A method of programming a tire pressure monitor sensor utilizes a programming tool that transmits LF data frames to the TPMS sensor that includes a cyclic redundancy check (CRC) code with each data frame. The starting point for the subsequent data frame will then start with the CRC code received from the previous frame and will end with a new CRC code. Accordingly, the CRC code received from the previous frame will be used to ensure that the next data frame matches that CRC code as the starting point for that frame. This will ensure that the data frames cannot get out of sequence and will allow the ability to quickly identify where the data frames have gone out of sync and allow the programming tool to quickly react.

This section provides background information related to the present disclosure which is not necessarily prior art.
Tire pressure monitoring systems have been developed, including a tire pressure monitor sensor (TPMS) that is mounted to each wheel for sending signals to a central receiving unit aboard a vehicle for providing information regarding the tire pressure and temperature. Each of the tire pressure monitor sensors includes a respective radio frequency (RF) transmitter that transmits an RF signal in response to the receipt of an LF (low frequency) activation signal. The RF signal includes both an identifier code and an indicator of tire pressure and temperature. Each TPMS is manufactured with a unique identification number which is sent as part of the radio transmission. The IDs of the TPMS's fitted to the vehicle are given to the vehicle so that the vehicle can discriminate between transmissions from its own TPMS's and ones from another vehicle.
During the manufacture of a vehicle, and when the vehicle tires are rotated, the sensor identification and location needs to be stored in the vehicle receiving unit. In order to store the tire pressure monitor sensor identification, the tire pressure monitor sensors need to be activated using an LF antenna coil providing an activate signal. Upon proper activation, the TPMS then transmits its identification as well as the tire pressure. Generally, the transmission from the TPMS is in the form of a radio transmission. Any tool used to obtain the TPMS ID has to make sure that the ID obtained is in fact the correct one, and not from a TPMS transmitting nearby.
Some aftermarket TPMS sensors are programmable sensors that are programmed by receiving low frequency data frames at approximately 125 kH. For tire pressure monitor sensors, it is important to ensure that the program is transferred accurately from the programming tool to the programmable sensor. Accordingly, a system, such as a cyclic redundancy check (CRC), is employed so that the receiving TPMS sensor can validate the data received from the programming tool.
A CRC is a form of integrity checksum. It is a method for determining errors in the received data by grouping the bytes of data into a block and calculating a cyclic redundancy check (CRC). The CRC is usually appended to the end of the data frame. The receiver of the frame will then perform the same calculation of the data to generate its own CRC and then compare it against the CRC that was transmitted in the frame. By way of example, a transmitted frame including Data 0, Data 1, Data n, Data n+1, and a CRC value would be confirmed by taking the sum of Data 0+Data 1+Data 2+Data 3=CRC. Thus, the system confirms that the calculated sum value of Data 0 through Data 3 is equal to the CRC that was transmitted with the transmitted data frame. This process would be carried out for each transmitted data frame just to confirm full receipt of the data within each transmitted frame. In a typical communications protocol that does not rely upon the acknowledgement of each individual frame transmitted, or the inclusion of a sequence byte in the data (which is a security vulnerability), it is possible that the receiver may fail to receive such a frame and will ultimately fail to program correctly.
For TPMS, it is not advisable to allow anyone to have the ability to reprogram the sensors, and so encryption of the programming process is used and the absence of unencrypted data helps maintain the security of the system. TPMS sensors may run their processing units at low speed in order to preserve battery life, and may also turn off parts of their circuitry that are not needed. For example, it may be that a TPMS sensor cannot both process low frequency (LF) data and transmit UHF at the same time. One method of programming a sensor using LF is to send data in frames, and for the sensor to validate the data, and then signal using UHF to indicate that the frame was received correctly, before the programming tool sends more LF data. This is a fairly slow process, so improved quicker processes are desired.
Another method of programming a sensor using LF is for the sensor to validate the data, and then only to use UHF to signal that it has detected a problem with the data, or that the process has been successfully completed. In a system where data is being transferred to a programmable sensor by LF in a succession of frames which contains a CRC, it takes time for the TPMS sensor to react to faulty data, and to then transmit a UHF frame to request that the LF data is re-sent.
One solution to this problem would be to leave a large time period between LF data frames, so that the TPMS sensor would have time to request re-sending before the next LF frame is sent. However, this would result in an unnecessarily slow programming process in the usual case where the data is transferred without corruption. If a new LF data frame is sent before the TPMS sensor could have requested re-sending the previous frame, then it is important to know that the tool sending the LF data and the receiving TPMS sensor are both in step. For example, it is possible that the tool might not receive the UHF request so that the TPMS sensor could interpret the next new LF data frame as being the re-sent LF frame.
The present disclosure provides a method of programming a tire pressure monitor sensor to solve the above-described problem. In particular, the present disclosure utilizes a programming tool that transmits LF data frames to the TPMS sensor that includes a cyclic redundancy check (CRC) code with each data frame. The starting point for the subsequent data frame will then start with the CRC code received from the previous frame and will end with a new CRC code. Accordingly, the CRC code received from the previous frame will be used to ensure that the next data frame matches that CRC code as the starting point for that frame. This will ensure that the data frames cannot get out of sequence and will allow the ability to quickly identify where the data frames have gone out of sync and allow the programming tool to quickly react.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

Programming method for tire pressure monitor sensors


A heat pump type hot water supplying apparatus includes a hot water reservoir tank (3) and a circulating path (12) for connecting a water intake port (10) formed at the bottom of the hot water reservoir tank (3) and a hot water inlet (11) formed at the upper portion of the hot water reservoir tank (3) to each other. A water circulating pump (13) and a heat exchanging path (14) are disposed on the circulating path (12). A boiling operation is performed for heating the heat exchanging path (14) by a heat pump type heating source, boiling water which has not been heated yet from the water intake port (10) and returning the heated water to the hot water inlet (11). A bypassing path (17) branched from the hot water inlet (11) and connected to the bottom of the hot water reservoir tank (3) is disposed on the circulating path (12). A freeze-proof operation by circulation is performed such that the water circulating pump (13) is driven and the water reserved in the hot water reservoir tank (3) is returned to the hot water reservoir tank (3) via the bypassing path (17).

As shown in FIG. 5, a heat pump type hot water supplying apparatus is generally provided with a tank unit 52 including a hot water reservoir tank 51 and a heat pump unit 54 including a water heat exchanger 53. A water intake port 55 formed at the bottom of the hot water reservoir tank 51 and a hot water inlet 56 formed at the upper portion of the hot water reservoir tank 51 are connected to each other through a circulating path 57, on which a water circulating pump 58 and a heat exchanging path 59 are disposed. In this case, the water heat exchanger 53 constitutes the heat exchanging path 59, which is heated by a heat pump type heating source. Specifically, a boiling operation is performed such that the water circulating pump 58 is driven, water which has not been heated yet is boiled by the heat exchanging path 59, and then, the heated water is returned to the hot water inlet 56.
Here, the heat pump unit 54 includes a compressor, an expansion valve and an evaporator in addition to the above-described water heat exchanger 53, although not shown, wherein the water heat exchanger 53 is allowed to function as a condenser by driving the compressor.


A computer-implemented method for decrypting, by a browser application, an encrypted portion of a fragment identifier within a uniform resource identifier includes receiving, by a browser application executing on a computing device, from a user, a uniform resource identifier including a delimiter and a fragment identifier, the fragment identifier comprising an encrypted portion. The method includes requesting, by the browser application, from an access control manager, decryption information associated with the fragment identifier. The method includes receiving, by the browser application, from the access control manager, the requested decryption information. The method includes decrypting, by the browser application, the encrypted portion of the fragment identifier with the requested decryption information.

The disclosure relates to distributing encrypted data. More particularly, the methods and systems described herein relate to distributing encrypted data contained in a uniform resource identifier.
Conventional systems for digital rights management are typically proprietary systems that provide functionality for securing—e.g., via one or more of encrypting, controlling access, and authenticating—shared data objects stored within the system and accessed by users of the system. However, such systems do not typically extend to securing data objects once the data objects are shared with individuals external to the system or for securing data objects created outside the system. Although individuals may implement cryptographic functions without the use of a digital rights management system, such functions typically require a level of technical sophistication unavailable to the average individual. Further, even for sophisticated users, there are a number of well-known drawbacks to standard cryptographic techniques. For example, symmetric key cryptography (e.g., the Advanced Encryption Standard (AES) in the United States) allows for password-protection of data objects but does not prevent authorized users from sharing the password with unauthorized users and is reliant upon the strength of the password.
Compounding the difficulty of secure message transmission, there are many protocols and applications that do not natively provide for encryption of messages, or provide an application programming interface to permit encryption or decryption functionality to be included. As a result, users must often resort to installing cumbersome specialized systems before they can send or receive encrypted messages, sometimes with no guarantee that the systems will operate smoothly with their preferred applications.

Methods and systems for decrypting an encrypted portion of a uniform resource identifier


An X-ray imaging apparatus includes a visible light imaging unit which captures an image of a visual field region with visible light, an X-ray irradiation unit which irradiates X-rays, an X-ray imaging unit which receives the irradiated X-rays and acquires a radiograph based on the X-rays, and a detection unit which detects an irradiated region irradiated with the X-rays based on the acquired radiograph.

1. Field of the Invention
The present invention relates to an X-ray imaging technique.
2. Description of the Related Art
Conventionally, an X-ray imaging apparatus used in a hospital or the like uses a cassette. After an exposed cassette is developed, the developed film is interpreted by using an observation device called a film viewer. With the recent advances in digitization, image data are directly displayed as images on a monitor and observed without development of a film. These operations are performed to make examination and to observe the inner state of the body, for example, whether there is a tumor or the state of bone fracture.
In addition, recent X-ray imaging apparatuses have begun to be used as surgical auxiliary apparatuses instead of apparatuses for examination. For example, in executing cardiac catheterization, an operator generally performs treatment by tracking a catheter inserted into the body while observing radioscopic pictures. In this case, it is thought that puncturing operation can be effectively performed by capturing images by an X-ray imaging apparatus and superimposing/displaying visible images and radiographs as guide information for puncturing on a TV monitor so as to allow the operator to grasp a specific portion at which puncturing should be started. For example, Japanese Patent Laid-Open No. 54-158984 discloses an arrangement configured to superimpose and display radioscopic pictures and visible images on a monitor.
The technique disclosed in Japanese Patent Laid-Open No. 54-158984, however, is aimed at the examination of semiconductor wafers, and hence gives no consideration to changes in the relative positional relationship between an X-ray tube and an X-ray detection unit. Consider, for example, a nursing apparatus using an X-ray sensor (X-ray detection unit) called a cassette which can be arbitrarily placed. In this case, when the relative positions of the X-ray tube and X-ray sensor are changed, it is impossible to detect a positional shift. For this reason, the X-ray imaging apparatus cannot inform the user of the occurrence of the positional shift. As a consequence, the user must recognize the occurrence of the positional shift upon occurrence of an error in a capturing result, and position the X-ray sensor and the X-ray tube again.

X-ray imaging apparatus, control method for x-ray imaging apparatus, program, and storage medium


A method of manufacturing a rotor magnet for a micro rotary electric machine is provided which includes steps of: a process in which a plurality of thick films, each of which is made of nanocomposite texture composed of αFe and R-TM-B where R is either 10 to 20 atomic % Nd or 10 to 20 atomic % Pr, B is 5 to 20 atomic % and TM is either Fe or partly Co-substituted Fe with 0 to 16 atomic %, are formed into a laminated magnet including isotropic nano-crystalline texture which contains αFe and R2TM14B and which has a remanence, Mr, of 0.95 T or more; and a process where the laminated magnet is multi-polar magnetized in-plane of the thick films.

1. Field of the Invention
The present invention relates to a method of manufacturing a rotor magnet for a micro rotary electric machine, and more particularly to a method of manufacturing a rotor magnet including a predetermined number of thick films layered on one another, which include magnetically isotropic nano-crystalline texture composed of a high saturation magnetized αFe phase and a high coercive R2TM14B phase, and which are multi-polar magnetized in-plane, to thereby provide a radial gap type micro rotary electric machine adapted to improve a high mechanical output power.
2. Description of the Related Art
A rotary electric machine for application field, for example, information and telecommunication devices has been commercially produced with its volume reduced to about 100 mm3 and is widely used. Such a rotary electric machine, when further miniaturized successfully, is expected to create a market for a motor adapted to output dynamic power or a generator adapted to produce electric power as a magnetic device in the so-called Power MEMS (Power micro-electromechanical system) field for new era.
Patent Document 1, for example, discloses a radial gap type brushless DC motor (RG-BLM) with an outer diameter of 1 mm or less and an axial length of 2 mm or less, which includes a hollow circular cylinder having a conductive cylindrical wall with slots and functioning as an excitation winding, and which is applied to an intravascular ultrasonography system. Also, Patent Document 2 discloses a fluid-cooled RG-BLM which has an outer diameter of 8 mm or less, and accordingly can be introduced into a vascular system of a body to thereby drive a blood pump located in the body, and in which an excitation winding is molded by resin containing Al2O3 thereby enhancing heat dissipation performance thus enabling achievement of an output of 5 W at 30,000 rpm.
As an example of a micro rotary electric machine as described above, a brushless DC motor is known which has a volume of 4 mm3 with an outer diameter of 1.6 mm and an axial length of 2 mm wherein a one pole-pair rotor having an outer diameter of 0.76 mm and including an Nd2Fe14B sintered magnet produced by electric discharge machining is coupled to a stator (refer to Non-Patent Document 1). Also known are a brushless DC motor with a volume of 62 mm3 (an outer diameter of 6 mm and an axial length of 2.2 mm) proposed by H. Raisigel (refer to Non-Patent Document 2), further a brushless DC motor with a volume of 20 mm3 (an outer diameter of 5 mm and an axial length of 1 mm) proposed by M. Nakano (refer to Non-Patent Document 3), and still further a brushless DC motor with a volume of 0.6 mm3 (an outer diameter of 0.8 mm and an axial length of 1.2 mm) proposed by T. Ito (refer to Non-Patent Document 4). The micro rotary electric machines described above undergo a significant decrease in torque due to the volume reduction according to the scaling law. However, since the mechanical output power P (W) is obtained by a product of: a constant number k=0.1047 (=π30); a revolution number N (r.p.m.); and a torque T (Nm), the decrease of the output P of a rotary electric machine resulting from the volume reduction can be supplemented to some extent by an increased rotational speed.
Various proposals have been presented for rotor magnets for use in the micro rotary electric machines as described above. For example, D. Hinz, et al. introduce an Nd2Fe14B system magnet with a thickness of 300 μm, which is die-upset at 750° C. and has a remanence, Mr,=1.25 T, a coercivity, HcJ,=1.06 MA/m, and a (BH)max=290 kJ/m3 (refer to Non-Patent Document 5). Also, J. Delamare, et al. represent that a torque of 0.001 mNm is generated by a motor which includes a rotor with an SmCo system magnet having eight pole-pairs and a stator disposed to oppose the rotor and which is driven at 100,000 rpm, or that an electric power of 1 W is produced by an electric generator which includes the above described rotor and stator and which is driven at 150,000 rpm (refer to Non-Patent Document 6). Further, Toepfer, T. Speliois, et al. report a so-called Power MEMS motor including a rotor with an Nd2Fe14B bonded magnet which is screen-printed on an FeSi substrate with a diameter of 10 mm so as to have a thickness of 500 μm, and which has a remanence, Mr,=0.42 T, and a (BH)max=15.8 kJ/m3 (refer to Non-Patent Document 7). In terms of torque per volume of a micro rotary electric machine, a radial gap type has an advantage over an axial gap type (refer to Non-Patent Document 8). Accordingly, a rotor magnet must be multi-polar magnetized in the radial direction to thereby fully derive the magnetic potential inherently present in a material.
A general two-pole permanent magnetic field of, for example, a DC motor can be pulse-current magnetized using a solenoid coil so as to achieve a magnetizing field of 4 MA/m or more. In this connection, in order to enable a micro rotary electric machine to achieve a higher dense torque, it is preferred to increase the number of magnetic poles as seen in the eight pole-pair rotor of J. Delamare, et al (refer to Non-Patent Document 6). When a rotor magnet is designed to have four or more poles with an inter-pole distance of about 1.5 mm, it is usual to apply pulse-current magnetization using a magnetization yoke of 1 turn/coil. However, considering the durability of the magnetization yoke (conductor), the peak value of pulsed current, IP, is set at a current density of up to about 25 kA/mm2 for the conductor. That is to say, if the inter-pole distance decreases, the conductor diameter is decreased, and consequently the peak value of pulsed current, IP, allowed is lowered. As a result, when the rotor magnet is further miniaturized and magnetized with an increased number of pole-pairs, saturation magnetization is inevitable thus making it difficult to fully derive the magnetic potential inherently present in a material.
H. Komura, et al. disclose a fine magnetization of a rotor magnet for use in such a micro rotary electric machine as described above, wherein a bonded magnet with an outer diameter of 2.6 mm, which includes an isotropic Nd2Fe14B magnetic powder (Currie temperature Tc=320° C.) prepared from a melt-spinning and cured with an epoxy resin, and which has a remanence, Mr,=about 0.7 T, is put in a magnetic field system fabricated from a 2-17 type SmCo system sintered magnet, is heated up to Tc (320° C.) or higher, and then cooled in the magnetic field system, whereby the rotor magnet is magnetized with eight pole-pairs. The magnetization described above is said to have achieved a magnetic flux almost three times as high as the magnetic flux achieved by the usual pulse-current magnetization of 1 turn/coil (refer to Non-Patent Document 9).
As for a magnet which includes an isotropic nano-crystalline texture according to the present invention composed of αFe and R2TM14Bs, usually an R-TM-B molten alloy is melt-spun making an amorphous thin ribbon of αFe and R-TBM, and then the amorphous thin ribbon is treated with heat and is thereby crystallized. Material obtained by rapid solidification of a molten alloy is limited to a powdery substance, such as a melt-spun thin ribbon having a thickness of about 15 to 40 μm. Accordingly, the powdery substance must be consolidated into a specific bulk by some means in order to be used as a magnet. Such consolidation of the powdery substance can be achieved, as disclosed by Toepfer, et al., T. Speliotis et al. and H. Komura, et al., mainly by mixing with a binder, for example, an epoxy resin, whereby a bonded magnet is formed.
Reference Documents which have so far been cited and/or will hereinafter be cited are listed as follows:    <Patent Document 1>PCT Patent Application Laid-Open No. H9-501820    <Patent Document 2>Japanese Patent Application Laid-Open No. 2002-532047    <Patent Document 3>Japanese Patent Application Laid-Open No. H9-23771    <Patent Document 4>Japanese Patent Application Laid-Open No. H11-288812    <Non-Patent Document 1>Mitsubishi Electric Corp. Technical Report—Volume 75 (2001), pp. 703-708, by S. Ohta, T. Obara, Y. Toda and M. Takeda    <Non-Patent Document 2>Proceedings of the 18th International Workshop on High Performance Magnets and Their Applications, Annecy, France (2004), pp. 942-944, by H. Raisigel, O. Wiss, N. Achotte, O. Cugat and J. Delamare    <Non-Patent Document 3>Proceedings of the 18th International Workshop on High Performance Magnets and Their Applications, Annecy, France (2004), pp. 723-726, by M. Nakano, S, Sato, R. Kato, H. Fukunaga, F. Yamashita, S. Hoefinger and J. Fidler    <Non-Patent Document 4>Journal of the Magnetics Society of Japan—Volume 18 (1994), pp. 922-927, by T. Ito    <Non-Patent Document 5>Proceedings of the 18th International Workshop on High Performance Magnets and Their Applications, Annecy, France (2004), pp. 76-83, by D. Hinz, O. Gutfleisch and K. H. Muller    <Non-Patent Document 6>Proceedings of the 18th International Workshop on High Performance Magnets and Their Applications, Annecy, France (2004), pp. 767-778, by J. Delamare, G. Reyne and O. Cugat    <Non-Patent Document 7>Proceedings of the 18th International Workshop on High Performance Magnets and Their Applications, Annecy, France (2004), pp. 942-944, by Toepfer, B. Pawlowski, D. Scha and B. Bel    <Non-Patent Document 8>Materials for the 143rd Workshop of the Applied Magnetics Society of Japan, Surugadai Kinenkan of Chuo University (2005), by F. Yamashita    <Non-Patent Document 9>Journal of Applied Physics—Volume 101 (2007), 09K104, by H. Komura, M. Kitaoka, T. Kiyomiya and Y Matsuo
With respect to the output of a micro rotary electric machine, a torque decrease due to volume reduction can be effectively supplemented by increasing rotational speed. However, an anisotropic magnet of, for example, D. Hinz, which has a remanence, Mr, of 1.2 T and an energy density (BH)max of 290 kJ/m3 (refer to Non-Patent Document 5), can be radially magnetized with a level of remanence, Mr, maintained in a limited case of magnetization for one pole-pair, but can hardly be oriented in a case of radial multi-polar magnetization for four or more poles thus making it virtually impossible to produce. Consequently, the above magnet can hardly be applied to a radial gap type rotary electric machine which is favorable in terms of torque density or output characteristics and, in a case of multi-polar magnetization with two or more pole-pairs, can be used only as a rotor magnet for an axial gap type rotary electric machine especially.
The anisotropic magnet described above is favorable for increasing torque for an axial gap type rotary electric machine, but unfavorable for increasing rotational speed due to S-T (speed-torque) drooping characteristic. Besides, the magnet has an electric specific resistance of 10-5 Ωcm or less, and therefore loss due to eddy current increases even if rotational speed is increased. Such loss due to eddy current turns into heat energy thereby raising the temperature of the magnet, which results in decreasing static magnetic field (flux loss). Accordingly, an anisotropic rare earth magnet produced by die-upsetting or sintering, which is known to provide a high energy density (BH)max value, causes an increase in loss and a decrease in mechanical output power especially when used as a rotor magnet for a radial gap type micro rotary electric machine for a high speed rotation thus synergistically lowering the efficiency of the micro rotary electric machine. As described above, a well-known anisotropic magnet having a high (BH)max value is not optimum especially in terms of output and efficiency of a radial gap type micro rotary electric machine, which restricts the structural and electrical design freedom of the micro rotary electric machine.
In view of the above anisotropic magnet with a high remanence and a high (BH)max, Toepfer, T. Speliois, et al. propose a rotor with a bonded magnet which has an electric specific resistance of 10−1 Ωcm and a remanence, Mr, of 0.42 T, and thereby intend to restrain eddy current for the purpose of increasing rotational speed (refer to Non-Patent Documents 7 and 8). The remanence, Mr, of about 0.42 T, however, generates too low a static magnetic field to be used for a rotor magnet of a micro rotary electric machine, which results in insufficient torque.
On the other hand, with regard to multi-polar magnetizing a magnet for a micro rotor in the radial direction, for example, H. Komura, et al. report a multi-polar magnetization wherein a bonded magnet, which is made such that an isotropic Nd2Fe14B powder made from a melt-spun thin ribbon is cured with epoxy resin and which has a remanence, Mr, of about 0.62 to 0.68 T, is heated up to 320° C. or higher and then cooled in the magnetic field system (Non-Patent Document 9).
Since the above compression-molded bonded magnet of H. Komura, et al. has an electric specific resistance of about 102 Ωcm, the problem associated with eddy current can be avoided, but the magnetic powder as a base constituent as well as the epoxy resin are inevitably degraded by heat during the multi-polar magnetization thus causing the magnetic potential to drop. Further, the bonded magnet is deteriorated in mechanical strength, which raises a major problem with reliability in resistance to centrifugal force at a high speed rotation, and the like. Moreover, the bonded magnet with a remanence, Mr, of 0.62 to 0.68 T produces too weak a static magnetic field for use as a rotor magnet of a micro rotary electric machine like the examples of Toepfer, et al, and T. Speliotis, et al., thus failing to obtain sufficient torque.

Method of manufacturing rotor magnet for micro rotary electric machine


This application discloses an indication method and apparatus, to support a requirement of a complex and fickle scenario. The method includes: generating and sending an arrangement indication used to indicate an arrangement manner of a reference signal, where the reference signal occupies at least one group of time frequency resources, and the arrangement manner is frequency division, time division, frequency division+code division, or time division+code division; in the frequency division manner, each group of time frequency resources occupy a symbol in time domain and at least one contiguous subcarrier in frequency domain; in the time division manner, each group of time frequency resources occupy at least one contiguous symbol in time domain and a subcarrier in frequency domain.

In a current communications system, radio channel information is obtained and compensated mainly based on a pilot signal or a reference signal (RS). In an orthogonal frequency division multiplexing (OFDM) system, an RS is distributed on different resource elements (RE) in two-dimensional time-frequency space in an OFDM symbol, and has a known amplitude and a known phase. In a multiple-input multiple-output (MIMO) system, each transmit antenna (a virtual antenna or a physical antenna) has an independent data channel. Based on an RS signal known in advance, a receiver performs channel estimation for each transmit antenna, and recovers sent data based on this.
Channel estimation is mainly used to compensate for channel fading and noise to re-establish a signal receiving process, and time domain and frequency domain changes of a channel are tracked by using an RS known by a transmitter and a receiver in advance. For example, to implement channel quality measurement and data demodulation of a higher-order multiple-antenna system, in a long term evolution-advanced (LTE-A) system, a plurality of RSs are defined, including: a cell-specific reference signal (CRS), a demodulation reference signal (DMRS), and a channel state information-reference signal (CSI-RS), where the DMRS is used to demodulate a physical downlink shared channel (PDSCH). A CSI-RS is used to perform channel measurement corresponding to an antenna port. A reference signal is introduced into R10 to measure channel state information in a transmission mode (TM) 9/10, and further to generate transmission configuration information related to scheduling, link adaptation, and MIMO transmission, and the like. Specifically, a system reports information such as a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indication (RI) based on a CSI-RS measurement result. A CRS is used to measure downlink channel quality to schedule a resource and support a link adaptation technology, and therefore is sent in all available frequency bands and all subframes.
In a current standard, an RS is usually generated based on a fixed sequence, and is mapped in a physical resource block (PRB) in a fixed density and a fixed manner based on a port quantity. Generally, an RS has a single function, and different RSs perform only functions corresponding to the RSs. In each current pilot pattern, mapping rules and functions of RS ports are all the same, and cannot be configured based on different scenarios. For example, a pilot pattern of a CSI-RS depends on CSI-RS configuration information, each configuration provides time-frequency resource mapping locations in a subframe for RSs corresponding to different port quantities, and RSs corresponding to 31 configurations may occupy a total of 40 REs in a normal subframe.
As communications technologies rapidly develop, a high speed, a high capacity, and a wide coverage already become main requirements of a future communications system, and it is critical to resolve undesirable property problems such as serious fading and interference caused by a constantly increasing communication range and a complex and diversified communication environment. As 5G new radio (5G NR) puts forward multi-scenario, multiband, and multi-transmission-mode requirements, how to enable an RS requirement of a system to be flexibly configured based on different scenarios or requirements, and ensure high-quality data transmission and high resource efficiency already becomes a problem that urgently needs to be resolved in a 5G NR system.

Reference signal indication method and apparatus to improve spectrum efficiency


Methods of patterning sidewall spacers are provided. In one aspect, a method of fabricating a circuit device includes forming a gate on a substrate and forming a first oxide spacer and a second oxide spacer adjacent to the gate. The width of the gate and the first and second oxide spacers is measured. The widths of the first and second oxide spacers are trimmed if the width of the gate and the first and second oxide spacers exceeds a preselected maximum value by exposing the first and second oxide spacers to a solution of ammonium hydroxide, hydrogen peroxide and water for a preselected like and rinsing with deionized water. Spacer width may be finely tuned to reduce the risk of weak overlap and to improve device characteristics through shorter channels.

1. Field of the Invention
This invention relates generally to semiconductor processing, and more particularly to a method of patterning insulating sidewall spacers using a wet etch.
2. Description of the Related Art
One variant of a basic conventional field effect transistor consists of a gate electrode stack fabricated on a lightly doped semiconductor substrate. The gate electrode stack consists of a gate dielectric layer and a gate electrode. A source region and a drain region are formed in the substrate beneath the gate dielectric layer and separated laterally to define a channel region. The gate electrode is designed to emit an electric field into the channel region. Changes in the electric field emitted by the gate electrode enable, or alternatively, disable the flow of current between the source and the drain. In many processes, the source/drain regions consist of a lightly doped drain (xe2x80x9cLDDxe2x80x9d) and an overlapping heavier doped region. The source/drain regions are electrically isolated laterally from adjacent conducting structures by isolation structures such as insulating trenches or field oxide regions.
The performance of field effect transistors is dramatically affected by drive current and channel transconductance. As a general rule, higher drive current and channel transconductance translate into more desirable device performance. Drive current may be enhanced by reducing the length of the channel, as drive current is inversely proportional to channel length. Both drive current and channel transconductance may be improved by reducing the resistance of the channel. Channel resistance may be reduced by decreasing doping level in the channel and by minimizing weak overlap conditions. Weak overlap occurs where the edges of the gate electrode and the drain are offset.
In a conventional process flow for forming a typical field effect transistor, a gate oxide layer is grown on a lightly doped silicon substrate and a conducting layer of aluminum or polysilicon is deposited on the gate oxide layer. The conducting layer is then anisotropically etched selectively to the gate oxide to define a gate electrode stacked on top of the gate oxide layer. Following formation of the gate electrode, a source and a drain are formed, usually by implanting a dopant species into the substrate. The gate electrode acts as a hard mask against the implant so that the source and drain are formed in the substrate self-aligned to the gate electrode. The substrate is then annealed to activate the dopant in the source and the drain. Salicidation steps frequently follow the formation of the source and drain.
In conventional processes incorporating LDD structures, a first set of oxide spacers is fabricated adjacent to the gate electrode prior to the LDD implant. The purpose of the first set of spacers is to provide a slight offset between the implanted substrate region and the gate edge so that damage to the edges of the gate electrode and the gate oxide layer and the substrate at the gate oxide edges is minimized. The first set of spacers is fabricated by forming a conformal layer of oxide over the gate electrode by chemical vapor deposition (xe2x80x9cCVDxe2x80x9d) or thermal oxidation and performing a subsequent anisotropic etch to define the spacers. The deliberate offset between the LDD edges and the gate edges is subsequently reduced by annealing. The goal of the anneal is to both activate the LDD and to eliminate the weak overlap.
Many conventional processes have incorporated RCA cleaning processes following the plasma etch to define the spacers. Some of these RCA process have employed etch mixtures of ammonium hydroxide and peroxide. Some unintentional etching activity on oxide films has been observed.
Following the LDD implant, a second set of insulating spacers is formed in what is largely a repeat of the earlier process used to fabricate the first set of spacers. The second set of spacers mask the substrate so that the second source/drain implant establishes overlapping heavier doped regions with an offset from the gate edges. In addition, the second set of spacers inhibit hot carrier injection from the later-formed silicide films on the substrate.
There are disadvantages associated with conventional techniques for patterning spacers. First, there is the potential for non-optimal device performance due to weak overlap.
Both the first and second sets of spacers are fabricated so that the width of each spacer falls within a specified range. Subsequent anneals to activate the source/drain regions are then tailored in view of the anticipated spacer width range to provide enough lateral diffusion of dopants to eliminate weak overlap. Control of spacer width is currently provided by monitoring the thickness of the conformal oxide layer that is deposited or grown over the gate electrode, and by monitoring the anisotropic character of the spacer etch. However, the outcomes of the oxide deposition or growth steps and the subsequent plasma etch are dependent upon a myriad of parameters, and thus do not always yield predictable results. Accordingly, later anneals may not yield the desired amount of lateral diffusion of source/drain dopants, and weak overlap may result.
In addition to weak overlap, conventional spacer processing may yield less than optimal channel transconductance and drive current due to the establishment of a larger than desired channel length. The widths of the spacers, in conjunction with the width of the gate itself, determine the pre-anneal channel length, and thus relate directly to the channel transconductance and the ultimate switching speed of the device. Accordingly, conventional spacer processes are typically designed to yield a spacer with a width that falls within a desired range that corresponds to a desired speed range. If the width of the spacers following plasma etch is larger than anticipated, the ultimate channel length may be larger than desired and result in degraded transconductance, drive current and switching speed.
Subsequent source/drain anneals may be lengthened in an attempt to narrow the channel length. However, lengthening anneals may consume thermal budget and lead to degraded device performance, particularly in processes sensitive to dopant migration, such as those used to fabricate p-channel devices.
The present invention is directed to overcoming or reducing the effects of one or more of the foregoing disadvantages.
In accordance with one aspect of the present invention, a method of fabricating a circuit device is provided that includes forming a gate on a substrate and forming a first oxide spacer and a second oxide spacer adjacent to the gate. The width of the gate and the first and second oxide spacers is measured. The widths of the first and second oxide spacers are trimmed if the width of the gate and the first and second oxide spacers exceeds a preselected maximum value by exposing the first and second oxide spacers to solution of ammonium hydroxide, hydrogen peroxide and water for a preselected time and rinsing with deionized water.
In accordance with another aspect of the present invention, a method of faceting a circuit device is provided that includes forming a gate on a substrate and forming an oxide layer over the gate. The oxide layer is anisotropically etched to define a first oxide spacer and a second oxide spacer adjacent to the gate. The widths of the gate and the first and second oxide spacers is measured. The widths of the first and second oxide spacers are trimmed if the width of the gate and the first and second oxide spacers exceeds a preselected maximum value by exposing the first and second oxide spacers to a solution of ammonium hydroxide, hydrogen peroxide and water for a preselected time and rinsing with deionized water.
In accordance with another aspect of the present invention, a method of fabricating a circuit device is provided that includes forming a gate on a substrate and forming an oxide layer over the gate. The oxide layer is anisotropically etched to define a first oxide spacer and a second oxide spacer adjacent to the gate. The width of the gate and the first and second oxide spacers is measured. The widths of the first and second oxide spacers are trimmed if the width of the gate and the first and second oxide spacers exceeds a preselected maximum value by exposing the first and second oxide spacers to a solution of ammonium hydroxide, hydrogen peroxide and water for a preselected time and rinsing with deionized water. A third spacer is formed adjacent to the first spacer and a fourth spacer is formed adjacent to the second spacer. The widths of the gate and the first, second, third and fourth oxide spacers is measured. The widths of the third and fourth oxide spacers are trimmed if the width of the gate and the first, second, third and fourth oxide spacers exceeds a preselected maximum value by exposing the third and fourth oxide spacers to solution off ammonium hydroxide, hydrogen peroxide and water for a preselected time and rinsing with deionized water.

Control of transistor performance through adjustment of spacer oxide profile with a wet etch


A pneumatic cleaner that can be worn as a backpack has a reduced unit overall depth. The impeller shaft is mounted at an acute angle. Tangential airflow chambers are disposed around the motor assembly and substantially surround the impeller. Two of the airflow chambers extend substantially the entire overall unit depth, and have lateral lengths that exceed the overall unit depth.

The present invention relates generally to pneumatic cleaners (vacuums, blowers, etc.), and more particularly to vacuum cleaners that can be worn as a backpack.
Over the years, vacuum cleaners and blowers have been adapted for many different uses. Generally, powerful units are large, bulky, and inherently noisy. Interior ducting is commonly used to dampen the noise produced by a motor and internal airflow. This ducting further increases the bulk of a unit.
Portability is a common concern. To improve portability, some vacuums or blowers (including those seen in U.S. Pat. Nos. 6,647,586; 6,115,879; 5,040,263; and 4,223,419) have been designed with a strap that can be slung over a user's shoulder. Others (including those seen in U.S. Pat. Nos. 6,473,933; 6,151,749; 6,066,211; and 4,944,065) have been designed with waist belts. Still others (including those seen in U.S. Pat. Nos. 6,857,163; 6,568,026; 6,553,610; 6,431,024; 6,295,692; 6,073,301; 5,267,371; 4,748,712; 4,658,778; and RE37,081) have been designed to be worn as backpacks.
One problem with backpack vacuums is that the size and depth of a quiet, powerful unit can make the unit awkward to carry.


A non-invasive method for continuous real-time monitoring of cerebrovascular blood flow autoregulation state includes simultaneous non-invasive monitoring of intracranial blood volume respiratory waves and lung volume respiratory waves, real-time decomposition of intracranial blood volume respiratory waves and lung volume respiratory waves into narrowband sinewave first harmonic components, determination therefrom of the phase shift between intracranial blood volume respiratory wave and lung volume respiratory wave first harmonics' and derivation of cerebrovascular autoregulation state from that phase shift value.

Cerebral blood flow autoregulation has been shown to be affected in a number of important clinical conditions, such as prematurity, birth asphyxia, stroke, head injury, carotid artery disease, hypertension and vasovagal syncope. Acute cerebral diseases (e.g., traumatic brain injury, stroke) frequently lead to a rise in intracranial pressure (ICP) and impairment of cerebral autoregulation (as described in the following references: Aaslid R. et al., Cerebral autoregulation dynamics in humans. Stroke 1989; 20:45-52; Czosnyka M. et al., Continuous assessment of the cerebral vasomotor reactivity in head injury. Neurosurgery 1997; 41:11-19.; Panerai R. B., Assessment of cerebral pressure autoregulation in humans—a review of measurement methods. Physiol Meas 1998; 19:305-338; and Schondorf R. et al., Dynamic cerebral autoregulation is preserved in neurally mediated syncope. J Appl Physiol 91:2493-2502, 2001).
Assessment of cerebrovascular autoregulation state (CAS) could be of vital importance in ensuring the efficacy of therapeutic measures in the case of brain injury and stroke. Continuous monitoring of CAS and CAS monitoring data based treatment of intensive care patients with brain injuries or stroke will reduce mortality and morbidity of such patients.
Various methods have previously been introduced to assess CAS. Discrete clinical tests (as described in the following references: Aaslid R. et al., Cerebral autoregulation dynamics in humans. Stroke 1989; 20:45-52; and Panerai R. B., Assessment of cerebral pressure autoregulation in humans—a review of measurement methods. Physiol Meas 1998; 19:305-338), like e.g. the cuff leg test (as discussed in reference Aaslid R. et al. Cerebral autoregulation dynamics in humans. Stroke 1989; 20:45-52) did not provide continuous monitoring data about CAS. There is a need for continuous real-time CAS monitoring because is it the optimal monitoring for use with CAS based therapy.
A few methods and techniques (such as those described in the following references: Czosnyka M et al., Continuous assessment of the cerebral vasomotor reactivity in head injury. Neurosurgery 1997; 41:11-19; and Schmidt B et al., Adaptive noninvasive assessment of intracranial pressure and cerebral autoregulation. Stroke 2003; 43:84-89, 2003) have been proposed for invasive, semi non-invasive and non-invasive monitoring of CAS. These methods are based on the estimation of the correlation factor between arterial blood pressure (ABP) and ICP slow waves or ABP and cerebral blood flow velocity (CBFV) slow waves (as described in the following references: Czosnyka M et al., Continuous assessment of the cerebral vasomotor reactivity in head injury. Neurosurgery 1997; 41:11-19; and Schmidt B et al., Adaptive noninvasive assessment of intracranial pressure and cerebral autoregulation. Stroke 2003; 43:84-89, 2003). In the case of intact cerebrovascular autoregulation the correlation factor between ABP and ICP slow waves is negative and close to −1.0. In the case of impaired CAS the same factor is positive and close to +1.0.
The disadvantages of slow invasive or non-invasive ABP and ICP wave correlation monitoring methods, include but are not limited to the following.
First, slow ICP waves are not permanent and the amplitude of such waves is too low (less than 3.0 mmHg during main part of ICU patients' continuous monitoring time) in order to measure such waves with sufficient accuracy. Also, non-invasive measurement or prediction of slow ICP waves adds additional errors and distortions of such waves. Further, if invasive slow ICP wave measurement is replaced by non-invasive transcranial Doppler (TCD) CBFV measurement, additional errors and distortions of such waves will occur. Moreover, slow ABP waves are also too small to measure with sufficient accuracy and non-invasively.
Also, the period of slow ICP or ABP waves is estimated to be from approximately 30 seconds to 120 seconds or more. In order to evaluate the CAS applying the slow wave method, it is necessary to accumulate the measured data during 4.0 minutes or longer. This is a relatively long time period and thus becomes a long term process. Long time period testing of CAS is not always effective because variability of CAS is a short-term process (as described in the following reference: Panerai R B et al., Short-term variability of cerebral blood flow velocity responses to arterial blood pressure transients. Ultrasound in Med. & Biol., Vol. 29, No. 1, pp. 31-38, 2003). Because the time delay of CAS monitoring data, secondary brain insults and injury can take place in ICU coma patients before appearance of the CAS monitoring data. The time delay of the slow wave CAS monitoring method is therefore too long for clinical practice of ICU patients monitoring and CAS based treatment.
Additionally, cerebrovascular autoregulation is complex, nonlinear and a multivariate mechanism with considerable short-term variability (as described in the following reference: Panerai R. B. et al., Short-term variability of cerebral blood flow velocity responses to arterial blood pressure transients. Ultrasound in Med. & Biol., Vol. 29, No. 1, pp. 31-38, 2003). A correlation factor can be applied without problems as an indicator of CAS only in linear autoregulatory systems. However, cerebrovascular autoregulation system is nonlinear (as described in the following reference: Panerai R. B. et al., Linear and nonlinear analysis of human dynamic cerebral autoregulation. Am J Physiol 1999a; 277:H1089-H1099). Any correlation factor between a reference signal (ABP slow wave) and a nonlinearly distorted cerebrovascular autoregulation system output signal (ICP or CBFV slow wave) would be a questionable indicator of CAS.
Accordingly, it is an object of the present invention to provide a method and apparatus for continuous real-time CAS monitoring that solves the problems and cures the deficiencies of the prior art methods, apparatuses and techniques.
The present invention provides a method for continuous real-time CAS monitoring which is based on simultaneous, non-invasive monitoring of intracranial blood volume respiratory waves (or other intracraniospinal characteristics related to the respiration processes) and lung volume respiratory waves (or other extracranial physiological characteristics related to the lung respiration processes), real-time decomposition or filtering of intracranial blood volume respiratory waves and lung volume respiratory waves into narrowband sinewave first harmonic components, determination therefrom of the phase shift between intracranial blood volume respiratory wave and lung volume respiratory wave first harmonics' and derivation of cerebrovascular autoregulation state from that phase shift value.
The intracranial blood volume (IBV) and lung volume (LV) respiratory waves have much shorter period (typically 2.5 seconds to 10.0 seconds) than slow waves. Respiratory waves are permanent in all conditions of ICU patients. Lung respiratory waves, as a reference signal for CAS estimation, can be measured non-invasively with accuracy much higher than non-invasive ABP slow wave measurements. Also IBV respiratory waves can be measured non-invasively with much higher accuracy than ICP or IBV slow wave measurements (as described in the following reference: Ragauskas et al., Implementation of non-invasive brain physiological monitoring concepts. Medical Engineering & Physics 25(2003) 667-678). It is not necessary to accumulate more than one period of non-invasively recorded IBV and LV respiratory wave data in order to estimate CAS. Because of that, the present invention provides a method of CAS monitoring which is much closer to a real-time method when compared with the slow wave method.

This patent is subject to a terminal disclaimer.

Method and apparatus for non-invasive continuous monitoring of cerebrovascular autoregulation state


A drill attachment (10) for decreasing the rotational speed/increasing the output torque of a cutting accessory (14) that is attached to a drill such as a surgical drill (10). The drill attachment has an input drive shaft (34) that is coupled to the drive shaft (16) of the drill to rotate in unison with the drill drive shaft. The input drive shaft rotates a set of axially fixed input planet gears (58). The input planet gears rotate a ring gear (66) that is fitted around the input planet gears. The ring gear rotates a set of axially fixed output planet gears (70). The planet gears rotate an output drive shaft (84). By the selective dimensioning of the drive shaft and gears the output speed/torque can be reduced and increased as desired.

In modern surgery, one of the most important instruments available to medical personnel is the powered surgical drill. Typically, this drill comprises a housing in which a motor is secured. The motor has a shaft that is connected to some type of chuck or other coupling assembly that is mounted to the housing. The coupling assembly holds a cutting accessory that is applied to the patient in order to perform a specific medical procedure. Some common cutting accessories are drill bits, burs and reamers. These accessories are used to drill into and/or separate sections of soft tissue and hard tissue, commonly referred to as bone. The ability to use surgical drills to actuate these and other cutting accessories has lessened the physical strain of physicians and other medical personnel that perform these medical procedures. Moreover, most surgical procedures can be performed more quickly and more accurately with powered surgical tools than with the manual equivalents that preceded them.
It is often desirable to increase the rotation force, the torque, developed by the motor internal to a surgical drill. Many drills are provided with internal gear assemblies that perform this function. Since an inevitable result of a gear assembly's increasing torque output is a decrease in rotational speed, these gear assemblies are referred to as speed reduction gear assemblies. Generally, the input-to-output speed reduction factor and the input-to-output torque amplification factor of these gear assemblies are identical. Moreover, manufacturers of surgical drills often provide removable drill attachments for coupling to drills that have their own speed reduction gear assemblies. The ability to selectively couple a drill attachment to a surgical tool makes it possible for a surgeon to even further increase the torque available to the cutting tool coupled to the drill. Often, these drill attachments are designed to reduce the speed/increase the torque by a pre-set whole number ratio. For example, drill attachments with internal gear assemblies that decrease speed of the motor drive shaft by 3:1 or 4:1 have been provided. (It should be understood that the above ratio refers to the relationship of the input shaft speed to the output shaft speed. The reciprocal of these ratios give the relationship between torque input and torque output.)
Often, planetary gear assemblies are used as speed reduction gear assemblies for both surgical drills and the removable drill attachments designed for use with these drills. A planetary gear assembly has a centrally located sun gear that is directly coupled to the drill drive shaft that provides the basic motive power. A set of gears, referred to as planet gears, are located around and engage the sun gear. A fixed ring surrounds the planetary gears. The inner surface of the ring has teeth which the planetary gears engage. The planet gears are connected to a common planet carrier. The planet carrier has a number of arms to which the individual planet gears are attached. When the sun gear is rotated, the sun gear transfers the rotational energy it receives to the planet gears. The planet gears, in turn, rotate both around their own axes and the axis of the sun gear. The rotation of the planet gears about the sun gear causes a like rotation of the planet carrier.
Planetary gear assemblies and other gear assemblies have proven to be useful assemblies for reducing the speed/increasing the torque of the shafts connected to surgical drills. However, to date, it has been difficult to provide a removable drill attachment with a planetary gear assembly or other gear assembly that can be used to achieve a 2:1 speed reduction. This is because physically, owing to the relationships between the components of a conventional planetary gear assembly, it is impossible to dimension the components so that they cause an exact 2:1 speed reduction. The only way it is possible to form a conventional planetary gear assembly that achieves approximately a 2:1 speed reduction is to provide it with very small planet gears. Such an assembly would not be able to function for a long time at the high rotational speeds at which most surgical drills operate. Attempts to provide other gear assemblies that reduce rotational speed/increase torque by a factor of 2 have proven unsuccessful for use with surgical drills. While these other gear assembles provide the desired speed reduction/increased torque, the direction of rotation of their output shafts is reversed from the direction input shaft rotation. It is impractical to provide removable drill attachments chucks with these gear assemblies since the change in rotation of the associated cutting accessory could be confusing to a surgeon in the middle of a surgical procedure.


A parallel data storage device includes a data storage medium having a first cluster and a second cluster. The first cluster includes a first patch and the second cluster includes a second patch. The parallel data storage device also includes a first reader for reading the first patch of the first cluster and a second reader for reading the second patch of the second cluster. A first multiplexer is used for addressing the first cluster while a second multiplexer is used for addressing the second cluster. The first and second readers are arranged in a single column such that the first reader is electrically connected to the first multiplexer and the second reader is electrically connected to the second multiplexer.

Some portable media storage devices include readers overlying a data storage medium that may move relative to the readers using one or more micro-movers. In some cases, the data storage medium is laid out and the readers are configured such that traditional column/row addressing schemes may be used to address data stored in the data storage medium. However, due to production processes and other considerations, the data storage medium may have an irregular shape leading to an underutilization of an available usable space of the data storage medium when subdivided into rectangular columns and rows. It would thus be desirable to be able to substantially optimize the utilization of the space in the data storage medium.


A foil hood is gathered into a stack of folds and then fitted over four fingers in inner positions of the fingers with the hood open downward. A holding device then clamps the hood against the fingers, the fingers are spread into outer positions to transversely stretch the hood, and then the holding device is disengaged. Finally the fingers are moved downward along the load such that the closed end of the hood engages on the top of the load and the hood is pulled upward fold-by-fold off the fingers through a predetermined position at which generally all of the folds have been pulled off the fingers to an end position at which the hood is stretched vertically over the load and all of the folds have been pulled off the fingers.

In one type of the known apparatus for wrapping, the folding of the foil that is normally closed at one end is effected by gathering right on the pull-down device. The pull-down device has spreadable tensioning corners, whereby preferably in each corner region of the pull-down device there is a respective gathering roller and an opposite counter roller paired together and both rotatable about horizontal axes. After engagement of the pull-down device into the foil hood, the foil hood is tensioned between the counter rollers and the gathering rollers and the gathering rollers are rotated to form the folds. After the fold-formation the tensioning corners are spread apart so that the foil hood is stretched so that it can subsequently be drawn over the one- or multi-part load. To this end the pull-down device is dropped over the one- or multi-part load so that the foil hood engages the top of the one- or multi-part load and is thus stopped. During downward movement the folds that run around the foil hood are progressively pulled off so that then the pull-down device reaches its lowermost position, the entire foil hood has no more folds and the one- or multi-part load and if necessary the underlying pallet are wrapped.
In order to avoid that during stretching of the foil hood it is pulled off the tensioning corners, it is gripped between the gathering wheels and the counter rolls. The disadvantage of this is that the foil hood is only held in a very limited region so that the foil hood can only be sufficiently stretched at its upper region, as otherwise the foil hood would be damaged.
In another type of the known apparatus there is a gathering device separate from the pull-down device. The foil hood is gathered by the gathering device and then is taken over by a separate movable pull-down device. The pull-down device has in the corner regions rod-shaped holding elements directed in the pull-down direction and serving to hold the gathered foil hood taken over from the gathering device. The foil hood is subsequently stretched by spreading of the holding elements and the pull-down device is shifted downward along the one- or multi-part load for pulling-down. The disadvantage of this is that during stretching the foil hood is not solidly gripped so that the foil hood cannot be sufficiently stretched since it would slip partly off the holding elements.

Method of fitting a packaging hood over a load

MSK-Verpackungs-Systeme Gesellschaft Mit Beschrankter Haftung


Disclosed is an electrolyte for a rechargeable lithium battery including 5 to 40 volume % of at least one fluorine-substituted ether compound represented by R1—O—R2 (wherein R1 and R2 are alkyl groups substituted with fluorine), having a substitution ratio of hydrogen with fluorine of 57 to 86%, a viscosity of 0.9 to 2.3 cp, and a boiling point of at least 88° C., and 60 to 90 volume % of a non-aqueous organic solvent having a flash point of at least 80° C.

The conventional organic solvents used in electrolytes for rechargeable lithium batteries include cyclic esters such as ethylene carbonate and propylene carbonate; chain esters such as dimethyl carbonate and propionic ether; and cyclic ethers such as tetrahydrofurane. However, the conventional organic solvents easily decompose during oxidation and reduction of the battery, or they exhibit poor cycle life characteristics.
Recently, attempts have been made to add organic fluorine-included ethers to the organic solvents in electrolytes, which do not decompose during oxidation and reduction of the battery. The organic fluorine-included ethers have a high fluorine content which results in improved stability during the decomposition, but they are not very compatible with other organic solvents used in the electrolyte.

Electrolyte for rechargeable lithium battery and rechargeable lithium battery comprising same


In general, a method of securely transmitting data features an operation of authenticating a user of a platform during a Basic Input/Output System (BIOS) boot process. In response to authenticating the user, a first keying material is released from a token communicatively coupled to the platform. The first keying material is combined with a second keying material internally stored within the platform in order to produce a combination key. This combination key is used to decrypt a second BIOS area to recover a second segment of BIOS code.

1. Field
This invention relates to the field of data security. In particular, the invention relates to a platform and method for protecting information through a secure boot using user authentication and/or hardware configurations.
2. Background
Personal computers (PCs) typically include different types of storage components to store programs and data. These storage components include random access memory (RAM), read-only memory (ROM), and memory devices that are located external to the PC (e.g., hard disk or a floppy disk). To load an operating system on a PC, it is necessary to initialize or "boot" the PC by loading and executing boot code. Because the PC typically is unable to access external devices until after it is booted, the boot code is stored internally within the PC.
Typically, a ROM component is used to store the boot code. This boot code, normally referred to as "boot block," is obtained from the ROM and executed. The boot block is coded to (i) locate Basic Input/Output System (BIOS), (ii) load the BIOS for execution, and (iii) pass control to the BIOS. Thereafter, the BIOS checks Option ROMs, loads the operating system (OS) loader, and passes control to the OS loader.
Currently, enhanced security features are being implemented in platforms with greater regularity. However, current security features lack the combination of both user authentication and secure boot functionality.

Platform and method of creating a secure boot that enforces proper user authentication and enforces hardware configurations


A cushion lift assembly for raising and lowering the front and rear portions of an automobile seat independently and/or simultaneously. The cushion lift assembly includes mounting members and a pair of connecting members interconnecting the mounting members. The connecting members are formed from three stamped members including a first elongated stamped member and two bracket members mounted near opposite ends of the first stamped member. Each of the stamped members includes a rib formed therein. The ribs cooperate to define an annular opening in which a pivot member is received.

1. Field of the Invention
The present invention relates to a lift assembly for the seat of an automobile.
2. Description of the Related Art
Automobile seats provided with power seat adjusters include a mechanism designed to raise and lower the seat in a substantially vertical direction. This mechanism is a cushion lift assembly having mounting members to which the automobile seat is secured. The mounting members are positioned substantially parallel to one another with a pair of connecting members interconnecting opposite ends of the mounting members. The cushion lift assembly also includes mounting points for electric motors which are provided to cause rotation of the connecting members and thus the seat.
Several methods may be used to link the connecting members and the mounting members. One such method includes a mechanical linkage which is the subject of U.S. patent application Ser. No. 10/164,859, assigned to the assignee of the present invention. The swage mechanical linkage of the above-identified patent application is used to interconnect the connecting members and mounting members. The connecting members are formed from tubing and are provided with inserts fixedly received in each end thereof. The insert has a large diameter portion fixedly received in the connecting tube and a smaller diameter portion providing a bearing surface for the cushion lift assembly. The end of the tube having the insert mounted therein is received within an aperture formed in a linkage. The linkage is used to link the connecting member and the mounting member such that the opposite end of linkage is secured to the mounting member. The smaller diameter portion of the insert engages a track mounted in the automobile to mount the cushion lift assembly therein. Electric motors are also mounted on the track to actuate the connecting members and thus the cushion lift assembly to raise and lower the front and rear portions of the seat either independently and/or simultaneously.
Alternatively, the insert portion of the assembly may be integrally formed with a solid rod or connecting tube having uniform strength along its length, or secured thereto by welding, brazing or the like.
These methods of manufacturing the cushion lift assembly can be problematic and expensive. With the swage concept, assembly of multiple components requires additional time and thus increases labor costs. The use of the welded linkages has problems including increased cost, the potential for cold welds wherein the weld metal does not penetrate the base metal, and warping of components during the welding process. Additionally, the use of tubing for the connecting member may be costly and the tolerances may be loose.


An implantable device for intrafascicular stimulation and/or sensing of a peripheral nerve, including a blocking element adapted for wrapping a nerve, comprising an access point and an exit point, and an electrode adapted to traverse the blocking element via the access point and the exit point having a distal end, a proximal end and an elongated body in between, the electrode being electrically isolated from the surrounding environment except that for an active site. In another aspect, the invention features a system comprising the implantable device of the invention operably coupled with an external device such an electrostimulator and/or a sensing device for sensing and recording electrical nerve signals.

A nerve is a cordlike structure conveying impulses between some part of the central nervous system and some other region of the body. A nerve is made of individual nerve fibers (axons) with their sheaths and supporting cells, small blood vessels, and a surrounding connective tissue sheath. Each nerve fiber is surrounded by a cellular sheath (neurilemma) from which it may or may not be separated by a myelin sheath). A group of such nerve fibers surrounded by a sheet of connective tissue (perineurium) is called a fasciculus. The fasciculi are then bound together by a thick layer of connective tissue (epineurium) to form the nerve.
Neurologists have long sought an electrode device which could establish stable mechanical and electrical contact with a large number of individual axons within a nerve. Such a device would find wide medical application for recording neurological impulses, facilitating the analysis and interpretation of such impulses, and delivering electrical stimuli to target nerve fibers as a reaction to such analysis or as a result of external input. The ideal electrode device would be adapted to the anatomy of the nerve so that it could penetrate the nerve in a non-destructive fashion in order to form focused electrical contacts with a very large number of individual nerve fibers.
Peripheral nerve interfaces (Navarro et al., J. Peripher. Nerv. System, 10, 229-258, 2005; Shultz and Kuiken, PM&R, 3.1, 55-67, 2011; Ciancio et al., Frontiers in neuroscience, 10, 2016) have been used to record signals from, and to inject electrical current in, the human nerves. Among these, FINE, CUFF, LIFE, TIME and Utah array electrodes have been used on humans.
The FINE or CUFF electrodes are stable (in terms of biocompatibility and functionality) in a long-term implant in the human nerves because they are placed totally around them. On the other side, they are not selective, exchanging information with more than a nerve fascicle at time. This implicates, e.g. in the case of sensory feedback restoration, that they can elicit a localized sensation without modulating its intensity (Badia et al., J. Neural Eng., vol. 8, no. 3, 2011).
LIFE/TIME/Utah array on the other hand, are more selective and then allow transmission of gradual information, e.g. touch intensity. However, they are less stable. In particular, LIFE and TIME are constituted by a substrate of e.g. polyimide on which conductive material is printed. Their stability during long-term implants has not been proven yet. The implanting procedure, even though quite complicated, favours a stable mechanical connection between the electrodes and the nerve. Utah array electrodes are stable in the human body (proven through brain implants) but the implanting technique in a peripheral nerve is not efficient since the electrode can move once the surgery is over.
Several medical devices have exploited peripheral nerve interfaces for hand prosthesis movement control and sensory feedback restoration (Raspopovic et al., Science translational medicine 6.222: 222ra19-222ra19, 2014; Tan et al., Science translational medicine, 6 (257), pp. 257ra138-257ra138, 2014), bladder control (clinical practice), epilepsy/depression treatment (e.g. Cyberonics), foot drop treatment (e.g. Ottobock), sight restoration (e.g. Second Sight).
A plethora of documents describe peripheral nerve interfaces. For instance, U.S. Pat. No. 4,969,468 and WO2016005400 disclose a cuff interface that presents an array of spikes in the inner face. The cuff is used as a support for the spikes for stably inserting them in the nerve.
U.S. Pat. No. 5,634,462 describes a FINE electrode that, according to the configuration, shapes the nerve in different ways to maximize the selectivity of the interfacing with the nerve itself.
WO2012149039 and US2014128951 disclose an electrode constituted by a group of cables, each of which composed by a conductive material surrounded by an insulating sheath. The cables are inserted longitudinally in the nerve.
EP1726329 discloses a hermetically sealed three-dimensional electrode device particularly useful for neuron interface and more specifically as a cortical implant. It includes an assembly (array) of electrically conductive electrodes arising from a substrate where the electrodes are hermetically bonded to the substrate. The electrodes also include an insulating layer which leaves at least one zone or at least one hole exposed for making focused electrical contact with the tissue. One major problem with this implant, as for e.g. the Utah arrays, is its instability if used on a peripheral nerve and the need to establish in advance the length of each electrode needle, or the position of the electric reveal thereon, for an efficient tissue stimulation. A similar teaching is reported also in U.S. Pat. No. 4,969,468.
Despite a large amount of research and development performed in this field, there is still a need for an implantable device which guarantees a stable and durable bond with a peripheral nerve while assuring an efficient and selective electrical contact with single nerve fascicles.

ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE


An electronic device includes multiple IC dies stacked in an offset stacking arrangement on a substrate. Each IC die includes electrically isolated step pads that facilitates transmitting a dedicated signal between a (beginning) substrate bonding pad and a selected (terminal) contact pad of any die by way of short bonding wires that extend up the stack between the electrically isolated step pads. A memory devices includes stacked memory IC die, wherein “shared” signal transmission paths are formed by associated bonding wires that link corresponding contact pads of each memory die, and dedicated select/control signals are transmitted to each memory die by separate transmission paths formed in part by associated electrically isolated step pads. Substrate space overhung by the stack is used for passive components and IC dies. Memory controller die may be mounted on the stack and connected by dedicated transmission paths utilizing the electrically isolated step pads.

As the need increases for memory devices that are both smaller and have larger data capacities, advancements in stacked IC packaging techniques have been developed to facilitate this need. Stacked IC packaging generally involves stacking multiple integrated circuit dies onto a substrate within a single IC package.
One stacked IC packaging approach involves stacking the IC dies in a "pyramid" stacking arrangement in which a smaller die is stacked on a larger die, with both dies wire bonded to the substrate. The use of wire bonding necessarily requires that access to bonding pads of each of the dies be available; consequently, the upper die, when stacked on the lower die, must be small so as to not inhibit access to the bonding pads of the lower die. The "pyramid" stacking arrangement has, for example, been used with same function dies (e.g., two Flash memory dies) or different function dies (e.g., one Flash memory die and one SRAM die). Stacking of two or three dies has been done for stacked Chip Scale Packages (stacked CSP) and stacked Thin Small Outline Packages (TSOP). A disadvantage of the "pyramid" stacking arrangement is that the dies must be different sizes, which presents a problem in memory device applications where several like-sized memory dies are used.
Another conventional IC packaging approach that facilitates stacking like-sized dies involves placing a spacer (e.g., a relatively thick insulator) between the dies. Although the spacer provides sufficient space between the dies so that wire bonded to the lower die is made possible, the spacer disadvantageously either makes the IC package thicker, or limits the number of dies that can fit within the IC package of a predetermined thickness.
FIG. 19 is a simplified cross-sectional side view showing an electronic device 200 produced in accordance with a stacked IC packaging technique that is disclosed in Published U.S. Application No. 20070218588. Device 200 includes IC dies 212 to 218 disposed in a "staircase" stacking arrangement on a substrate 201, and are respectively connected to a finger pad 203 by way of wire bonds 222 to 228. Adhesive layers 232 to 238 are disposed under each IC die 212 to 218. A molded plastic housing 240 is formed over substrate 201, dies 212 to 218 and wire bonds 222 to 228.
The "staircase" stacking arrangement of device 200 avoids the problems of the spacer approach (discussed above) by exposing bond pads on each IC die without requiring a thick spacer between the dies. However, device 200 has several problems associated with the formation of wire bonds 222 to 228 between each IC die 212 to 218 and substrate 201. First, by forming wire bonds to each IC die, the number of IC die that can be stacked in the "staircase" stacking arrangement of device 200 is limited due to the increasing length of the wire bonds to the uppermost IC die (e.g., wire bonds 228). Further, because each IC die 212 to 218 is connected at its lower end to finger pad 203, the size of finger pad 203 must be made large to accommodate a potentially large number of wire bonds (thereby wasting substrate surface area in applications where a smaller number of die are used). Moreover, the longer wire bonds (e.g., wire bonds 226 and 228) are subject to greater parasitic inductances than shorter wire bonds, and the overlapping wire arrangement increases the risk that longer wire bonds may sag and short against the underlying shorter wire bonds. Additionally, as understood by those in the art, longer wire bonds are more prone to the wire sweep problem during molding process that can cause electrical open defects. Finally, the overlapping wire bond arrangement makes repair and reworking of a damaged or misplaced wire bond difficult without removing the wire bonds disposed over or adjacent to the damaged/misplaced wire bond.
FIG. 20 is a simplified cross-sectional side view showing an electronic device 300 produced in accordance with a "staggered" stacking arrangement, also disclosed in Published U.S. Application No. 20070218588, in which IC dies 312 to 318 disposed in an offset "staggered" arrangement on a substrate 301 such that every other die is connected to one of a first finger pad 303 or a second finger pad 305 by way of wire bonds 322 to 328. This approach reduces the length of the wire bonds extending to the uppermost IC die and may somewhat simplify repair/rework, but still has many of the problems discussed above with reference to the "staircase" stacking arrangement (e.g., the size of finger pads 303 and 205 must be made large, the wire bonds are subject to parasitic inductances, the overlapping wire arrangement increases the risk of sagging and shorting, and is subject to the wire sweep problem).
FIG. 21 is a simplified cross-sectional side view showing an electronic device 400 produced in accordance with another "staircase" stacking arrangement that is also disclosed in Published U.S. Application No. 20070218588. Similar to device 200 (discussed above), bonding wire 432 is connected between a finger pad 403 and a lowermost IC die 412. Device 400 differs from device 200 in that, instead of having each wire bond extend from the substrate to its associated IC die, subsequent bonding wires 424 to 428 of device 400 are connected between adjacent IC die (i.e., bonding wire 424 is connected between die 412 and die 414, bonding wire 426 is connected between die 414 and die 416, and bonding wire 428 is connected between die 416 and die 418). This wiring arrangement is utilized in, e.g., memory applications where "shared" (e.g., addressing and data) signals are transmitted to all of the memory dies. However, this arrangement has a problem in that it does not provide for dedicated (unshared) (e.g., Chip Select and Chip Enable) signals that are unique to each of the memory die. That is, the only way to send dedicated signals to each of IC die 412 to 418, based on the teachings of Published U.S. Application No. 20070218588, is to provide separate wire bonds extending from substrate 401 to each of IC dies 412 to 418 (i.e., similar to wire bonds 222 to 228, described above with reference to FIG. 2), which would be subject to the same problems as those described above with reference to FIG. 2.
FIG. 22 is a simplified cross-sectional side view showing an electronic device 500 produced in accordance with yet another stacking arrangement that is also disclosed in Published U.S. Application No. 20070218588. Similar to device 400 (discussed above), IC dies 512 to 518 are arranged in "staircase" stacking arrangement on substrate 501, and bonding wires 522 to 528 are connected between finger pad 503 and IC die 512, and between IC dies 514 to 518 in the manner that supports "shared" signals. In addition, another (e.g., a memory control) IC die 519 is mounted on IC die 518, and wire bonds 529 are connected between corresponding finger pad 505 and IC die 519 in order to support dedicated signals transmitted to and from IC die 519. This arrangement has problems similar to those discussed above with reference to FIG. 4, and in addition re-introduces the problems discussed above with reference to FIG. 2 regarding longer wire bonds.
What is needed is a method for producing electronic devices including stacked IC (e.g., memory or logic) dies that avoids the problems associated with the conventional stacking arrangements set forth above.

High density memory device manufacturing using isolated step pads


A capacitive sensor device for a handheld radio transceiver for estimating a specific absorption rate (SAR) can be coupled with at least one first electrode, wherein during the operation of the handheld radio transceiver the first electrode is at the same time a sensor electrode of the capacitive sensor device and an antenna of the handheld radio transceiver. Moreover a handheld radio transceiver with such a capacitive sensor device can be provided. Moreover, a method can be provided for adjusting a transmission power of a handheld radio transceiver, wherein an approach of an object to the handheld radio transceiver is detected and wherein depending on the detected approach the transmission power of the handheld radio transceiver is increased or reduced.

The specific absorption rate SAR is a measure for the absorption of electromagnetic fields especially in biologic tissue. The specific absorption rate SAR is moreover an important indicator for the irradiation of a high-frequency transmission signal from a radio system, for example a handheld radio transceiver, and its coupling into the human body. The coupling of the high-frequency transmission signal into the human body represents a risk factor in the use of handheld radio transceivers, for example mobile phones, because the absorption of the electromagnetic field energy leads in any case to a warming of the tissue, which can lead to changes in the tissue, which can be the cause of cancer.
There is therefore the necessity to hold the transmission power of handheld radio transceivers, especially if they are situated near the human body, as low as possible, in order to reduce the level of contamination for the body. A statement concerning the coupling of the high-frequency transmission signals into the human body could be used in order to adapt the transmission power of the handheld radio transceiver accordingly.
Two different factors have a substantial influence on the specific absorption rate SAR of a handheld radio transceiver, i.e.    Factor 1: the transmission power effectively irradiated by the handheld radio transceiver (HF transmission power), and    Factor 2: the proximity of the antenna or antennas to the human body.
In order to be able to determine or estimate the specific absorption rate SAR as exactly as possible, it is advantageous to evaluate or to detect both factors. I.e., that advantageously both the HF transmission power effectively irradiated and the proximity of the antenna(s) to the body are considered in the determination or valuation of the specific absorption rate SAR. If both factors are considered, a good approximation of the power coupling to the real power coupling into the human body is possible.
If however only one of the two factors is considered, for the other factor the worst case has to be presumed in order to maintain the level of contamination for the body as low as possible. This however has the disadvantage that the transmission power has to be reduced beyond the necessary, which has a negative effect on the transmission properties of the radio system or handheld radio transceiver.
For the detection of the HF power effectively irradiated by an antenna of a handheld radio transceiver and for the detection of the distance of a human body from the handheld radio transceiver or from the antenna of the handheld radio transceiver, solutions are known from prior art. One solution for detecting the irradiated HF power is shown in regard to FIG. 1. FIG. 2 shows a solution for detecting the distance of a human body from an antenna of a handheld radio transceiver.
FIG. 1 shows an approach to a solution known from prior art for detecting the HF transmission power effectively irradiated by an antenna. A HF transmitter, which here consists of a signal generator for generating a HF-carrier signal, a signal production, by which the transmission information to be transmitted is provided, and a mixer, generates a modulated HF transmission signal which is led to a power amplifier PA. With the power amplifier PA the HF transmission signal is brought up to transmission level. The amplifier signal is then, by a circulator and an antenna switch, led to the antenna A, where it is finally irradiated.
The circulator itself is not necessary for normal operation. The circulator is provided here in order to allow in the normal operation a SAR valuation of the signal irradiated at the antenna.
By the circulator the waves reflected by the antenna A are diverted to a demodulator, so that the reflected waves do not appear on the power amplifier PA. The power amplifier PA is always well adapted and delivers its rated power, so that the rated power can be supposed to be constant. In this way it is possible, exclusively based on the changing power of the reflected wave to make a statement concerning the power effectively irradiated by the antenna A. The demodulator here fulfills the function of a rectifier, because only a measure for the power is needed, but not for the transmission information itself. The demodulator is coupled with a SAR evaluation unit and can consist of a DC voltage amplifier and an analog-to-digital converter or a simple comparator. The exact configuration of the SAR evaluation unit mainly depends on how precisely the SAR-valuation has to be.
The approach to a solution shown in FIG. 1 for detecting the HF transmission power effectively irradiated by the antenna is especially suitable for systems with constant envelope, like for example GMSK-/GFSK systems (GSM/DECT). With this approach to a solution above all the direct correlation of the SAR estimation with the HF transmission signal is advantageously exploited, because the power effectively irradiated is detected exactly where the transmission signal produces the coupling into the human body, i.e. at the antenna.
FIG. 2 shows an approach to a solution known from prior art for detecting an object or human body near the handheld radio transceiver. For detecting a distance or an approach of an object or human body to a handheld radio transceiver here a capacitive sensor is provided, which works according to a so-called loading method. In a capacitive sensor operating according to the loading method a sensor electrode is fed with an electric alternating signal of a generator G1. By means of a receiver E1 (or reception path E1) an evaluating device can detect and evaluate the capacitive load of the generated signal. The evaluator can be a component of a SAR evaluation unit.
Generally speaking, the smaller the distance of the electrode from the object or the human body, the greater is the detectable capacitive load. It is however disadvantageous that for a sufficiently good correlation between the antenna signal and the sensor result of the capacitive sensor the electrode must be close to the antenna. By the proximity of the sensor electrode to the antenna the adjustment of the antenna is reduced, so that worse transmission/reception properties for the handheld radio transceiver result. In order to not substantially influence the transmission/reception properties of the radio system by the sensor electrode, it is therefore necessary to arrange the sensor electrode at a certain distance from the antenna. In this way however a correlation between the antenna signal and the sensor result of the capacitive sensor cannot always be guaranteed. In order to nevertheless ensure that the level of contamination for the human body does not exceed a predetermined value, it is therefore necessary to reduce the transmission power of the handheld radio transceiver more than necessary.

Capacitive sensor device and radio transceiver with a capacitive sensor device and a method for adjusting a transmission power of a handheld radio transceiver


A high output current wideband output stage/buffer amplifier that has reduced quiescent current requirements. The output stage/buffer amplifier includes a diamond follower circuit having a pair of complementary output load-driving bipolar junction transistors (BJTs), a pair of pre-driver BJTs, and a plurality of current boost BJTs. As the base current of one of the driver transistors starts to increase in response to an increasing load current, the current through a corresponding pre-driver transistor decreases, thereby increasing the collector current of a corresponding boost transistor. The increased collector current of the boost transistor is fed back to a current mirror, causing a concomitant increase in the base current of the driver transistor.

The present application relates generally to output stages for analog circuits, and more specifically to high output current wideband output stages for amplifiers.
Amplifiers are known that employ a number of stages to produce amplification of electrical signals. A conventional amplifier generally includes one or more amplifying stages followed by an output stage. Output stages typically serve a number of functions. For example, an output stage may be included in a buffer amplifier to provide (1) an appropriate output impedance, (2) a large output voltage swing, and/or (3) a large output current drive. Output stages may also be configured to provide additional amplification for amplifier circuits.
Conventional amplifier output stages have drawbacks, however, particularly when the output stages are implemented using bipolar junction transistors (BJTs). This is because for output stages that include BJTs, high beta (β) and good saturation characteristics are often traded-off against amplifier speed. For example, because the β of high frequency BJTs is normally relatively low, the current gain of such transistors can also be relatively low. As a result, when high frequency BJTs are employed in the output stage of a buffer amplifier, large bias current sources are usually required to enable the output stage to produce a sufficiently large output current drive. However, such large current sources can significantly increase the quiescent current of the output stage, thereby increasing the overall power requirements of the amplifier.
One way of increasing the current gain of an amplifier is to increase the number of stages. However, although the inclusion of additional stages may improve the output drive current capability of an amplifier, such an approach can increase the quiescent current, reduce the output voltage swing, and reduce the bandwidth of the amplifier.
It would therefore be desirable to have an improved output stage for an amplifier. Such an output stage would include high frequency transistors and would provide high output current drive capability without sacrificing amplifier speed. It would also be desirable to have an output stage that maintains a high signal current-to-quiescent current ratio for increased amplifier efficiency.

High output current wideband output stage/buffer amplifier