for moving containers to be welded successively from said loading station to said welding station and from said welding station to said unloading station, welding means for positioning and controlling the relationship between the cover and the jar during welding and for forming a welded joint wherein said welding means includes a heating assembly and a clamping assembly, drive means for operating the apparatus and contact means for activating the drive means in a predetermined sequence.
While the apparatus and method disclosed in U.S. Pat. No. 4,352,977 performs satisfactorily, it has been found that when a thermoplastic hot-plate weld is accomplished using said apparatus and method, the melting process causes molten material to form a bead on each side of the interface between the cover and the jar. Under present practices, the outer bead must be cut off or trimmed after the weld has been made and the plastic solidified so that the battery cell will fit into a steel container or tray with other battery cells. It is believed that the cutting or trimming process can open up small weld line imperfections which can result in microscopic leak paths which permit electrolytes (sulfuric acid) to escape the cell causing corrosion problems as well as contributing to the short-circuiting of the battery.


An estimator structure include a nonlinear modified Kalman filter for initial estimate and plurality of bias estimators and a parallel bank of Kalman filters for ambiguity resolution and providing final estimates. The estimator structure is useful for real-time computation of ionospheric propagation delay introduced in the navigation signals by dual frequency GPS receivers.

Parameter estimators have been used to generate parameters estimates of parameters estimated from an input. Bias estimators have been used to generate bias esitmates of bias of an input. The parameter estimators and bias estimators are methods having many possible applications. One such application is range determination of the Gobal Positioning System (GPS) generating pseudoranges which are affected by potential bias, ionospheric propagation delays and phase ambiguities producing ranging errors. GPS receivers are used to acquire position on ground, in air or in space based upon the reception of satellite signals transmitted from the GPS satellite constellation. From the GPS satellite transmit antenna, the satellite signals propagate through free space, the ionosphere and the troposphere to the GPS receiver. The GPS constellation consists of 24 satellites operating in twelve-hour orbits at an altitude of 20,183 km and provides visibility of six to eleven satellites at elevations of five degrees or more above the horizon to users located anywhere in the world at any time. The navigation signals from the satellites consist of two rf frequencies, L.sub.1 at 1575.42 MHz and L.sub.2 at 1227.6 MHz. The L.sub.1 and L.sub.2 signals are modulated by pseudo-random noise (PN) or spread-spectrum (SS) codes and are also modulated with the navigation data-stream at 50 bps carrying various navigation messages. The signals transmitted from different satellites occupy the same rf bandwidth on a Code Division Multiple Accessing (CDMA) basis. In the CDMA techniques, different PN codes are assigned to different satellites and the receiver matches these codes with like reference codes generated in the receiver through cross-correlation technique implemented in Delay Lock Loops (DLLs). Individual DLLs are assigned to different satellites being tracked by the receiver in a parallel approach or a single loop is shared in a time division mode among many satellites in a single channel and less expansive receivers. In addition to making it possible to separate signals from different GPS satellites, the PN codes also make it possible to measure the range to the satellite by measuring the signal propagation delay from the satellite to the GPS receiver by measuring the relative phase of the received signal code phase with the local reference code phase. The accuracy with which such a propagation delay can be measured depends upon the PN code chip rate, the latter directly determining the rf bandwidth of the spread spectrum modulated signal. The measurement accuracy of the propagation delay is equal to a fraction of the PN code chip period, that is, the inverse of the code chip rate. The actual fraction depends upon the various details of receiver implementation and various sources of errors. Each GPS satellite has two codes assigned to it, a distinct C/A code with a chip rate of 1.023 MHz and a P-Code with different offsets and with a chip rate of 10.23 MHz. The L.sub.1 signal is modulated with both the P and C/A codes in phase quadrature and the L.sub.2 signal is modulated with the P-Code.
From the knowledge of signal propagation delay, the range to any satellite can be obtained by multiplying the delay by the velocity of light in free space if the signal is assumed to propagate in free space and all sources of measurement errors are ignored. However, as the GPS signal propagates through the ionosphere and troposphere of the earth, the delay and velocity of light product is termed pseudo-range and will be only approximately equal to the true geometric range. For the purpose of signal propagation delay measurement, the receiver clock must be in synchronization with the GPS satellite clocks controlling the timing of the transmitted GPS signals. The satellite clocks are highly stable atomic standards and any deviation of their timing from the GPS time is monitored and broadcast by the GPS Control Center to users through clock correction navigation messages. Any residual deviation will contribute to error in the pseudorange measurement. If the receiver had GPS time available to it, then by range measurement to at least three satellites, the receiver can determine its position relative to the GPS satellite by triangulation. Also, with the knowledge of GPS satellite positions in a common coordinate system such as the ECEF (Earth-Centered Earth-Fixed) system, the receiver can determine its position anywhere in the world. The positions of satellites are broadcast through ephemeris navigation messages. The absolute navigation accuracy provided by GPS is a function of the accuracy of the pseudorange measurements. The pseudorange measurements are affected by GPS system errors, such as ephemeris errors, clock errors, atmospheric effects of the ionosphere and troposphere and receiver noise.
Ionospheric and tropospheric effects may be significant. The troposphere is the lower part of the atmosphere extending up to an altitude of about 40 km. The propagation delay of the troposphere reaches about 1.9 to 2.5 meters in the zenith direction and increases approximately with the cosecant of the elevation angle. The tropospheric propagation delay is a function of barometric pressure, temperature, humidity, and other weather variables. However, it is rot a function of signal frequency. The tropospheric delay is modeled by mathematical models and can be computed from these models to high accuracy and the modeling error may be a few decimeters if the water vapor measurement is made with sufficient accuracy. The ionosphere ranges between apaproximately 100 km to 1000 km in altitude and behaves as a dispersive medium. The refractive index is a function of frequency, mainly due to the presence of free electrons. The ionospheric propagation delay is proportional to the total electron count which is equal to the integral of the electron density along the propagation path of the signal. Due to the dispersive nature of the medium, the ionosphere introduces a phase delay in the carrier phase and a group delay in the code phase which are equal and opposite in sign, i.e., the carrier phase is advanced while the code phase is delayed. The code delay is also inversely proportional to the square of the carrier frequency of the rf signal to a high approximation and is also a function of the elevation angle via the obliquity factor. In mid-latitude regions, the ionospheric delay can vary between 8 to 30 meters, depending upon the time of day, with possibly much higher values in the equatorial and polar regions. During the periods of high sunspot activity, the delays will be much higher and also exhibit faster variations with time. For single frequency GPS users, the ionospheric corrections are broadcast by GPS messages derived on the basis of mathematical models of the ionosphere. Such models compensate for about half of the delay. Thus, the ionospheric error after corrections is of the order of eight meters, one standard deviation, during a normal solar period. For many precision GPS applications, the ionospheric error is the dominant source of error. This error level is high and dual frequency measurements are used to more accurately estimate the ionospheric propagation delay.
The Standard Dual Frequency (SDF) method makes the ionospheric delay estimate on the basis of code phase measurements alone instead of both the code and carrier phase measurements which have relatively much higher noise variances compared to the carrier phase measurements. As such, the ionospheric delay estimation error using the standard dual frequency method is relatively high especially in the presence of moderate to high ionospheric activity.
Using a standard dual frequency estimation method, range is computed using the dual frequency code measurements providing two equations and two unknown so that and estimates for the ionosphere delays can be computed. Ionospheric delay estimation is conveniently described by a mathematical development. Estimating ionospheric propagation delay from noisy C/A and P/Y code signals, and the L1 and L2 carrier phase measurements may be formulated in terms of the following range equations. ##EQU1##
Range .rho. is the geometric distance between the GPS satellite transmitter and the GPS receiver, plus non-dispersive contributions such as tropospheric refraction and clock drift. The I/f.sup.2 terms represent ionospheric propagation delays where I is proportional to the total electron count of the ionosphere and where f.sub.1 and f.sub.2 are the frequencies having respective wavelengths of .lambda..sub.1 and .lambda..sub.2 for the L.sub.1 and L.sub.2 signals. The range .rho. comprises the delay of free space and the delay of troposphere. From the R.sub.1 and R.sub.2 range equations, range .rho. can be determined. However, such determination does not include the reduction of bias nor the resolution of ambiguities. The terms v.sub.R.sbsb.i and v.sub..phi..sbsb.i for i=1,2 represent receiver noise as manifested in code and cumulative carrier phase measurements respectively, and N.sub.1 and N.sub.2 are the integer ambiguities in the carrier phase measurements.
The range equations may be rewritten as observation equations using an ionospheric delay equation and a coefficient equation.

Kalman filter ionospheric delay estimator


This invention is related to a knock down frame attachment system. The knock down frame attachment system includes a seating portion, a pair of side panels and a plurality of sets of mounting brackets. A set includes both a left and a right mounting bracket. A set of brackets are coupled to each side of the seating portion and to both side panels. Thus, two sets of brackets are required to attach a side panel to the seating portion.

This invention relates to a furniture frame attachment system for furniture, and more particularly to a knock down frame attachment system that allows a furniture frame to be easily disassembled for transportation.
Typical furniture in the industry generally is provided to the consumer in two forms, assembled and disassembled. Fully assembled furniture has become increasingly expensive to produce due to the trend of companies manufacturing the furniture overseas and shipping to other destinations for sale. While rigid attachment and full assembly are necessary for stability during use, they greatly affect the size and the shape of the furniture items during shipment. Disassembled furniture is also available and has a number of advantages including a decreased number of furniture components and decreased shipping costs, as disassembled furniture may be packed more densely as compared with assembled furniture. However, disassembled furniture comes with the drawback that an unsophisticated consumer may have difficulty with the assembly. Additionally, knock down furniture frames may be manufactured overseas. These frames may then be shipped to an assembler or finisher, who assembles the frames and performs any needed finish work on the furniture. Again, the knock down frame provides lower shipping costs. However, any provided knock down frames must supply the necessary support and rigidity to the final furniture piece.
Thus, there remains a need for a system that allows for quick and easy assembly and disassembly of furniture items. More specifically, there is a need in the furniture industry for a system that allows furniture items to be easily disassembled for shipment to decrease the shipping destination costs.


The object of the present invention is to provide a method of manufacturing high permittivity gate dielectrics for a device such as an MOSFET. A HfSiO film is formed by sputtering a Hf metal film on a SiO2 film (or a SiON film) on a Si wafer. A TiO2 film is formed by sputtering a Ti metal film on the HfSiO film and subjecting the Ti metal film to a thermal oxidation treatment. A TiN metal film is deposited on the TiO2 film. The series of treatments are performed continuously, without exposing the films and the wafer to atmospheric air. The resultant TiN/TiO2/HfSiO/SiO2/Si structure satisfies the conditions: EOT<1.0 nm, low leakage current, and hysteresis <20 mV.

1. Field of the Invention
The present invention relates to a method for forming stacked films by stacking high permittivity gate dielectrics each having different relative permittivity constants, and for depositing a metal electrode material film on the stacked films, in manufacture of a metal oxide semiconductor field effect transistor (MOSFET). In particular, the present invention relates to a method for causing the Equivalent Oxide Thickness (EOT) of the MOSFET to be equal to or smaller than 1.0 nm.
2. Related Background Art
In manufacture of the MOSFET, today, the MOSFET is manufactured in combination where a silicon dioxide (SiO2) film is used as the gate dielectrics thereof, and polysilicon is used as the gate electrode thereof. In order to improve the performance of an integrated circuit, the design rule thereof has been reduced gradually. Being accompanied with this, thinning of the gate dielectrics is required. However, there is limitation in thinning of the gate dielectrics using the silicon dioxide (SiO2) film. In other words, thinning beyond the limit results in increase of leakage current beyond the tolerance level.
Therefore, today, application of gate dielectrics having a relative permittivity constant larger than that of the silicon dioxide (SiO2) film is considered. The gate dielectrics is referred to as high permittivity gate dielectrics. When the high permittivity gate dielectrics is used as the gate dielectrics, the gate electrode also have to be changed into a metal electrode. It is because of the two reasons described below. A first reason is in that polysilicon does not match with almost all of high permittivity gate dielectrics. A second reason is in that if polysilicon is used, a depletion region is formed in the interface between the polysilicon and the high permittivity gate dielectrics, thereby, the EOT of the MOSFET becomes larger, resulting in reduction of the capacitance thereof.
Here, the Equivalent Oxide thickness (EOT) will be described. The electric film thickness obtained by means of back calculation by assuming the gate dielectrics material is the silicon dioxide (SiO2) film, without depending on the types of the gate dielectrics, is referred to as the EOT (Equivalent Oxide thickness) of the silicon dioxide (SiO2) film. In other words, when the relative permittivity constant of the dielectrics is denoted as ∈h, the relative permittivity constant of the silicon dioxide (SiO2) film is denoted as ∈o, and the thickness of the dielectrics is denoted as dh, the EOT of the silicon dioxide (SiO2) film, de, is represented by the following formula 1.de=dh×(∈o/∈h)  (1)When a material having a relative permittivity constant ∈h being larger than the relative permittivity constant ∈o of the silicon dioxide (SiO2) film is used as the gate dielectrics, the above-mentioned formula 1 indicates that the EOT of the silicon dioxide (SiO2) film becomes equivalent to the thickness of the silicon dioxide (SiO2) film being thinner than the thickness of the gate dielectrics. In addition, the relative permittivity constant ∈o of the silicon dioxide (SiO2) film is an order of 3.9. Therefore, for example, for a film composed of a high permittivity gate dielectrics material having a relative permittivity constant ∈h of 39, even if the physical film thickness of the high permittivity gate dielectrics material is 15 nm, the EOT (electric film thickness) of the silicon dioxide (SiO2) film becomes 1.5 nm, thereby, the tunnel current thereof can be largely reduced, while the capacitance value of the gate dielectrics being caused to be equivalent to that of a silicon dioxide (SiO2) film having a thickness of 1.5 nm.
Today, HfO2, HfSiO or HfSiON has a high degree of expectation as the high permittivity gate dielectrics. Since the relative permittivity constants of them are an order of 10 to 20, being calculated by using the above-mentioned formula 1, the thickness of the dielectrics becomes an order of 6 to 7. However, since in a practical structure a silicon dioxide (SiO2) film having a thickness of an order of 1 nm, is required between the silicon wafer and the high permittivity gate dielectrics, the film thickness of the Hf-based high permittivity gate dielectrics becomes as thin as an order of 1 to 2 nm, it is difficult to reduce the gate leakage current while satisfying the condition: EOT<1 nm.
Therefore, Honda et al. (JJAP Vol. 43 (2004) p. 1571), formed HfO2 film on a Si wafer, stacked SiO2 having a relative permittivity constant being different from that of the HfO2 film, on the HfO2 film, by means of a pulsed laser deposition method, exposed them to atmospheric air, subsequently, formed a metal electrode film, and then evaluated electric properties of the resultant stacked films. As the result, the hysteresis thereof was 50 to 300 mV, and the EOT thereof was greater than 1 nm (H, Watanabe et al., Jpn. J. Appl. Phys. 45 (2006) 2933).
In this manner research of Metal/High-k gate stack has been energetically advanced as the technology of reducing power consumption and improving the performance of the MOSFET. Although it has been reported that a Hf silicate film has excellent properties as a High-k gate dielectrics material, further reduction of the EOT is required. Since Ti-based oxides have a high relative permittivity constant, improving performance of various kinds of High-k film materials by means of adding Ti has been attempted. Moreover, a phenomenon that forming a TiO2 layer by means of a TiN/HfSiON interfacial reaction reduces the leakage current with little increase of the EOT, has been reported (H. Watanabe et al., Jpn. J. Appl. Phys. 45 (2006) 2933).
In the present invention, the object is to provide an optimum structure of a HfTiSiO film for achieving ultra-thin High-k gate dielectrics satisfying the condition: EOT<1 nm. It is a subject to satisfy the conditions: EOT<1.0 nm, low leakage current, and hysteresis<20 mV, by using a stack structure of Hf-based high permittivity gate dielectrics/Ti-based high permittivity gate dielectrics having a relative permittivity constant being different from that of the Hf-based high permittivity gate dielectrics.

Semiconductor element and manufacturing method thereof


A method for the evaluation of signals of a rangefinder having at least one sensor point involves carrying out measurements cyclically, wherein the rangefinder emits a plurality of measurement points that indicate a distance from the sensor point. The rangefinder measures distances in a plurality of directions, and a horizontal angle is associated with each measurement point. The measurement points are differentiated into useful signals and interfering signals based on the distance. Measurement points with a distance below a first limiting value are identified as interfering signals, and measurement points above the first limiting value are identified as useful signals. Useful signals are associated with a first measurement area when they satisfy a predetermined condition for distance and horizontal angle. The quantity of useful signals in the first measurement area is determined, and a warning signal is emitted when the quantity of useful signals lies below a first threshold value.

The present invention is directed to a method for the evaluation of signals of a rangefinder.
The rangefinder is preferably a laser rangefinder. Laser rangefinders are also known as Lidar systems. Laser rangefinders measure the distance of measurement points from a sensor point of the laser rangefinder. Laser rangefinders which scan a two-dimensional or three-dimensional space are also known as laser scanners.
A self-propelled harvesting machine with a laser scanner is known from EP3300561A1. The laser scanner serves to detect a driving lane for the self-propelled harvesting machine.

Method for the signal evaluation of signals of a rangefinder

CLAAS Selbstfahrende Erntemaschinen GmbH


A porous gas diffusion electrode for membrane fuel cells on an ion-conducting polymer. The electrode contains a finely divided electrocatalyst which is dispersed in a proton-conducting ionomer and has a total porosity of more than 40 to less than 75%. It supplies considerably improved performance data in comparison to known electrodes. The electrode can be produced by using pore-forming materials which are dissolved during the re-protonation of the ion-conducting polymers with sulfuric acid or are decomposed by the action of temperature.

The present invention relates to a porous gas diffusion electrode for membrane fuel cells on an ion-conducting polymer membrane as well as to a method of its production. The use of gas diffusion electrodes for fuel cells has long been state of the art. Several methods for producing these electrodes have been developed for the membrane fuel cell using electrocatalysts based on platinum catalysts or platinum alloy catalysts on conductive carbon carriers.
The control of the contact of the three phases catalyst/electrolyte/gas has proven to be particularly difficult in a solid electrolyte system such as is constituted by a membrane fuel cell with an ion-conducting membrane as electrolyte. Traditional gas diffusion electrodes for use in acidic fuel cells (e.g. the phosphoric-acid fuel cell) are generally produced from a mixture of polytetrafluoroethylene (PTFE) and an electrocatalyst of platinized black which mixture is absorbed on a gas distributor structure. After a tempering procedure this yields a porous, surface-rich and partially hydrophilic, partially hydrophobic structure of the electrode. This enables, during operation in a fuel cell with a liquid electrolyte, good access of the working gases to the electrochemically active centers with simultaneous good wetting by the electrolyte. The entrance of the liquid electrolyte into the depth of the electrode opens up a sufficiently high number of these electrochemically active centers.
A membrane fuel cell consists of, in its essential components, a membrane of an ion-conducting polymer, also designated herein as "ionomer", with gas diffusion electrodes applied on both of its sides as cathode and anode of the fuel cell. The membrane has two large surface areas, or sides and a relatively small thickness. The cathode and anode electrode contain suitable fine electrocatalysts for accelerating the oxidation of the fuel, as a rule hydrogen, on the anode and reduction of the oxygen on the cathode. The polymer membrane forms the electrolyte. The conduction of current through the membrane takes place by the transport of protons.
Platinum is preferably used as the catalytically active component of the electrocatalyst, which platinum can also be alloyed with one or several metals of the groups VB, VIB, VIII and IB of the Periodic Table of Elements. The optimum particle size of the catalytically active alloy particles is in a range of 2 to 10 nm. For use in the electrodes of fuel cells the catalytically active components are employed as carrier catalysts, that is, the metal or alloy particles are deposited on a carrier which can be finely divided, electrically conductive carbon materials such as e.g. furnace black and worked in this form into the electrodes. Alternatively, however, there is also the possibility of bringing the alloy particles directly into the electrode material without carrier.
The access of the electrolyte into the depths of the electrode is not readily possible in a membrane fuel cell. The so-called three-phase zone remains, without special provisions, limited to the range of the contact surfaces between membrane and electrodes.
U.S. Pat. No. 4,876,115 teaches a method of modifying commercial gas diffusion electrodes which are usually used in liquid electrolyte systems. These electrodes contain as binder hydrophobic particles of polymeric PTFE, which simultaneously regulates the wetting properties of the electrode and stabilizes the porosity of the electrode layer. In order to improve the contact of the three phases; i.e. catalyst/electrolyte/gas, the prefabricated electrode is impregnated with a solution of a proton-conducting material by spraying and then bringing into contact the sprayed side with the proton-conducting membrane. The porosity of the electrode is formed only by the intermediary spaces between the particles of the electrocatalyst and of the hydrophobic PTFE.
If the electrode is impregnated with an ionomer as proton-conducting material only approximately 10 .mu.m of the depth of the electrode is reached by the electrolyte as a result of this pretreatment. Therefore, a large part of the electrocatalyst remains electrochemically unused in the electrode, which is generally 100 to 200 .mu.m thick. Performance data similar to that obtainable with conventional electrodes with surface concentrations of 4 mg Pt/cm.sup.2 can be achieved with these electrodes at surface concentrations of 0.35 to 0.5 mg Pt/cm.sup.2. However, the maximum concentration when using carrier catalysts is limited to values of approximately 0.5 mg Pt/cm.sup.2 on account of the electrochemical utilizable layer thickness, which is only about 10 .mu.m thick. A performance increase by raising the surface concentration of catalyst is therefore possible only to a slight extent. This excludes those electrodes from applications which, according to the current state of knowledge, require catalyst concentrations of 4 mg Pt/cm.sup.2 and more, as is necessary e.g. in a direct methanol fuel cell. In order to produce such electrodes with higher, electrochemically utilizable concentrations, carrier-free catalysts must be used.
The production of electrodes for membrane fuel cells by spraying a dispersion of dissolved ionomer, electrocatalyst and PTFE onto the heated membrane is described by S. Escribano et al. (Editions de l'Etcole Polytechnique de Montreal 1995, pp. 135-143). The electrodes are only a few micrometers thick and have pores with pore radii of approximately 50 nm. Thereafter, gas distributor structures are hot pressed onto the electrode layers. Temperatures near the melting point of PTFE (320.degree.-360.degree. C.) are used in that process in order to sinter the PTFE particles. PTFE functions in these electrodes as binder and hydrophobing agent.
According to U.S. Pat. No. 5,211,984 PTFE is eliminated as binder and hydrophobing agent and a non-self-supporting electrode is obtained consisting only of catalyst and ionomer. To this end a suspension of dissolved ionomer and platinized black is applied in a method variant onto a PTFE carrier, dried and the pre-formed electrode is pressed with the PTFE carrier onto a membrane. The PTFE carrier can subsequently be drawn off free of residue. The electrode with a thickness of approximately 10 .mu.m adheres very well to the membrane after the hot pressing procedure.
The electrode produced in the manner shown in the prior art consists of a dense layer of ionomer and electrocatalyst. The electrode layer therefore contains essentially no pores and also no hydrophobic additives. The electrode layer is therefore limited to a maximum thickness of 10 .mu.m. This maximum layer thickness also assures a sufficiently good transport of the oxygen to the catalyst particles by diffusion through the ionomer. A layer thickness of less than 5 .mu.m is preferably striven for. Even these electrodes achieve performance data with surface concentrations of less than 0.35 mg Pt/cm.sup.2 similar to that of conventional electrodes with concentrations of 4 mg Pt/cm.sup.2. However, performance increases can hardly be achieved with these electrodes either when using carrier catalysts since the surface concentration can not be raised on account of the low layer thickness.
Ionomeric polymer membranes can be present in an acidic, proton-conducting H.sup.+ form or, after exchange of the protons by monovalent ions such as e.g. Na.sup.+ and K.sup.+, in a non-acidic Na.sup.+ or K.sup.+ form. The non-acidic form of the polymer membranes is usually more resistant to temperature stresses than its acidic form. The membranes are therefore preferably used in their Na.sup.+ form for the applying of the electrode layers--likewise the ionomer present in solution for the electrode layer. In the last method step of the production of electrodes the polymeric material is transformed by so-called reverse protonation back into the acidic, proton-conducting form. This usually takes place by treating the unit consisting of electrode/membrane/electrode (EME-unit) in sulfuric acid.
According to U.S. Pat. No. 5,211,984 the robustness of the electrode layers can be further improved if the dissolved ionomer is present in a thermoplastic form in the suspension of catalyst and ionomer solution used to produce the electrode layer. The thermoplastic form is obtained by ion exchange of the proton-conducting form of the ionomer with e.g. tetrabutylammonium cations.
U.S. Pat. No. 4,469,579 describes the production of porous electrodes on solid electrolyte membranes for use in sodium chloride electrolysis cells. The electrodes are produced by spraying the membrane with a dispersion of an electrocatalyst in a solution of an ionomer, which dispersion can contain pore-forming materials in order to produce pores for the transport of the gases formed during the electrolysis. The pore-forming materials are dissolved out of the electrodes after removal of the solvent, that is, after drying of the electrodes.
Oxides, hydroxides, nitrates or carbides of various elements with particle sizes between 0.025 mm and 3 mm have been suggested in the prior art as pore-forming materials. Fibrous pore-forming materials with lengths up to 50 mm are preferably used. A preferred pore-forming material is zinc oxide, which is dissolved out of the electrode with sodium hydroxide solution after drying.
The German publication 15 46 701 corresponding to U.S. Pat. No. 3,385,780 discloses a method for the preparation of a porous electrode for fuel cells. According to the method described therein, a finely divided electrocatalyst is mixed with a hydrophobic polymer and a filler for the preparation of a first mixture. A second mixture is than prepared without the electrocatalyst. Both mixtures are than conveyed to a press in two separated sheets and are pressed at a pressure of 350 and 840 bar. Subsequently, the filler is removed so that a unitary porous body is obtained. The fillers that can be used include a thermally heat decomposable material or a material which can be leached out and removed with a strong base. Suitable fillers include ammonium oxalate, ammonium carbonate, silica gel, alumina and calcium carbonate. As hydrophobic polymers, there is mentioned polytetrafluoroethylene as an example. No disclosure is found in this publication of the porosities obtained in the resulting electrodes. Because of the high pressures used, it may be presumed that the electrode material is highly compacted and that the porosity is determined based only on the above mentioned fillers which are used and subsequently are removed in making the electrodes.
European 0 622 861A1 discloses a membrane electrode structure. In order to prepare the electrode, a so called ink is prepared which is formed of a 5% ionomer solution in 50% isopropanol, 25% methanol and 20% water, 1-methoxy, 2-propanol and platinum-C-catalyst (20% by weight platinum on Vulcan black). The ink is then printed on the polymeric membrane with the use of a screen printing procedure. Electrode coating and the membrane are subsequently pressed together at 127.degree. C. under pressure of 20.7 bar. In the description of this patent application, it is mentioned that the electrode coating should be porous. An average pore diameter of 0.01 to 50 microns, preferably 0.1 to 30 microns and porosity of 10 to 99%, preferably 10 to 60% is described. However, for the person skilled in the art it is clear these porosities can not be realistically achieved with the described preparation procedures. This is equally true for the pore diameter as well as for the porosity.
The performance data of fuel cells is highly dependent on the oxidizing agent selected. Maximum values are obtained when pure oxygen is used. When air is used the performance data distinctly drops.
Polymer electrolyte fuel cells, which constitute the subject matter of this invention, are intended to be primarily used as current suppliers in vehicles. Therefore, the goal is to operate the fuel cells with air. The creation of successful gas diffusion electrodes for operation in air is therefore of decisive importance for the successful use of fuel cells as the energy source in motor vehicles.
An object of the present invention is to improve gas diffusion electrodes for membrane fuel cells in respect of performance data during operation in air.
A further object of the present invention is to improve operation of gas diffusion electrodes by controlling the interplay of the three phases of catalyst/electrolyte/gas.
A still further object of the present invention is to create a method of producing these improved gas diffusion electrodes.

Gas diffusion electrode for membrane fuel cells and method of its production


A system and method for providing operational feedback of systems using electronic tags such as radio frequency identification (RFID) tags for inventory monitoring, including reference tags, that provide feedback to check if all inventory items have been identified. In one configuration, the RFID reader actuates by a single trigger pull, with the reader continuing to read multiple RFID tags in the read zone until a terminating event occurs.

The field of the present disclosure relates to operating methods and techniques for systems employing electronic identification tags such as radio frequency identification (RFID) tags. In particular, methods and apparatus are described herein for improving and facilitating operation of electronic tag and RFID reading systems.
RFID interrogators use electromagnetic energy as a medium through which to send information. Typically, RFID tags are affixed to various articles for allowing identification of items in a sales transaction or tracking movement of the articles through a warehouse location. In a typical RFID tag system, the components forming the interrogator are a receiver, a transmitter, an antenna, a microprocessor and memory. Through the use of the interrogator, RFID tags are enabled to receive, store and transmit article-identifying data without manual handling operations. RFID tags may be read-only or read-write. Passive RFID tags may be implemented without an internal power source and draw their power from the radio frequency (RF) energy transmitted from the reader. Active RFID tags may include a power source such as a battery. RFID tags may be low or high frequency depending on the applications.
Existing RFID systems do not provide feedback to the user of an RFID reader to indicate whether or not the user completely covered an inventory area. The present inventors have recognized that it may be advantageous for a user to know what the RFID antenna coverage area is, so that the user may completely cover an inventory area. For applications with multiple inventory items such as in a warehouse, existing RFID systems provide no indication whether all swept RFID tags have been read.
The present inventors have recognized the desirability of providing methods and systems in the operation of RFID reading systems for improving operational efficiency and inventory monitoring performance.

Method and system for inventory monitoring


The invention relates to a device for depositing especially crystalline layers on especially crystalline substrates, said device comprising a process chamber which is arranged in a reactor housing and comprises a substrate holder for receiving at least one substrate. A gas-admittance body is arranged opposite the substrate holder, said body comprising a gas-leak surface facing the substrate holder and provided with a plurality of essentially evenly distributed outlets for process gases to be introduced into the process chamber. In order to improve the observation of the surface temperature, the inventive device is provided with a plurality of sensors arranged to the rear of the outlets and respectively aligned with an associated outlet.

A device of this type is already known from EP 0 687 749 B1. This document describes an MOCVD reactor comprising a rotationally symmetrical process chamber, the floor of which forms a substrate holder. The ceiling of the process chamber, opposite the floor, has a multiplicity of narrow, closely adjacent outlet openings, the outlet openings being connected there in an alternating manner to two different rear chambers. Gases that are different from each other are introduced into these chambers and then flow into the process chamber through the outlet openings.
MOCVD reactors comprising a gas inlet member similar to a shower head are additionally also already known from DE 10136858 A1 and DE 10217806 A1.
U.S. Pat. No. 6,500,266 B1 describes a reactor in which a separate cover is provided for the temperature calibration.
With the aforementioned devices, it is possible to deposit crystalline layers, in particular of a III-V material, on substrates disposed on the substrate holder. In order to measure the temperature profile on the substrate holder, which is heated from the rear, it is known to measure its temperature pyrometrically, for example by means of photodiodes. For this purpose, these photodiodes may be disposed vertically above the floor within the gas inlet member. These sensors are then removed again for the operating process, that is the depositing of layers.
It is also known to measure the temperature of the surface of the substrate holder or of the substrates during the growing process.
It is an object of the invention to develop a device of the generic type with a view to better observation of the surface temperature of the substrate holder.

CVD reactor comprising a photodiode array


The present invention relates to apparatus and methods that reliably detect defects on centerplane connectors. The apparatus and methods include a visual inspection system. The visual inspection system includes a control box, an inspection cart, a camera jig, and a vision system. The vision system has a light emitting diode (LED) lighting system that provides the necessary lighting for the camera on the vision system. The vision system is mounted to the camera jig via a spring-loaded mechanism. The camera jig has dimensions similar to a daughter card that is used with the centerplane connectors. The camera jig also includes a motor and worm gear assembly that raise and/or lower the camera's view of the centerplane connectors. The control box is mounted to the inspection cart so that an operator can use it to control the up/down movements of the vision system. A timer/relay may be build into the control box to allow controlled/fixed movements of the vision system. The camera is connected to a high resolution color monitor and/or an optional flat screen color monitor. A computer workstation can be used to video capture the camera's image and can be used to send this image to an e-mail alias/webpage or print out a hard copy.

1. Field of the Invention
The present invention relates to connectors for connecting circuit boards. More particularly, the present invention relates to apparatus and methods for detecting defects of connectors on circuit boards.
Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever.
Sun, Sun Microsystems, the Sun logo, Sun Fire, 3800-6800 Midframe, Ultra, Solaris, and all Java-based trademarks and logos are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. The VHDM trademark is used under license and is a trademark of Teradyne, Inc. in the United States and other countries. All SPARC trademarks are used under license and are trademarks of SPARC International, Inc. in the United States and other countries. Products bearing SPARC trademarks are based upon an architecture developed by Sun Microsystems, Inc.
2. Description of Related Art
Most computer systems include a connection structure for connecting printed circuit boards of the computer system together (e.g., central process unit boards, memory boards, etc.). One such connection structure includes a circuit board that serves as a centerplane. The centerplane (or backplane) has a set of centerplane connectors mounted to the centerplane. For such structure, the computer system also includes another circuit board called a daughter card that has card connectors that mate with the centerplane connectors. That is, the centerplane connectors and the card connectors typically include corresponding sets of contacts, respectively. For example, pins and pin-receiving sockets, which are configured to make electrical contact with each other when the centerplane connectors and the card connectors mate.
Installation of a daughter card into a computer system typically involves a user sliding the daughter card into an opening of a card cage of the connection structure. The centerplane typically resides the rear end of the card cage, or in the middle of the card cage if the card cage is configured to receive daughter cards through both ends. As the daughter card slides within the card cage, card connectors along the edge of the daughter card eventually engage centerplane connectors mounted to the centerplane at the rear or in the middle of the card cage. After the card connectors make electrical contact with the centerplane connectors, the user continues to slide the daughter card further into the card cage until the daughter card moves into a fully-seated position within the card cage. The user can repeat this installation process for other daughter cards as well.
To avoid damage to the daughter card and/or the centerplane, a detailed inspection of the centerplane connectors is required before inserting the card connectors into the centerplane connectors. The centerplane connectors should be inspected for mechanical defects such as bent and/or damaged pins on the centerplane connectors. The detected defects need to be remedied prior to insertion of the daughter card or the defects may spread into other connectors and on to the daughter card. However, because of the larger number of relatively small contacts on each of the centerplane connectors (e.g., a central processing unit (CPU) connector may have 840 pins, a repeater board (RP) may have 1400 pins, an input/output (I/O) may have 560 pins), the prior arts were unable to reliably spot damages on the centerplane connectors.
Accordingly, there is a need to provide apparatus and methods that reliably detect defects on the centerplane connectors. That is, it would be desirable to provide an inspection system that can reliably spot damages on centerplane connectors having a larger number of relatively small contacts.

Methods and apparatus for inspecting centerplane connectors


A wireless communication system is described that generates FDFR transmissions with any number of transmit and receive antennas through flat-fading channels and frequency- or time-selective channels. In particular, the system utilizes layer-specific linear complex-field (LCF) coding with a circular form of layered space-time (ST) multiplexing to achieve FDFR wireless communications with any number of transmit and receive antennas through flat-fading and frequency- or time-selective channels. Additionally, the described techniques provide flexibility for desirable tradeoffs among performance, rate, and complexity.

Rapid increase of cellular service subscribers and wireless applications has stimulated research efforts in developing wireless communication systems that support reliable high rate transmissions over wireless channels. A major challenge in designing high-performance, high-rate systems is the mitigation of fading propagation effects within the prescribed bandwidth and power limitations. In order to mitigate deleterious effects fading has on system performance, transmitters and receivers that exploit available diversity have been developed. To this end, multi-input multi-output (MIMO) wireless links are particularly attractive when compared to single-input single-output wireless links. Existing MIMO designs utilizing multiple (Nt) transmit antennas and multiple (Nr) receive antennas aim primarily at achieving either high performance or high rate.
MIMO systems that achieve high performance by utilizing the available space-diversity. Space-time (ST) orthogonal designs (OD), linear constellation preceding (LCP) ST codes, and ST trellis codes are examples of performance driven designs. ST-OD codes can achieve full diversity (FD), i.e. the product of transmit and receive antennas, with linear decoding complexity. ST-OD systems with (Nt, Nr)=(2, 1) antennas can achieve transmission rates up to one symbol per channel use (pcu). However, relative to full rate (FR) MIMO designs capable of Nt symbols pcu, other ST-OD codes incur significant rate loss. For example, ST-OD systems with Nt>2 have transmissions rates less than 0.75 symbols pcu. ST-TC schemes can offer better transmission rates, but are complex to decode and lack closed-form construction while their design complexity increases exponentially with Nt. In addition, high rate high performance ST-TC often require long size block resulting in long decoding delays.
MIMO systems designed to achieve high rate utilize the capacity of MIMO fading channels. Bell Laboratories layered space time architecture (BLAST)-type architectures and linear dispersion (LD) codes are examples of rate driven designs. LD designs offer no diversity guarantees. LD designs including diversity constraints are imposed require a search over a high dimensional space that becomes prohibitively complex as Nt and the constellation size increase. However, layered ST multiplexers have complementary strengths and limitations. For example vertical-BLAST (V-BLAST) offers FR, i.e. Nt symbols pcu, but relies on single-input single-output (SISO) error control coding per layer to offer performance guarantees. On the other hand, Diagonal-BLAST (D-BLAST) systems utilize space diversity but have rate improvements that come at the price of increasing decoding delays. Nevertheless, V-BLAST and D-BLAST can afford reasonable complexity decoding and facilitate SISO codes in MIMO systems. However, the rate efficiency of V-BLAST and D-BLAST schemes is offset by the bandwidth consuming SISO codes required to gain diversity. In other words, both high performance and high rate ST codes do not take full advantage of the diversity and capacity provided by MIMO channels. Furthermore, conventional schemes are not flexible to strike desirable tradeoffs among performance, rate, and complexity.

Full-diversity, full-rate complex-field space-time coding for wireless communication