The invention relates to a method having application to combustion control of an internal-combustion engine for real-time estimation of engine combustion parameters from vibratory signals. A vibratory signal representative of the engine vibrations is continuously acquired as a function of the crank angle, from a vibration detector. Real-time filtering of this vibratory signal and real-time estimation of the Fourier decomposition coefficients for the acquired vibratory signal is carried out by inverting the dynamics of the filter which is used. Finally, real-time estimation of combustion parameters allowing the combustion to be qualified is carried out from these coefficients.

1. Field of the Invention
The present invention relates to a method for real-time estimation of combustion parameters of an internal-combustion engine from the vibratory response of the engine delivered by a vibration detector (accelerometer).
2. Description of the Prior Art
Standards for emission reduction have led to a progressive adaptation of engine technologies such as the introduction of additional actuators (exhaust gas recirculation valves, direct electronic injection and variable-geometry turbines) and new combustion modes (homogeneous diesel combustion or stratified gasoline combustion). In this context, the engine has become an assembly of complex systems requiring management by means of modern automation techniques. The engine control function manages the available actuators to guarantee engine performance while meeting environmental constraints. A fundamental aspect of engine control lies in the combustion control system via precise management of the thermodynamic conditions in the cylinders (temperature, boost pressure, composition of the mixture admitted) and of the adjustment of the injection parameters.
The new combustion modes, such as homogeneous diesel combustion, are much less polluting than conventional combustions (gasoline or diesel), but they are, on the other hand, much more sensitive. They therefore involve an additional investment in terms of regulation. Loop combustion control is possible only if information is available on the combustion progress and if it can be influenced through the control of the available actuators. These parameters can be obtained from direct measurement of the pressure in the combustion chamber by means of a specific detector. This method allows direct access to physical combustion parameters but, because of the life and cost of this type of detectors, they cannot yet be standard in vehicles. To date, it is more realistic to turn towards alternative techniques such as the estimation of combustion parameters from non-intrusive measurements. A synthesis of the existing methods is presented below:
Ionization current interpretation: The principle measures the ionization current generated during combustion. During combustion, some chemical reactions cause release of ions. Their production is influenced by the temperature and pressure conditions in the cylinder. To detect them, the plug is permanently supplied with a low-amplitude voltage. The ionization current contains information on the successive combustion stages: ignition, flame front propagation and a stage associated with the pressure and temperature variations at the end of the reaction. Eriksson and Nielsen have shown in the document mentioned below, for example, that the maximum pressure during a cycle and its argument can be identified by interpreting the ionization current:    L. Eriksson, Spark Advance Modeling and Control, Ph.D. thesis, Linköping University, Sweden, 1999.
Analysis of the instantaneous rotating speed of the crankshaft: The speed is measured by means of an encoder mounted at one end of the crankshaft. The cylinder pressure is reconstructed by inversion of the kinematic chain of the engine, the model thereof being of course known. The following document can be referred to for example:    S. J. Citron, J. E. O'Higgins & L. Y. Chen, Cylinder by Cylinder Engine Pressure and Pressure Torque Waveform Determination Utilizing Speed Fluctuations, SAE Paper (1989), No. 890486.
Reconstruction from engine vibration measurements: The vibrations of an internal-combustion engine can be measured by means of a detector, referred to as accelerometer, mounted on the engine. An accelerometer is a detector that, in a given reference system, measures the acceleration of the body to which it is fastened (or one of its components) and allows the resulting impacts and vibrations to be studied. Extraction of coherent combustion parameters from an accelerometer is difficult because of the nature of the signal that is delivered. In fact, this signal does not only contain information on combustion because the vibratory response of the engine is also due to other events, such as injection nozzle chattering, piston return stroke to the top dead center, vibrations induced by the distribution system, etc.
The use of accelerometer type detectors has already been described in previous books. The following documents, wherein the cylinder pressure is to be estimated from the signal delivered by the accelerometer, are exemplary:    Y. Gao & R. B. Randall, Reconstruction of Diesel Engine Cylinder Pressure Using a Time Domain Smoothing Technique, Mechanical Systems and Signal Processing 13 (1999), no. 5, 709-722,    H. Du, L. Zhang & X. Shi, Reconstructing Cylinder Pressure from Vibration Signals Based on Radial Basis Function Networks, Proceedings of the Institution of Mechanical Engineers, Part D 215 (2001), 761-767,    R. Johnsson, Cylinder Pressure Reconstruction Based on Complex Radial Basis Function from Vibration and Speed Signals. Mechanical Systems and Signal Processing, 2006.
Du et al. address with the cylinder pressure estimation problem by means of signal processing techniques involving deconvolution or inverse filtering. They have shown the capacity of a neural network to carry out an approximation of the non-linear transfer function between the evolution of the cylinder pressure and the generated vibratory signal. Johnsson uses a similar method according to which the signal delivered by the accelerometer is combined with the engine speed signal to reconstruct the pressure signal and the combustion parameters by means of a neural network whose inputs are imaginary variables.
Other methods using accelerometric detectors for controlling the combustion of an engine are also known:
EP Patent 1,116,946 describes a method and a system for controlling the combustion from signals delivered by an accelerometer, according to which the measured signal is windowed (combustion occurrence period). This signal is then processed during each control loop and it is compared with a reference signal in order to determine the changes to be made to the combustion parameters. Processing the signal from the accelerometer comprises three main stages: rectification, filtering and integration.
U.S. Pat. No. 2,004,267,430 (WO-05,001,263) describes a method of processing accelerometric signals resulting from the vibrations of an internal-combustion engine. In particular, the signals are filtered by spectral filters and the combustion analysis curve is reconstructed by deconvolution of a transfer function identified from an experimental database. The result is an estimation of the combustion parameters allowing combustion control. For example, the parameter referred to as SoC (Start of Combustion) is estimated from a polynomial depending on the energy release, its maximum angle and the boost pressure.
German Patent 19,536,110 (French Patent 2,739,414) describes a method of processing accelerometric signals resulting from vibrations for controlling the combustion of a diesel engine. In particular, the signals are filtered in two different frequency bands. The first frequency band [10 kHz, 30 kHz] allows extraction of components associated with the injection by means of a thresholding device. The second frequency band [0.5 kHz, 4 kHz] allows extraction of the signal components generated by the combustion using an identical thresholding method.
French Patent 2,834,789 describes a knock signal processing method. The method adjusts the acquisition sampling frequency to the engine speed. The Fourier transform is calculated for the various sampling value groups for a frequency of interest. The information on the combustion results from the summation of the Fourier transform results.
The parameters from the aforementioned approaches cannot be used directly for applications linked with internal-combustion engine diagnosis and control. These methods are based on a temporal integration of a signal delivered by an accelerometer. Processing of the signal from the accelerometer is not carried out in real time. Furthermore, these methods greatly depend on the nature of the combustion and/or on the technology of the detector used. Their field of application is therefore limited.
The present invention provides a method for controlling the combustion of an internal-combustion engine, regardless of the nature of the combustion and of the technology of the vibration detector that is used, from processing of the signal delivered by an accelerometer based on a real-time estimation of the harmonic decomposition of the accelerometric signal. The method provides real-time calculation of combustion state indicators.

Method for real-time estimation of engine combustion parameters from vibratory signals


Apparatus including water traps for containing pump gurgling noise within a washing machine are described. In one embodiment, tub outlet openings are formed in the washing machine tub bottom wall, and the apparatus includes an inlet in flow communication, and integral, with the tub water outlet. The pump inlet hose is coupled to the apparatus outlet so that the outlet is in flow communication with the water pump. The water trap is located between the apparatus inlet and outlet, and the water trap includes a u-shaped channel, a baffle extending from a lower surface of the tub bottom wall, and a standpipe. The u-shaped channel includes a water reservoir portion at an elevation below an end of the standpipe. In operation, water from the tub is discharged from the tub through the tub water outlets and into the apparatus. The water accumulates in the water reservoir portion, and if the amount of water discharged into the apparatus exceeds the volume of the water reservoir portion, the water spills over into the standpipe and is discharged from the apparatus through the outlet and into the pump inlet hose. Water discharged into the pump inlet hose is discharged from the washing machine by the water pump. The pump gurgling noise which may be generated as the pump oscillates between pumping water and air is substantially blocked by the water retained in the water trap.

Clothes washing machines typically include a drain pump for pumping water from the washing container, or tub, prior to beginning a spin cycle. The pump typically is located below the tub so that water drains, due to gravity forces, from the tub and into the pump. Draining the free water, i.e., water not absorbed in clothes located in the tub, from the tub prior to the spin cycle improves washing machine performance during the spin cycle by decreasing the occurrences and severity of out of balance loads.
Although draining the water from the tub before the spin cycle provides performance advantages, if the pump continues pumping operations after the tub is substantially empty of free water and before the spin cycle, a pump gurgling noise will be generated as the pump oscillates between pumping water and air. Once the basket begins to spin, water extracted from the clothes flows from the tub to the pump inlet and the pump gurgling noise temporarily stops. However, as the spin cycle proceeds, the amount of water extracted from the clothes will decrease and the pump will resume surging due to a lack of water at the pump inlet.
The pump gurgling noise may be annoying, particularly to occupants of a residence if the washing machine is located in a living area of the residence. It would be desirable to contain such gurgling noise within the washing machine, without adversely affecting the performance of the machine.
Known attempts to contain the gurgling noise include positioning a flapper valve over the tub water outlet. The flapper valve is biased so that water can flow from the tub to the pump but blocks flow from the pump toward the tub. In operation, once all the free water has been drained from the tub, the flapper valve closes and blocks the pump gurgling noise from the tub. Similarly, during the spin cycle, once the water has been extracted from the clothes in the tub, the flapper valve closes and again blocks the gurgling noise. By blocking the pump gurgling noise from the tub, the gurgling noise is substantially contained in the washing machine.
Although the flapper valve does facilitate containing the gurgling noise, the flapper valve is expensive to design and manufacture. Moreover, it is believed that with a flapper valve, lint can accumulate at the valve, thereby decreasing the pump out rate of water from the tub and trapping suds in the basket.
Another known device includes electrical sensors located in the tub so that once the water level within the tub falls below some predetermined level, the pump motor is deenergized. If the pump motor is deenergized before the water level falls to a level at which the pump begins to generate the gurgling noise, the gurgling noise can be eliminated. Such electrical sensors and controls, however, also add cost and complexity to the washing machine.
As explained above, it would be desirable to contain the pump gurgling within the washing machine. In addition, it would be desirable to provide such noise containment without substantially increasing the cost and complexity of the washing machine.


A semiconductor switch according to an embodiment of the invention includes resistive members connected with a source and a drain witch are n-type diffusion layers formed in a P-well of an n-type MOSFET. When a gate of the n-type MOFET is turned off, a positive voltage is applied to a node between the resistive members for a reverse bias at a PN junction between the source and the drain, and the well. When the gate is turned on, the node between the resistive members is set to 0 V.

1. Field of the Invention
The present invention relates to a semiconductor device suitable for a semiconductor switch for switching an RF signal.
2. Description of Related Art
Existing switches for an RF signal are given below. For example, a PIN diode is used as a single-function switch. Further, a compound semiconductor is mainly used as a multifunctional or high-performance semiconductor switch albeit expensive. It is easy to provide greater functionality to a switch made up of an enhancement type nMOS transistor on an inexpensive Si substrate. However, the switch of this type has a disadvantage in that its performance, especially, isolation characteristic with high frequencies is inferior to that of the compound semiconductor and is required to improve its performance.
FIG. 6 is a circuit diagram showing a conventional switch made up of an enhancement type nMOSFET (hereinafter referred to as nMOSFET). Hereinafter, this semiconductor switch is referred to as Related Art 1. A source 121 and a drain 122 of an nMOSFET 100a are connected with an RF input terminal 111 and an RF output terminal 112, respectively. A capacitor 103 is connected between the source 121 and the RF input terminal 111 for cutting DC components. Likewise, a capacitor 104 is connected between the drain 122 and the RF output terminal 112 for cutting DC components. A backgate 125 of the nMOSFET is grounded. A gate terminal 120 is connected with a terminal for controlling on/off states of a switch (hereinafter referred to as control terminal) 114.
FIG. 7 is a sectional view of the nMOSFET. A diffusion layer 123 serving as a source of an n-type semiconductor and a diffusion layer 124 serving as a drain thereof are formed on the surface of a P-well 126 serving as a backgate of a p-type semiconductor. A gate oxide film 130 is formed above the P-well 126 and between the diffusion layer 123 as the source and the diffusion layer 124 as the drain, and a gate 129 is formed on the gate oxide film 130.
In this case, depletion layers 127 and 128 are formed at a PN junction between the diffusion layer 123 as the source and the P-well 126 and a PN junction between the diffusion layer 124 as the drain and the P-well 126, respectively. Thus, as shown in FIG. 8, in the nMOSFET, the depletion layers 127 and 128 at the PN junction define capacitances 107 and 108 between a source and a drain. Further, capacitances 109 and 110 are formed through the gate oxide film 130 between the source and the drain.
Now, an operational principle of the switch is described. In FIG. 6, when the switch is turned on, a positive voltage not lower than a threshold voltage VT is applied to the control terminal 114. As a result, the gate terminal 120 of the nMOSFET 100a is turned on. Then, an RF signal is output from the RF input terminal 111 to the RF output terminal 112 by way of the capacitor 103, the nMOSFET 100a, and the capacitor 104. When the switch is turned off, the control terminal 114 is set to 0 V. Thus, the transmission of the RF signal through the nMOSFET 100a is controlled by turning off the gate terminal 120 of the nMOSFET 100a.
Incidentally, as an example of the semiconductor switch, there is an SPST (Single Pole Single Throw) switch that incorporates a shunt circuit and a controlling inverter. FIG. 9 is a circuit diagram showing another conventional semiconductor switch (hereinafter referred to as Related Art 2). The semiconductor switch of this type is disclosed in Japanese Unexamined Patent Application Publication No. 2003-347553, for example.
The circuit includes a switching nMOSFET 100b provided between the RF input terminal 111 and the RF output terminal 112 as well as a shunt nMOSFET 200 provided between the RF output terminal 112 and a ground terminal 118. A control signal for switching between the switching nMOSFET 100b and the shunt nMOSFET 200 is input from the control terminal 114. The control terminal 114 is directly connected with the gate terminal 120 of the switching nMOSFET 100b as in the above case. On the other hand, the control terminal 114 is connected with a gate terminal 250 of the shunt nMOSFET 200 through an inverter 140. Incidentally, when the shunt nMOSFET 200 is turned on, an impedance is set much lower than an impedance of the output terminal 112 (for example, 50 Ω). In addition, the capacitors 103 and 104 for cutting DC components are inserted between the nMOSFET 100b and the RF input terminal 111 and between the nMOSFET 100b and the RF output terminal 112, respectively. A capacitor 105 for cutting DC components is inserted between the shunt nMOSFET 200 and the ground terminal 18.
An operation of the conventional semiconductor switch is described hereinbelow. When the switch is turned off, the control terminal 114 is set to 0 V, and the switching nMOSFET 100b is turned off. At this time, the inverter 140 applies a positive voltage to the gate of the shunt nMOSFET 200 to turn the shunt nMOSFET 200 on.
However, the inventors of this application find the following problems. That is, in the semiconductor switch of Related Art 1, when the switch is turned off, the control terminal 114 is set to 0 V to turn off the gate terminal 120 of the nMOSFET 100a. At this time, as shown in FIG. 8, the capacitances 107 to 110 are formed between the source and the drain. Therefore, the RF signal is unintentionally transmitted through these capacitances. In particular, the depletion layer capacitances 107 and 108 at the PN junction are generally larger than the gate oxide film capacitances 109 and 110 by one order or more, and become big factors behind the leakage of the signal. That is, the nMOSFET 100a of Related Art 1 has a problem in that the input RF signals are not completely blocked and are partially transmitted through the switching nMOSFET 100a.
In contrast, in the nMOSFET 100b of Related Art 2, the impedance of the shunt nMOSFET 200 is much lower than the impedance of the switching nMOSFET 100b. Hence, the RF signals are mainly transmitted toward the ground terminal 118. Accordingly, the switch including such a shunt circuit can suppress the leakage of the signal to the RF output terminal 112.
However, if a positive voltage is applied to the control terminal 114 when the switch is turned on, the switching nMOSFET 100b is conversely turned on. Then, the shunt nMOSFET 200 is turned off since the gate terminal 250 is set at 0 V. At this time, the input signals are output to the RF output terminal 112 and also leak through the shunt nMOSFET 200 in an off state, leading to a problem in that the output signals are reduced.


A single side band modulation device includes a first Mach Zehnder interferometer and a second Mach Zehnder interferometer. The first Mach Zehnder interferometer includes at least two output arms, and the second Mach Zehnder interferometer includes at least two output arms. Terminals of the output arms are connected with one another.

1. Field of the Invention
The present invention generally relates to a single side band modulation device for single side band transmission, and in particular, to a single side band modulation device capable of simultaneously transmitting carrier channels.
2. Description of the Related Art
The spectrum of a modulated signal obtained by modulating amplitude-modulated data to a carrier forms an upper side band and a lower side band with respect to a carrier frequency serving as an axis of symmetry. For transmission of the modulated signal, single side band transmission is used where the carrier and one of those side bands are removed and only the other one is used.
The upper side band is a high frequency band to which the channels of the modulated signal are shifted and the lower side band is a low frequency band to which the inverted channels of the modulated signal are shifted.
Single side band transmission requires a bandwidth that is one half that of double side band transmission. By not transmitting a carrier and a side band, amplifier power consumption is minimized. In addition, single side band transmission reduces noise due to its narrow bandwidth, thereby improving a signal-to-noise ratio and reception sensibility. A single side band modulation device for single side band transmission filters in an optical domain using an optical fiber Bragg grating. However, the single side band modulation device is not suitable for actual use due to the difficulty in manufacturing the optical fiber Bragg grating and its poor stability. To solve the problem of the existing single side band modulation device, a LiNbO3-based single side band modulation device having superior stability is suggested.
FIG. 1 illustrates a conventional single side band modulation device 100 for single side band transmission. Referring to FIG. 1, the single side band modulation device 100 includes a single side band modulation module 120, a hybrid coupler 130, and a light source 110. The light source 110 generates carriers. The hybrid coupler 130 processes input data into a first signal having a phase of 0° and a second signal having a phase of 90° and outputs the first signal and the second signal to the single side band modulation device 120.
FIG. 2 illustrates the single side band modulation module 120 illustrated in FIG. 1. Referring to FIG. 2, the single side band modulation module 120 includes first through fifth phase modulators 121a, 121b, 122a, 122b, and 123. The first phase modulator 121a and the second phase modulator 121b constitute a first Mach Zehnder interferometer 121, and the third phase modulator 122a and the fourth phase modulator 122b constitute a second Mach Zehnder interferometer 122. The first signal and the second signal are input to each of the first Mach Zehnder interferometer 121 and the second Mach Zehnder interferometer 122 from the hybrid coupler 130 in a push-pull manner.
The first Mach Zehnder interferometer 121 generates a third signal by mixing the first signal and the second signal that are push-pull input from the hybrid coupler 130 and the second Mach Zehnder interferometer 122 generates a fourth signal by mixing the first signal and the second signal. The first through fourth signals have phase differences of 0 and π by bias voltages applied to the first through fifth phase modulators 121a, 121b, 122a, 122b, and 123. In particular, the phase of the third signal is +π/2 or −π/12 shifted by the fifth phase modulator 123.
FIGS. 3A through 3G are graphs illustrating changes in the phases of the first signal and the second signal in the single side band modulation module 120. The graphs show changes in the arrangement of a Bessel function with respect to the changes in the phases of the first signal and the second signal in each component of the single side band modulation module 120 when cos(ωt) is input to the hybrid coupler 130. J in graphs (a) through (g), i.e., FIGS. 3A to 3G, indicates a first kind Bessel function. Subscripts 0, 1, 2, 3 of J indicate the orders of the Bessel function. In other words, J0(x) is a first kind zero-order Bessel function, J1(x) is a first kind first-order Bessel function, J2(x) is a first kind second-order Bessel function, and J3(x) is a first kind third-order Bessel function.
The independent variable x is determined by a voltage applied to the single side band modulation module 120 and an inherent switching voltage of the single side band modulation module 120 (a voltage that should be applied for 180° phase shift). As the order of a first kind Bessel function increases with respect to the same factor x, the magnitude of the first kind Bessel function decreases. Thus, first kind Bessel functions whose orders are greater than 3 will be omitted. In FIG. 3, the size of an arrow indicates the magnitude of the first kind Bessel function and the direction of an arrow indicates a phase. In other words, when the Y-axis direction is assumed to be a phase of 0, the X-axis direction indicates a phase of π/2, the −Y-axis direction indicates a phase of π, and the −X-axis direction indicates a phase of 3π/2. The Z-axis indicates a frequency. With respect to the J0 carrier frequency, the frequency ±ω is applied to result in J1, the frequency ±2ω (which is 2 times the applied frequency) is used to result in J2, and a frequency ±3ω (which is 3 times the applied frequency) is used to result in J3.
The graphs (a) and (b) respectively show the waveforms of the first signal and the second signal that are push-pull input to the first Mach Zehnder interferometer 121, the graphs (c) and (d) respectively show the waveforms of the first and second signals that are push-pull input to the second Mach Zehnder interferometer 122, and the graph (e) shows the waveform of the third signal obtained by mixing the first signal and the second signal to the first Mach Zehnder interferometer 121. The third signal is mixed with the waveform of the fourth signal shown in the graph (f) after being ±π/2 phase-modulated by the fifth phase modulator 123.
When the third signal is +π/2 phase-modulated, it is mixed with the fourth signal to form an upper side band (USB) signal. When the third signal is −π/2 phase-modulated, it is mixed with the fourth signal to form a lower side band (LSB) signal. The resulting USB and LSB signals are represented in graph (g).
However, it can be seen from the graph (g) that a carrier frequency is removed from both the upper side band signal and the lower side band signal. Referring to FIGS. 4A, 4B, 4C, 4D showing changes in eye-diagrams with respect to the magnitude of a carrier frequency, it can be seen that the graph in FIG. 4A showing an eye-diagram with respect to a carrier frequency of the smallest magnitude is smallest and the graph in FIG. 4D showing an eye-diagram with respect to a carrier frequency of the largest magnitude is largest and represented clearly.
Modulation of a single side band from which a carrier frequency is removed cannot use a receiver of a direction detection type, but should use a complicated detector of an optical interferometer type instead.
To solve the problem, an offset may be applied to a conventional single side band modulation device. However, in this case, an unwanted other side band may be mixed. In other words, a lower side band signal may be mixed during transmission of an upper side band signal or the upper side band signal may be mixed during transmission of the lower side band signal.


The present invention is directed towards systems and methods for spillover threshold management in a multi-core system. A pool manager divides the spillover threshold limit of connections for vServers into an exclusive quota pool and a shared quota pool. Each vServer operating on a core is allocated an exclusive number of connections from the exclusive quota pool. If a vServer wishes to create connections beyond its exclusive number, the vServer can borrow from the shared quota pool. When the vServers are using at least a first predetermined threshold of their exclusive number of connections and the number of available connections in the shared quota pool has reached a second predetermined threshold, the multi-core system establishes a backup vServer.

As any server, virtual or physical, possesses finite capacity, the number of connections to a server over a network will be subject to inherent or imposed limits. In a single processor system, the processor may field all of these requests to create connections. The processor may process multiple connections in parallel according to the processor's own capacity. As the number of requests for service exhaust a processor's capacity, the system may establish a spillover system to service additional requests. In a multi-core system, requests to create connections may be handled by different cores at different times. Each of the cores may be running at different capacity. It is challenging to manage the connections across the different cores as the cores reach their capacity and require spillover support.

This patent is subject to a terminal disclaimer.

Systems and methods for spillover in a multi-core system


An electrical fuse structure is disclosed. The electrical fuse structure includes a fuse element disposed on surface of a semiconductor substrate, a cathode electrically connected to one end of the fuse element, and an anode electrically connected to another end of the fuse element. Specifically, a compressive stress layer is disposed on at least a portion of the fuse element.

1. Field of the Invention
The invention relates to an electrical fuse structure, and more particularly, to an electrical fuse structure with improved blowing window.
2. Description of the Prior Art
As semiconductor processes become smaller and more complex, semiconductor components are influenced by impurities more easily. If a single metal link, a diode, or a MOS is broken down, the whole chip will be unusable. To treat this problem, fuses can be selectively blown for increasing the yield of IC manufacturing.
In general, fused circuits are redundant circuits of an IC. When defects are found in the circuit, fuses can be selectively blown for repairing or replacing defective circuits. In addition, fuses provide the function of programming circuits for various customized functions. Fuses are classified into two categories based on their operation: thermal fuse and electrical fuse. Thermal fuses can be cut by lasers and be linked by laser repair. An electrical fuse utilizes electro-migration for both forming open circuits and for repairing. The electrical fuse for semiconductor devices may be classified into categories of poly electrical fuse, MOS capacitor anti-fuse, diffusion fuse, contact electrical fuse, contact anti-fuse, and the like.
A blowing mechanism of conventional electrical fuse is shown in FIG. 1. The cathode of an electrical fuse structure 1 is electrically connected to the drain of the transistor as a blowing device 2 (or referred to be as a driver) and. Voltages Vfs, Vg, and Vs are applied on the anode of the electrical fuse structure 1, the gate of the transistor, and the drain of the transistor, respectively. The source of the transistor is grounded. The electric current is traveled from the anode of the electrical fuse structure 1 to the cathode of the electrical fuse structure 1; and the electrons flow from the cathode of the electrical fuse structure 1 to the anode of the electrical fuse structure 1. The electric current suitable for the blowing is in a proper range. If the electric current is too low, the electron-migration is not completed, whereas if the current is too high, the electrical fuse tends to be thermally ruptured. In general, the blowing current for an electrical fuse structure made by a 65 nm manufacturing process is about 13 mA. The blown region of an electrical fuse also varies according to the design of the product. For instance, the blown region of a contact electrical fuse typically is located in the plug disposed on the cathode region, whereas the blown region of a poly electrical fuse is located in the polysilicon layer of the fuse element.
In conventional art, a predetermined voltage is typically calculated before the fuse structure is blown by voltage values above the predetermined voltage. Unfortunately, the aforementioned poly electrical fuses are unable to be blown by voltage values above the predetermined voltage while not exceeding the predetermined voltage by a lot, which ultimately produces poor blowing window. Therefore, how to fabricate a fuse structure with improved blowing voltage range has become an important task.


A discharge lamp includes a pair of electrodes for discharge and a discharge container having an inner space formed by quartz glass for separately placing the pair of electrodes and enclosing a discharge medium therein, a bulging part that surrounds the inner space, a pair of sealing parts that extend from ends of the bulging part and respectively support the pair of electrodes, an inner protective layer provided from a top portion opposed to a center of the pair of electrodes to a peripheral portion located at sides of the pair of sealing parts on an inner surface of the bulging part and having a thickness of the peripheral portion thinner than that of the top portion.

1. Technical Field
The present invention relates to a discharge lamp having a discharge container made of quartz glass, and a light source device and a projector using the same.
2. Related Art
For a light source device used in a projector, for example, a discharge lamp such as an ultra-high pressure mercury lamp is mainly used. For a discharge container forming the discharge lamp, high-purity quartz glass is often used. The high-purity quartz glass has high viscosity and unyielding properties. Further, the high-purity quartz glass is hard to be crystallized even at a high temperature and may secure sufficient light transmissivity in a certain period as the discharge container.
However, there has been a problem that, even in the case of using quartz glass, for use in a long time and a long period, it is finally crystallized (devitrified). Further, there has been another problem that, with the use in a long time and a long period, an electrode made of tungsten becomes thinner.
In order to solve the problems, an attempt to suppress crystallization of silica glass has been made by forming a boron oxide film on an inner surface of the discharge container (Patent Document 1 (JP-A-2010-198977)). However, according to this method, crystallization of the quartz glass may be suppressed to some degree, but, for example, the thinning of the tungsten electrode may not necessarily be suppressed. Further, containers using a thin film of cubic boron nitride (c-BN), a thin film of silicon boron nitride (SiBN), a protective film of yttrium oxide, or the like have been known (Patent Document 2 (JP-A-6-333535), Patent Document 3 (JP-A-9-147801), and Patent Document 4 (JP-A-2008-270074)), however, in the cases, chemical vapor deposition (CVD) has been used for all of them, and it has been difficult to form them thicker on the inner surfaces of the discharge containers.

Discharge lamp, light source device and projector


In certain embodiments, the present disclosure provides an anthropomorphic phantom for use with cryoneurolysis training. The anthropomorphic phantom having a body shaped to simulate a human anatomical structure. In some forms, the phantom body comprises a first material configured to simulate human soft tissue, a simulated nerve embedded within the first material, and a simulated fascial plane embedded within the first material superficial to the simulated nerve.

Cryoneurolysis works by applying targeted cold to a peripheral sensory nerve, forming a precise ice ball under the skin at or near the target nerve. This freezing of the nerve immediately prevents the nerve from sending pain signals, and does not significantly damage surrounding patient tissue structures. Thus, cryoanalgesia is a reversible inhibition of the signal carrying part of the nerve. The effect on the nerve is temporary, and provides pain relief until the nerve regenerates and function is restored.
In general, target nerves suitable for Cryoneurolysis are superficial and can be difficult to locate by traditional ultrasound techniques. Current ultrasound guided regional anesthesia simulators do not have the necessary landmarks to train targeting superficial nerves with a cryoneedle.
Previous Cryoneurolysis procedures were invasive, and used large complicated machines. In one example, a device having three needle tips was utilized to achieve sufficient ice formation. These prior devices are utilized to provide a field block, in conjunction with a traditional regional anesthesia nerve block. These techniques are time consuming; requiring 30-40 minutes and can have irregular outcomes due to factors such as patient body mass index (BMI) and degree of overlap of needle placement.
Prior ultrasound training simulation phantoms were designed only for traditional nerve blocks. A need therefore exists for improved Cryoneurolysis procedures as well as methods and systems for training such procedures.

Ultrasound guided training simulators for cryoneurolysis pain blocks


A governor system is provided for engine starter mechanisms to prevent a premature retracting movement of a single-direction rotatable clutch. The governor system is constructed with a reduced number of parts and such that a clutch does not suffer from the increased angular momentum as it rotates together with a governor weight. The governor system includes a casing or a bracket fixed to a driven gear, with the governor weight received in the casing. The governor weight is provided with a first and a second weight portion which are different in weight from each other such that the center of gravity of the governor weight is disposed radially eccentric. When the rotatable clutch rotates to advance and moves out of a receptacle hole of the governor weight, simultaneously the governor weight rotates to shift in one radially outward direction toward said first or heavier weight portion, the second or lighter weight portion enters into the retracting passage of an advanced inner clutch base portion, thereby preventing the rotatable clutch from retracting prematurely to the initial position.

1. Field of Invention
The present invention relates to a governor system for engine starters of automobiles and motorcycles.
More particularly, the present invention relates to an improved governor system which, with a simple construction, can reliably prevent undesirable premature retracting movement of the rotating clutch.
The present invention also relates to an improved governor system which, with a simple construction, permits reduction of impact to the clutch when it is brought into intermeshing engagement with the input gear of the engine.
2. Description of Related Art
There is one known governor system including the single-direction rotation clutch operatively connected to the motor driven gear shaft via a helical spline disposed on the gear shaft, in which the inner and outer clutch members rotate together with the rotation shaft to transmit rotation to the engine, and the clutch is moved forward along the helical spline by the angular momentum of the motor to thereby bring the pinion gear disposed at its front portion into intermeshing engagement with the ring gear provided at the engine for starting the same.
This known engine starter is provided with the governor system to prevent retracting movement of the pinion gear to prevent undesirable retracting movement of the one way rotation clutch during operation. The governor system includes a governor weight means disposed at the rear portion of the clutch such that the governor weight means moves forward as the clutch moves forward while rotating. Then at this forward position, the weight means is displaced radially outwards by the centrifugal force of the clutch rotation. Thus, the displaced weight means engages with a stepped portion of the open end of the governor casing or receptacle so as to be locked and prevented from retracting itself. This known mechanism is constructed such that the governor weight moves forward together with the clutch, and thus the engagement of the weight means against the clutch increases the total weight of the rotating mass, which consequently increases the angular momentum of the clutch. This increased momentum leads to an adversely increased impact upon the pinion gear and the ring gear when they intermesh with each other.
Japanese Examined Patent Publications Nos. 2-14547 and 3-75750 disclose a governor system having a weight means composed of a pair of separate arc shaped governor weight members rotatably supported respectively such that the center of gravity of the governor weight means is located eccentrically or off the rotation axis. In this arrangement, a heavier member of the weight means located at one radial side of the gear shaft moves outwardly due to the centrifugal force of the gear shaft rotation, thus causing the other member or lighter member at the opposite radial side of the shaft to move inwardly or toward the latter, thereby preventing the clutch from moving rearwardly in the axial direction to the retracted position.

Governor system for engine starter mechanism


Provided are isolated cellobiohydrolases comprising a modified Glycoside Hydrolase (GH) Family 7 catalytic domain, a GH Family 7 catalytic domain and a modified Family 1 carbohydrate binding module (CBM), or both a modified Family 7 catalytic domain and a modified Family 1 CBM. Such isolated cellobiohydrolases exhibit from 45% to about 99.9% amino acid sequence identity to amino acids 1-436 of SEQ ID NO: 1 or to amino acids 1-438 of SEQ ID NO: 2 and improved activity on process substrates. Also provided are genetic constructs and genetically modified microbes for expressing the isolated cellobiohydrolases, a process for producing the isolated cellobiohydrolases, cellulase enzyme mixtures comprising the isolated cellobiohydrolase and a process for hydrolyzing a cellulosic substrate with such cellulase enzyme mixtures.

Lignocellulosic feedstocks are a promising alternative to corn starch for the production of fuel ethanol. These raw materials are widely available, inexpensive and several studies have concluded that cellulosic ethanol generates close to zero greenhouse gas emissions.
However, these feedstocks are not easily broken down into their composite sugar molecules. Recalcitrance of lignocellulose can be partially overcome by physical and/or chemical pretreatment. An example of a chemical pretreatment is steam explosion in the presence of dilute sulfuric acid (U.S. Pat. No. 4,461,648). This process removes most of the hemicellulose, but there is little conversion of the cellulose to glucose. The pretreated material may then be hydrolyzed by cellulase enzymes.
The term cellulase broadly refers to enzymes that catalyze the hydrolysis of the beta-1,4-glucosidic bonds joining individual glucose units in the cellulose polymer. Cellulases belong to the larger group of glycosyl hydrolases (GHs) which are organized in families and clans based on structural homology (Davies and Henrissat, 1995, Structure 15:853; Carbohydrate Active Enzymes database, Cantarel et al., 2009, Nucleic Acids Res., 37:D233). An updated database of members of the over 100 families of GH enzymes may be found at URL: www.cazy.org/Glycoside-Hydrolases/html. GHs include enzymes that catalyze the hydrolysis of other oligo- and poly-saccharides (e.g. glucanases, xylanases, mannosidases, galactosidases, etc.).
The conversion of cellulose to glucose involves the synergistic actions of endoglucanases (E.C. 126.96.36.199), cellobiohydrolases (E.C. 126.96.36.199) and beta-glucosidases (E.C. 220.127.116.11) (Henrissat et al, 1994; Knowles et al., 1987; Lynd et al., 2002; Teeri, 1997; Wood and Garcia-Campayo, 1990; Zhang and Lynd, 2004). Endoglucanases hydrolyze accessible glycosidic bonds in the middle of the cellulose chain, while cellobiohydrolases processively release cellobiose from these chain ends. Beta-glucosidases hydrolyze cellobiose to glucose thus minimizing product inhibition of the cellobiohydrolases and endoglucanases.
Although cellulases drive hydrolysis of cellulose to glucose, additional enzymes have been discovered that enhance the efficiency of a cellulase system. These enzymes may include hemicellulases, which break down xylan and other hemicellulosic material in biomass (Maheshwari et al., 2000, Microbiol Mol Biol Rev. 64:461); swollenins and expansins, which rearrange the structure of cellulose (Saloheimo et al, 2002, Eur. J. Biochem. 269:4202; Sampedro and Cosgrove, 2005, Genome Biol. 6:242); and partially or uncharacterized activities such as the GH Family 61 enzymes (Harris et al., 2010, Biochemistry 49:3305) and the cellulose-induced proteins (CIPs—Foreman et al., 2003, J. Biol. Chem. 278:31988). High efficiency cellulase systems for the conversion of lignocellulosic substrates will incorporate any or all of these enzymes depending on the composition of the biomass and the process conditions (Henrissat et al., 1985, Bio/technology 3:722; Baker et al., 1998, Appl. Biochem. Biotechnol. 70-72:395; Boisset et al., 2001, Biotechnol. Bioeng. 72:339; Berlin et al., 2007, Biotechnol. Bioeng. 97:287; Gusakov et al., 2007, Biotechnol. Bioeng. 97:1028; WO2008/025165; WO2009/026722; Meyer et al., 2009, J. Cereal Sci. 50:337).
Cellulases—as well as other GH enzymes—share common gross structures and mechanisms of catalysis (Teeri et al., 1992, Biotechnology 21:417). All GH enzymes have a catalytic domain (CD) and the particular structure of this domain determines its GH Family designation, of which there are over 100. Two general catalytic mechanisms have been identified for GHs and all enzymes from a given family will have a common mechanism (McCarter and Withers, 1994, Curr. Opin. Struct. Biol. 4:885; Zechel and Withers, 2000, Acc. Chem. Res. 33:11). Retaining enzymes, which retain the anomeric configuration of the reducing end, hydrolyze by means of a double displacement reaction wherein the reducing side of the target linkage is first displaced and covalently attached to an acidic residue in the active site, followed by a second displacement, usually by water (though possibly by other hydroxyl-containing compounds including sugars) to complete the displacement (White and Rose, 1997, Curr. Op. Struct. Biol. 7:645). Inverting enzymes, which invert the configuration of the anomeric carbon, have an activated water to which the reducing end of the target linkage is directly displaced.
Cellulases, as well as many hemicellulases and enzymes accessory to cellulose hydrolysis, often have a carbohydrate binding module (CBM) also referred to as a cellulose binding domain (CBD) in the case of cellulases. One function of the CBM is to facilitate contact of the CD with the substrate. Some research suggests that certain CBMs may also disrupt cellulose structure and thus facilitate catalytic activity by the CD (Din et al., 1994, Proc. Natl. Acad. Sci. U.S.A. 91:11383; Teeri et al., 1992, Biotechnology 21:417). There are three general types of CBM represented in over 40 different families. Of these, Type I CBMs bind to the surface of crystalline cellulase; Family 1 CBMs belong to Type I and are the only type found in glycosyl hydrolases from filamentous fungi. Structurally, a CBM/CBD may be nearly contiguous with the CD, but usually these domains are connected by an unstructured, often glycosylated, linker peptide typically of 10 to 50 residues in length that may be involved in cellulose interactions (Srisodsuk et al., 1993, J. Biol. Chem. 268:20756).
The cellobiohydrolases are the primary drivers of cellulose hydrolysis. These enzymes bind to the free ends of cellulose chains and catalyze, often processively, the cleavage of cellobiose units from the chain ends. Thus, cellobiohydrolases catalyze the majority of reactions that release soluble oligosaccharides from the solid cellulose substrate and make them available for further hydrolysis to glucose. There are two major classes of CBH (Barr et al., 1996, Biochemistry 35:586). Cellobiohydrolase 2 (CBH2 or CBHII) enzymes are inverting enzymes that hydrolyze from the non-reducing end of the cellulose chain; most CBH2 enzymes are found in GH Family 6. Cellobiohydrolase 1 (CBH1 or CBHI) enzymes are retaining enzymes that hydrolyze from the reducing end of the cellulose chain; most CBH1 enzymes are found in GH Family 7. CBH-like enzyme activities exist in other GH Families (e.g. Family 9 and 48). The activities of, and synergy between, CBH1 and CBH2 accounts for a majority of total cellulase activity from most fungal systems.
Glycoside hydrolase enzymes comprising Family 7 CDs are found in eukaryotes, primarily fungi, and comprise both exo- and endo-glucanases. GH Family 7 enzymes are mostly cellulases, although chitosanase and xylanase activities have also been reported. The family is distinguished by a beta-jelly roll core structure, with much of the protein in random coil held together by disulfide bonds. Exoglucanases of this family, in contrast to endoglucanases, have peptide loops that cover the active site cleft, turning it into a closed tunnel that channels a cellulose chain past the active site residues and enables high processivity (Kleywegt et al., 1997, J Mol Biol. 272:383). The active site tunnel or cleft consists of a series of monomer (glucose in the case of cellulose) binding sites that associate with the polysaccharide chain by means of ring stacking interactions between the sugar residues and aromatic side chains in the cleft. In the case of cellulases, the bound cellulose is thus correctly aligned with two acidic residues at the active site which catalyze the double displacement hydrolysis. The monomer binding sites are numbered from the point of catalysis, with positive numbers proceeding in the direction of the reducing end of the cellulose chain, and negative numbers in the direction of the non-reducing end. Therefore, the catalytic site lies between +1 and −1 sites, and for the Cel7 cellobiohydrolases, the product binding site would be the +1 and +2 sites which would be occupied by cellobiose after the initial displacement (Divne et al., 1998, J. Mol. Biol. 275:309).
Cellulases and other GHs are produced by a wide range of organisms for a variety of natural purposes. Cellulases are predominantly enzymes secreted by micro-organisms—bacteria and fungi—to obtain nutrients from the environment. Bacteria often secret enzymes that are linked together in an extended, non-covalently associated structure called the cellulosome (Fontes and Gilbert, 2010, Annu Rev Biochem. 79:655). Fungi typically express individual enzymes, though some fungi, such as those living in the rumen of ruminant animals (e.g. sheep and cattle), can also form extended cellulosome-like structures (Ljungdahl, 2008, Ann. N.Y. Acad. Sci. 1125:308). The precise enzymes and enzyme ratios that an organism expresses will be determined by the substrates upon which they have evolved and the current substrate upon which they are growing. Expression of most cellulases and hemicellulases is induced by small molecules related to the target substrate (Schmoll and Kubicek, 2003, Acta Microbiol Immunol Hung. 50:125; Mach and Zeilinger, 2003, Appl Microbiol Biotechnol. 60:515).
The mesophilic fungus Trichoderma reesei (the anamorph of Hypocrea jecorina) and the thermophilic fungus Myceliophthora thermophila (the anamorph of Thielavia heterothallica) are major sources for industrially useful glycoside hydrolases. Both secrete large amounts of protein comprised mostly of hydrolytic enzymes, and for this reason are useful production hosts for industrial enzymes.
T. reesei secretes two GH Family 7 enzymes, CBH1 (Cel7A) and EG1 (Cel7B), of which the Cel7A is the major secreted protein product. The three-dimensional structures of the catalytic domains of both Cel7A and Cel7B have been solved (Divne, et al., 1998, J. Mol. Biol. 275: 309-325; Kleywegt et al., 1997, J. Biol. Chem. 272: 383-397) as have structures for several other Family 7 enzymes. M. thermophila secretes at least three GH Family 7 enzymes. Other industrially relevant cellulases come from fungi including, but are not limited to, species of Aspergillus, Chaetomium, Chrysosporium, Coprinus, Corynascus, Fomitopsis, Fusarium, Humicola, Magnaporthe, Melanocarpus, Myceliophthora, Neurospora, Phanerochaete, Podospora, Rhizomucor, Sporotrichum, Talaromyces, Thermoascus, Thermomyces and Thielavia.
GHs, particularly cellulases and hemicellulases, have many useful applications in industry. Cellulases are used in the textile industry for biopolishing, denim abrasion, and detergent applications (e.g. Anish et al., 2007, Biotechnol Bioeng. 96:48; Montazer et al., 2010, Appl Biochem Biotechnol. 160:2114; Shimonaka et al., 2006, Biosci Biotechnol Biochem. 70:1013). Glucanases and xylanases are used in the brewing and baking industries to reduce viscosity and improve product texture (e.g. Bai et al., 2010, Appl Microbiol Biotechnol. 87:251). Hemicellulases, particularly xylanases, are used in the pulp and paper industry to improve bleachability, improve process efficiency and modify paper quality and attributes (e.g. Suurnäkki et al., 1997, Adv Biochem Eng Biotechnol. 57:261). Finally, cellulases are being used to hydrolyze cellulose to sugars for fermentation to value added products, particularly biofuels and fuel grade ethanol (Dashtban et al., 2009, Int J Biol Sci. 5:578). Because GH Family 7 cellobiohydrolases are recognized as primary drivers of cellulose hydrolysis in cellulase enzyme systems, intense efforts have been made to improve these enzymes using the methods of modern molecular biology.
Targets for enzyme improvement depend upon the process conditions and the end goal of the enzyme application. Common improvement targets are thermostability and thermophilicity to enable enzymes to work at high process temperatures. Higher process temperatures are favored to increase reaction rates and decrease the likelihood of microbial contamination. Another common target is pH optimum and range, which may need to be aligned between enzyme and process. Reducing enzyme inhibition and inactivation by process-specific factors, including product inhibition, may be important for certain process configurations. Finally, increasing the specific activity of an enzyme under process conditions is always desirable. Targets for enzyme modification are far ranging and highly specific to the process and end goal. One general target may be broadening, narrowing, or changing the substrate specificity. Another general target might be limiting the stereochemistry of a reaction.
Many approaches have been developed to improve and/or modify the attributes of an enzyme. These run a gamut from rational design to directed evolution. For rational design, the structure/function relationship of the protein is carefully considered and conscious design changes are made based on an understanding of protein biochemistry (e.g. Wohlfahrt et al., 2003, Biochemistry 42:10095). For directed evolution, a library of enzyme variants comprising random changes throughout the amino acid sequence is made and the library is screened by means of an assay to identify improved/altered variants (Arnold and Moore, 1997, Adv Biochem Eng Biotechnol. 58:1; Kim et al., 2000, Appl Environ Microbiol. 66:788). A great many hybrid approaches also exist, sometimes referred to as "semi-rational" design. For example, it has been known for a long time that the consensus sequence of a protein family is often more stable than individual members (Lehmann et al., 2000, Biochim Biophys Acta. 1543:408; Lehmann and Wyss, 2001, Curr Opin Biotechnol. 12:371). Therefore, one approach to generating more stable enzymes is to mutate non-consensus residues to the consensus sequence. Another example is the SCHEMA approach involves the random swapping of structurally defined domains from several members of a common protein family and then screening for improved/altered variants by means of an assay (Silberg et al., 2004, Methods Enzymol. 388:35; Heinzelman et al., 2009, Proc Natl Acad Sci USA. 106:5610). A third example is the ProSar algorithm which uses information from initial random screens to design secondary and tertiary recombinants for screening (Fox et al., 2003, Protein Eng. 16:589).
GH Family 7 enzymes have been an area of intense investigation and development for commercial applications. For example, the Trichoderma Cel7A has been mutated by rational design to alter the pH optimum and thermostability of the enzyme (Becker et al., 2001, Biochem J. 356:19; Boer and Koivula, 2003, Eur J Biochem. 270:841). A Cel7A consensus sequence has been constructed and expressed, and shown to be more thermostable than the Trichoderma Cel7A enzyme (U.S. Publication No. 2005/0054039). The SCHEMA approach has been applied to create hybrid Cel7A enzymes of increased thermostability (Heinzelman et al., 2010, Protein Eng Des Sel. 23:871). Random mutagenesis has also been applied to identify improved Trichoderma Cel7A variants. Both rational design and directed evolution have been applied to improve the thermostability of Cel7B from Melanocarpus (Voutilainen et al., 2007, Enz Microb Technol. 41:234; Voutilainen et al., 2009, Appl Microbiol Biotechnol. 83:261). A similar rational design approach was applied to stabilize Cel7A from Talaromyces, and serendipitously improved the specific activity in one instance (Voutilainen et al., 2010, Protein Eng Des Sel. 23:69). The CBM of the Trichoderma Cel7A has been engineered to make binding to cellulose pH-sensitive and thus reversible under process conditions, enabling the possibility of enzyme recycling (Reinikainen et al., 1992, Proteins 14:475; Reinikainen et al., 1995, Proteins 22:392; Linder et al., 1999, FEBS Lett. 447:13). The KM of the Humicola Cel7 endoglucanase was lowered by rational design mutations that create an additional sugar monomer binding site (Davies et al., 1997, J Biotechnol. 57:91.
Well-designed assays are key to the successful identification of improved enzymes, particularly in the case of stochastic methods (e.g. directed evolution). Although soluble chromogenic and fluorogenic substrates have been developed for detecting the activity of GH enzymes and may be used in some screening assays, the performance of a GH enzyme on these artificial substrates often does not correlate to activity on a native or technical substrate such as cellulose or xylan. Instances where improvement on one substrate did not correlate to improvement on another have been documented (Teeri et al., 1998, Biochem Soc Trans. 26:173; Voutilainen et al., 2010, Protein Eng Des Sel. 23:69; Kura{hacek over (s)}in and Väljamäe, 2011, J Biol Chem. 286:169). Therefore, when screening for improved enzymes, it is critical to use process relevant substrates and conditions.
Variants of T. reesei (H. jecorina) Cel7A comprising a number of amino acid substitutions are disclosed in U.S. Pat. No. 7,951,570, U.S. Publication No. 2011/0229956, and U.S. Publication No. 2009/0075336. Variants of M. thermophile CBH1a comprising a number of amino acid substitutions are disclosed in U.S. Publication No. 2012/0003703. However, these variants were isolated by screening for improved thermostability or thermophilicity using soluble substrates rather than a cellulosic substrate. In some cases, the thermostable variants were subsequently characterized for their cellulose-hydrolyzing activity.
Here we present variants of T. reesei Cel7A isolated by screening for improved activity using process-relevant substrates under process-relevant conditions. Specific mutations conferring improvement were mapped to Cel7A cellobiohydrolases from other organisms to demonstrate that the improvements can be generalized to GH Family 7 enzymes.


A panel, for installation on a ceiling as a component of a matrix grid of similar panels, with the ceiling panels capable of being installed directly on sheetrock ceilings without the otherwise need for affixing a wooden structure to the sheetrock ceiling before affixing the ceiling panels.

The use of ceiling panels, particularly but not exclusively for decoration, is well known. Ceiling panels are typically composed of sheet metal with an embossed decorative pattern or of non-metallic material, such as asbestos or cellulose-like materials. The non-metallic ceiling panels have many deficiencies. Consequently metal ceiling panels, particularly those fabricated of tin, are preferred. However, the installation of metal ceiling panels presents challenges.
Most non-suspended ceilings are constructed of sheetrock. Traditionally metal ceiling panels have been installed, that is, affixed to the ceiling, by using nails at the corners or at the perimeter of each individual ceiling panel. However, due to the nature of the composition of sheetrock, nails cannot adequately affix metal ceiling panels to sheetrock due to the inability of nails to adequately grip and hold firmly to the sheetrock and the resultant tendency of the nails to slip-out of overhead sheetrock over a period of time, thereby releasing the panels from the ceiling, which of course is most undesirable.
Consequently, the traditional approach to installing metal ceiling panels to sheetrock ceilings is to first install a plywood surface over the entire sheetrock ceiling, and to then subsequently nail each of the metal ceiling panels into the thusly installed plywood. This is a labor intensive, time consuming and costly installation procedure.
An alternative but equally undesirable approach is to install wooden strips on the sheetrock ceiling, and to then nail each of the metal ceiling panels into the wood strips. With this approach, it is essential for the wood strips to be aligned very carefully to assure that the strips do in fact align with the edges of the panels as they are installed. Although easier than covering an entire sheetrock ceiling with plywood prior to installation of metal ceiling panels, this wooden strip approach is also still a very a labor intensive, time consuming and costly installation procedure.
In addition, metal ceiling panels traditionally have been installed by being placed side-by-side with each other, without any interlocking mechanism to attach adjoining ceiling panels to each other during the installation process, or indeed otherwise. Such interlocking of contiguous ceiling panels would both facilitate the installation process and would also enhance the structural integrity of the installed metal ceiling panel matrix grid.
The manual dexterity necessary to install ceiling panels overhead is tremendous; not only does the installer need to assure proper alignment of each panel, but that installer must simultaneously also hold and support the panel in an overhead position while handling nails and a hammer.
An objective of the present invention is to solve the aforesaid problems.

American Metal Ceiling Panel Manufacturing, Inc.


A method and apparatus for providing a three-dimensional (3D) image are provided. The method includes receiving a left-eye image and a right-eye image, estimating an overlap region of the left-eye image and right-eye image; generating an overlap image based on the estimated overlap region; and controlling the left-eye image, the right-eye image and the overlap image to be output.

1. Field
Apparatuses and methods consistent with the exemplary embodiments relate to a method and apparatus for providing a three-dimensional (3D) image, and more particularly to a method and apparatus for providing a 3D image, in which the 3D image that is passing through the 3D glasses and is focused on a user is increased in brightness.
2. Description of the Related Art
Technology for a 3D is applied to various fields such as image information and communication, broadcasting, medical treatment, education and training, military applications, a game, an animation, virtual reality, computer-aided design (CAD), industrial technology, etc., and is a core technology for the next generation 3D multimedia information communication required in common by these many fields.
Generally, a cubic effect perceived by a human is based on combination of a degree of change in the thickness of a crystalline lens in accordance with a position of an object to be observed, a difference in an angle between a pair of eyes and the object, a difference in a position and a shape of the object between the left and right eyes, a parallax due to movement of the object, and various effects owing to psychology and memory, etc.
Among them, a binocular disparity caused because two eyes of a human are away from each other by about 6˜7 cm in a horizontal direction is one of the most important factors in the cubic effect. That is, an object is viewed with a difference in an angle due to the binocular disparity, and this difference causes the eyes to have different images, respectively.
These two images are transmitted to the brain via the retina, and the brain perceives an original 3D image by combining the information from these two images exactly.
A 3D-image display apparatus is divided into a glasses type using special glasses, and a non-glasses type using no glasses. The glasses type includes a color filter type where images are separated and selected using color filters that complement each other, a polarizing filter type where a left eye image and a right eye image are separated using a lightproof effect based on combination of orthogonal polarizing devices, and a glasses shutter type where the left eye and the right eye are alternately shielded in response to a sync signal for projecting a left-eye video signal and a right-eye video signal to a screen.
The non-glasses type includes a parallax barrier type and a lenticular lens type.
The glasses type includes a passive type, an active type, and anaglyph type.
As the non-glasses type, the parallax barrier type and the lenticular lens type have been mostly used since they are convenient to be manufactured and easy to be realized. These two types are used by installing an optical plate such as the parallax barrier or the lenticular screen in a front or back of a display screen. Such types have a very narrow effective view and are available for only one person.
The glasses type is divided into a side-by-side type, a top and bottom type, a checker board type, and a sequential frame type, etc.
An apparatus for providing a 3D image encodes a 3D video signal and transmits a 3D display.
The 3D display is divided into a passive type and an active type in accordance with a method of reproducing the 3D video signal.
In the non-glasses type, a left-eye image and a right-eye image are displayed, and the left-eye image and the right-eye image are focused on a user's left and right eyes, respectively.
Since the left-eye image is focused on a user's left eye and the right-eye image is focused on a user's right eye in the non-glasses type, there may be no crosstalk between the left-eye image and the right-eye image.
In the glasses type, the left-eye image and the right-eye image are displayed in sequence, and the left-eye image and the right-eye image are respectively focused on a user's left and right eyes in accordance with synchronization for shutters of the 3D glasses.
In the glasses type, the left-eye image and the right-eye image displayed in sequence interfere with each other in accordance with synchronization for shutters of the 3D glasses, and therefore there may be crosstalk between the left-eye image and the right-eye image.
To prevent the crosstalk in the glasses type, a black image having no image is inserted between the left-eye image and the right-eye image.
The black image overlaps with the left-eye image and the right-eye image, so that each brightness of the left-eye image and the right-eye image can be decreased.

Method and apparatus for providing 3-dimensional image


The present invention relates to location/position-based context awareness for devices and mobile terminal devices, respectively. In particularly, the present invention relates to an infrastructure entity performing the location/position-based context awareness for a portable terminal device. According to the present invention an infrastructure entity and a method operable therewith for serving distance-dependent context information relating to a defined environment is provided. For instance, terminal/object distances are determined in accordance with a position of a portable terminal, each position of a plurality of objects and a position of an infrastructure entity, which is adapted to serve the aforementioned distance-dependent context information. Context information, which is associated with each of the plurality of object, is provided for being selected. Context information is selected from provided context information on the basis of the determined terminal/object distances. The selected context information is finally transmitted to the portable terminal for being processed thereon.

Today's portable terminal devices have limited input, output and storage capabilities, which directly limit the usability of such conventional portable terminal devices. Due to those limitations users are forced to handle such portable terminal device with more or less effort. Whereas the limitations in output and storage capabilities will be overcome by the implementation of currently available and future technical developments becoming standard, the limitation in the input capability is the most challenging task in the view of technical innovation and development. In particular, the overcoming of the limited input capability of the portable terminal devices is difficult due to the fact that the number of input means is bounded by dimension and weight of those terminal devices. Typically solutions, which are already developed for instance with respect to desktop terminal devices, cannot be migrated to the field of portable terminal devices due to the given boundaries of the portable terminal device such as those mentioned above.
Several concepts, which enable context awareness of portable terminal devices, are currently under development to simplify the handling of those devices having limited input capability. In principle, context awareness designates typically the tailoring of a user interface of a portable terminal device to currently present environmental conditions; i.e. the user interface of a portable terminal device can be automatically adapted to the environmental conditions by for example presenting available choices or choices possibly desired by the user.
Basically, two state of the art approaches for context awareness in the above-enlightened sense shall be presented. Portable terminal devices may implement context sensors such as position measuring sensors or other sensors for detecting physical context properties. On the basis of context information resulting from such sensors such portable terminal devices are able to react correspondingly. In the second approach several context providing (serving) entities distributed in the environment serve for providing context information to portable terminal devices adapted to acquire the context information therefrom; i.e. such portable terminal devices collect the context information and react thereto on the basis of an analysis of the collected context information.
Both presented approaches suffer from significant disadvantages relating to costs, scaling, flexibility and configurability. In detail, in accordance with the first approach, portable terminal devices implementing sensors for detecting and sensing context information requires supplementary information to be retrieved since the sensed information is typically not sufficient for an adequate reaction of such portable terminal devices. However, the retrieving of such supplementary information on the basis of the sensed context information is problematic or even impossible, when considering that all supplementary information should be stored centrally in view of usability aspects. The distributed provision of the context information as purposed with the second approach overcomes the disadvantage of the first approach, but the provision and the maintenance of context providing entities is expensive and elaborate. Moreover, the specific provision of context providing entities dedicated for predefined purposes lack in flexibility and configurability.

Position-based context awareness for mobile terminal device


Language interpretation for users includes a portable system for providing access to interpretation services, such as a prepaid, debit or credit card for the user. The prepaid card has a number of minutes of language interpretation service associated with it in addition to a number of minutes of telephone time. A telephone number to call is printed on the card for language interpretation services. Minutes or other unit of measure are deducted from the card as used for the interpretation. The cards are language specific, and the telephone number printed on the card is specific to a certain language. The service can be part of telephone service or more especially part of a mobile telephone service. The mobile telephone has a number of minutes of language interpretation service associated with it in addition to a number of minutes of telephone time. A telephone number is programmed to call the language interpretation services.

1. Field of the Invention
The present invention relates generally to offering language interpretation services. More specifically, the present invention relates to providing language interpretation services to users through the use of a portable access system.
2. Description of the Background Art
Many travelers find that a major obstacle in traveling abroad is communication in countries where they do not speak the native language.
Previous approaches have been made to provide interpretation services to travelers, however they are not always convenient. Many people purchase foreign language dictionaries for the purpose of interpretation when traveling abroad, however this approach is certainly awkward in attempting a conversation and quite time consuming to use. It also adds to what a traveler has to carry around on a daily basis. Electronic devices are also available that offer interpretation based on what is typed on a small keyboard. This too can be time consuming and is not always convenient.
There is a also a system which is known as Language Line Services™ (LLS). This does provide interpretation services over the phone to businesses and some persons who are set up with pre-authorized accounts and accessible from only the US, UK, Canada and Japan. If used by consumers and with a requirement from a broad range of countries, a credit card would be required, and the access time and approval of credit card terms inserts a delay which is often unacceptable. Moreover the credit card model for payment is not an optimum business model. It is thus limited in use and is not a prepaid service.
It is therefore an object of the present invention to provide a method for providing interpretation services to users generally, for instance travelers that is convenient and can be accessed in a very short time.

System and method for offering portable language interpretation services


A purge air flow passage structure has an air flow passage for ventilating the purge air, a separation space that is provided in the air flow passage and separates dust in the purge air therefrom, and a filter that is provided in the air flow passage, is positioned upstream of the separation space, and collects dust in the purge air. The filter includes two or more shielding parts each of which has a plurality of passing holes r slits arranged in the width direction of the filter. The shielding parts are successively arranged in the air flow passage to be separated from each other by a predetermined distance in the air flow direction. Each of the shielding parts includes a wall portion facing upstream that is positioned such that the wall portion is struck by the purge air that passed through the passing hole of the neighboring upstream shielding part.

1. Field of the Invention
The present invention relates to a purge air flow passage structure for supplying purge air to a surface of a light receiving part of an optical probe such as a radiation thermometer. Specifically, the present invention relates to a purge air flow passage structure that can effectively collects dust in purge air flowing in an air flow passage, and separates the dust from the purge air.
2. Description of the Related Art
In the case of the operation of a gas turbine engine, combustion air compressed by a compressor is mixed with fuel, and the combustion air including the fuel is combusted by a combustor to produce combustion gas. The combustion gas causes a turbine to rotate, generating engine driving force, that is, output torque.
According to such a gas turbine engine, temperature at a gas turbine entrance is raised so that performance of the gas turbine can be improved. However, when a temperature at the gas turbine entrance becomes higher than the tolerable temperature for the turbine blade, the turbine blade is damaged. For this reason, in order to suppress temperature raise of the turbine blade, engine control is performed to control temperature, or cooling structure for the turbine blade is adopted.
In terms of safety and service life of the engine, it is very important to perform monitoring to maintain: the condition (1) that temperature of the turbine blade does not become higher than a specified value; and/or the condition (2) that the cooling structure for the turbine blade normally function in the case of adopting the structure. A radiation thermometer 20 as shown in FIG. 1 is used to measure surface temperature of a turbine rotor blade. As shown in FIG. 1, the probe 1 of the radiation thermometer 20 is disposed at the turbine case 3 of the gas turbine. In FIG. 1, the reference numeral 21 designates a turbine stator blade, 22 the turbine rotor blade, and 23 combustion gas.
When dust or the like attaches to the surface of a light receiving part (lens or window) of the radiation thermometer probe 1, the temperature measurement cannot be normally performed. In addition, since the radiation thermometer is disposed at the turbine case, and the surface of the light receiving part of the radiation thermometer is exposed to combustion gas having high temperature, there is a possibility that the light receiving part is damaged, and the radiation thermometer is deprived of the temperature measurement function. For this problem, the purge air flow is brought to the surface of the light receiving part so that the dust can be prevented from attaching to the surface of the light receiving part, and further, the light receiving part can be protected from high-temperature combustion gas.
Compressed air extracted from a compressor is used as the purge air, but the purge air itself contains dust. If the flow of the purge air containing dust is brought to the surface of the light receiving part, the surface of the light receiving part becomes tainted by the dust of the purge air. Accordingly, it is necessary to remove the dust from the purge air before purging (cleaning) the surface of the light receiving part by using the purge air.
FIG. 2 shows a conventional example of a purge air cooling structure that has a function of removing dust from the purge air. In FIG. 2, the structure is partially cut out for understanding. In this drawing, the reference numeral 1 designates the probe of a radiation thermometer, 2 a lens (light receiving part), and 15 a nozzle. As shown in FIG. 2, a space for an air flow passage for purge air 9 is formed between the probe 1 of the radiation thermometer and the nozzle 15. The purge air 9 is supplied from the upstream air flow passage (at the right side in FIG. 2), and passes through a separation space formed near the outer edge of the lens attaching part where the lens 2 is attached. Thereafter, the flow of the purge air 9 is brought to the surface of the lens 2 so that the surface of the lens 2 can be purged by the purge air flow, and then, the purge air that was used to purge the lens 2 flows out to the turbine side. Specifically, in the separation space 8, the dust is separated from the purge air 9 by the inertia, the purge air 9 separated from the dust flows out from a penetration hole 7 at the upstream part in the separation space 8, and dust 10 flows out from a penetration hole 6 at the downstream part in the separation space 8 together with the purge air 9. The technique of purging the surface of the light receiving part by the purge air is disclosed in Japanese Laid-Open Patent Publication No. 11-96865.
However, even when the above-described separation space is provided, an effect of separating the dust from the purge air is not adequate, and it is difficult to completely separate the dust from the purge air. Thus, there is still a problem that the dust attaching to the surface of the light receiving part hinders temperature measurement.

Ishikawajima-Harima Heavy Industries Co., Ltd.


A method of producing an aromatic amino compound by using a primary or secondary amine compound having an aromatic ring group and a halogenated aromatic compound as starting materials, reacting the amine compound with the halogenated aromatic compound in the presence of a copper catalyst and a base so as to produce the aromatic amino compound having a structure in which an aromatic ring group derived from the halogenated aromatic compound is coupled to the amino group of the amine compound, wherein the amine compound and the halogenated aromatic compound are reacted together under a condition where an aromatic oxycarboxylic acid having a hydroxyl group and a hydroxycarbonyl group that are bonded to neighboring carbon atoms, is made present together with the copper catalyst and the base.

Aromatic amino compounds as represented by an arylamine and, particularly, a triarylamine and a diarylamine are useful as starting materials of medical and agricultural chemicals, as organic functional materials and as intermediate products therefor. In recent years, they have been used as organic EL materials and organic electrically conducting materials or intermediate products therefor, and are finding ever increasing importance.
As a method of synthesizing the triarylamine and the diarylamine, there has been known, for example, a method that reacts an aryl halide with a monoarylamine by using a copper catalyst. The above reaction has been called Ullmann reaction (see, for example, a non-patent document 1).
However, the Ullmann reaction requires a high reaction temperature and is accompanied by such defects that the obtained aromatic amino compounds (e.g., triarylamine and diarylamine) are colored conspicuously and that the yields are, usually, low due to the formation of by-products in large amounts. Besides, the obtained aromatic amino compounds must be refined requiring much work causing a defect of an increased cost of production.
In order to improve such defects, attempts have been made to lower the reaction temperature by adding a compound that can be coordinated in copper which is a reaction catalyst so that the object product can be obtained maintaining a high purity. For example, there have been reported methods capable of obtaining in high yields the object aromatic amino compounds through the reaction at such relatively low temperatures as 110 to 135° C. by adding a phenanthroline, a bipyridyl or a diamine compound such as cyclohexanediamine (see, for example, non-patent documents 2 to 4).
There has, further, been reported an example of conducting a reaction by adding a 1,1′-binaphthyl-2,2′-diol (see, for example, a non-patent document 5).
According to these examples, the reaction can be conducted under mild conditions and, besides, the object product can be obtained in good yields. However, the compound to be added is so expensive that there remains a problem from the standpoint of cost of production hindering the way toward putting the methods into practice.
There has, further, been known a method of conducting the reaction by increasing the basicity of the reaction system by adding a crown ether (see, for example, a patent document 1). However, the crown ether, too, is an expensive compound which makes the production method never advantageous from the standpoint of cost, and does not make the production method practicable.
There has, further, been known the Ullmann reaction for forming an alkylarylamine by reacting an alkylamine with an aryl halide in the presence of a copper catalyst, and there has been reported an example of the Ullmann reaction using an aromatic oxycarboxylic acid (concretely, a 2-hydroxybenzenecarboxylic acid) having a hydroxyl group and a hydroxycarbonyl group bonded to the neighboring carbon atoms thereof (see non-patent document 5). According to this example, however, the object product was not at all obtained, and no effect was recognized despite of using the aromatic oxycarboxylic acid.
There has, further, been proposed a method of producing an arylamine relying on the Buchwald-Hartwig reaction by using, as a catalyst, palladium-phosphine complex that has a trialkylphosphine as a ligand (see, for example, a patent document 2). According to this production method, however, the reaction must be conducted in a strictly controlled inert gas atmosphere to maintain activity of the palladium-phosphine complex. Besides, the trialkylphosphine itself which serves as a ligand is very unstable in the air, and must be stored and weighed in the inert gas atmosphere hindering the attempt for putting the method into practice. Besides, palladium is very expensive and the phosphine compound used as the ligand is expensive, too, making it difficult to place the method in practice.

Method of producing aromatic amino compounds


A structure, such as a fin or water sports board, including a core having opposed first and second core outer surfaces. The structure further includes first and second fiber sheets, wherein the first fiber sheet extends along the first core outer surface and the second fiber sheet extends along the second core outer surface. A thermoplastic material impregnates the first fiber sheet and the second fiber sheet and bonds the first fiber sheet and the second fiber sheet to the core. The thermoplastic material defines an outer surface of the structure.

Technical Field of the Invention
The present invention relates generally to a water sports board and fin, and more specifically to a water sports board and fin each being formed from a thermoplastic composite structure.
Description of the Related Art
Surfboards and other water sports boards are well known as recreational devices for use in oceans, as well as other bodies of water. Such boards are typically elongate, plank-like structures, which allow a user to stand or otherwise be supported on the board during the recreational activity. Most surfboards, and other water sports boards, usually include one or more fins coupled to the board for stability and control.
The construction of the boards and the corresponding fins has evolved greatly over the years. Along these lines, some of the first boards were formed from balsa wood, although major improvements over the years led to the boards being formed of a foam core with a laminate, such as fiberglass with a laminating resin covering and sealing the core. Using more modern board manufacturing techniques, the foam core may be initially molded into a "blank" in the rough shape of the board. The blank may then be worked on by a shaper who cuts, planes and sands the blank to prescribed specifications. Once the blank is properly shaped, the blank may be covered in one or more layers of fiberglass cloth and resin.
The fin(s) may be coupled to the board using a fin mount which is configured to allow the fin to be detachably secured to the board. In order to install the fin mount into the board, the fin mount is typically positioned into the foam core. A laminate may be placed over portions of the mount to secure the fin mount to the board.
Once the board is constructed and is used by the user, significant forces may be imparted on the board, fin and/or fin mount during such use. With regard to the fin, the forces imparted thereon may cause the fin to flex, and as such, the fin's ability to return to its normal state after having the force applied may affect the performance of the fin and the board as a whole.
Conventional construction techniques and manufacturing materials for boards, fins and fin boxes have resulted in boards, fins and fin boxes which have failed (e.g., broken) during use. For instance, it is not uncommon for a fin to break away from the board or for the board itself to snap into two pieces. Furthermore, conventional techniques for manufacturing boards and fins tend to be extremely labor intensive and harmful to the environment.
Therefore, there is a need in the art for an improved construction for the water sports board and the fin which has an improved strength and durability. Various aspects of the present invention address these particular needs, as will be discussed in more detail below.

Method of forming a thermoplastic fiber composite fin


A linear amplifier using a low frequency 2nd intermodulation feed-forwarding method to offset the 3rd intermodulation component of a fundamental signal is provided. This linear amplifier includes a transistor for amplifying the power of the fundamental signal, a first filter unit, one end of which is connected to the gate of the transistor, for filtering a 2nd order intermodulation signal from the fundamental signal, a low frequency amplifier connected to the other end of the first filter unit, for amplifying the 2nd order intermodulation signal with a predetermined voltage gain, and a second filter unit connected in series between the output port of the low frequency amplifier and the drain output port of the transistor, for filtering the amplified 2nd intermodulation signal and feeding the same to the output port of the transistor. This linear amplifier feeds the low frequency 2nd order intermodulation component of a fundamental signal forward to the output port of a power amplification transistor, thereby maintaining the stable characteristics of a circuit adopting a feed-forwarding method and favorably offsetting a 3rd intermodulation component that is adjacent to the frequency of the fundamental signal.

1. Field of the Invention
The present invention relates to a linear amplifier, and more particularly, to a linear amplifier using a low frequency 2nd order intermodulation feed-forwarding method.
2. Description of the Related Art
When a mobile terminal or a mobile base station power-amplifies and transmits a signal, the receiving sensitivity of a receiving side is degraded by distortion due to the interference between a fundamental signal to be transmitted and its intermodulation component.
In order to solve the above problem, conventional linear amplifiers shown in FIGS. 1A, 1B and 2 are used. Each of the conventional linear amplifiers roughly includes an input impedance matching unit (Zs) 20 for matching the output impedance of a signal source Vs with the input impedance of the input port of a transistor 12, 14 or 24, and an output impedance matching unit (ZL) 29 impedance-matching the output port of the transistor 12, 14 or 24 with an output load. An amplifier shown in FIG. 1A tunes to a distortion component signal using a source harmonic tuning method and reflects an intermodulation signal reflected by the gate of the transistor 12 back to the gate using a reflection coefficient control unit 17 having a variable capacitor or a stub at the gate port of the transistor 12, thereby offsetting a distortion component. In FIG. 1B, a reflection coefficient control unit 16 is installed to the rear of the transistor 14, and tunes a harmonic output from the rear of the transistor 14 and reflects the harmonic back to the gate using a load harmonic tuning method, thereby offsetting a 3rd order harmonic component.
FIG. 2 shows a linear amplifier using an intermodulation signal feed-backwarding method. The linear amplifier of FIG. 2 includes an amplification transistor 24, filters 25 and 28 for filtering a 2nd order harmonic component from an input signal, a phase shifting unit 26 for shifting the phase of the 2nd order harmonic component, and an amplifier 27 for amplifying the phase-shifted 2nd order harmonic component to a predetermined value. The phase-shifted 2nd order intermodulation signal is fed backward to the input port of the amplification transistor 24, thereby offsetting a 3rd order intermodulation component.
However, these conventional intermodulation signal tuning methods can offset only several dB of 3rd order harmonic component. In the intermodulation signal feed-backwarding method, 10 dB to 15 dB of intermodulation component can be offset, but the characteristics is unstable and the band is narrowed.
An objective of the present invention is to provide a linear amplifier using a low frequency 2nd order intermodulation feed-forwarding method for offsetting a 3rd intermodulation component while maintaining the stable characteristics of a linear amplification circuit obtained by feed-forwarding.
To achieve the above objective, the present invention provides a linear amplifier using a low frequency 2nd intermodulation feed-forwarding method to offset the 3rd intermodulation component of a fundamental signal, the device including: a transistor for amplifying the power of the fundamental signal; an input impedance matching unit connected to the gate of the transistor for impedance-matching a source of the received fundamental signal with the gate of the transistor; a first filter unit, one end of which is connected to the gate of the transistor, for filtering a 2nd order intermodulation signal from the fundamental signal; a low frequency amplifier connected to the other end of the first filter unit, for amplifying the 2nd order intermodulation signal with a predetermined voltage gain; a second filter unit connected in series between the output port of the low frequency amplifier and the drain output port of the transistor, for filtering the amplified 2nd intermodulation signal and feeding the same to the output port of the transistor; and an output impedance matching unit connected to the output port of the transistor for impedance-matching the output port of the transistor with an external load.
The voltage gain (xcex2) of the low frequency amplifier   -                              gm          3                ·                  C          0                            gmd        ·                  C          1                      .
The gm3 and gmd are the coefficients of terms vgs(t)3 and Vgs(t)vds(t), respectively, of Equation:
ids[vgs,vds]=gmxc2x7vgs(t)+gdxc2x7vgs(t)+gm2xc2x7
vgs(t)2+gmdxc2x7vgs(t)vds(t)+
gd2xc2x7vds(t)2+gm3xc2x7vgs(t)3+gm2dxc2x7
vgs(t)2xc2x7vds(t)+
gmd2xc2x7vgs(t)xc2x7vds(t)2+gd3xc2x7vds(t)3+. . .
which is a Taylor series extension formula of the drain-source non-linear current ids[vgs,vds] of the transistor.
Also, C0 and C1 in the voltage gain are the coefficients of the constant term and term vgs(t) in Equation Cgs[vgs(t)]=C0+C1xc2x7vgs(t)+C2xc2x7vgs(t)2+ . . . , which is a power series of a gate source capacitor of the transistor.

Linear amplifier using frequency 2nd order intermodulation feed-forwarding method

Pohang University of Science and Technology Foundation