Abstract: Disclosed herein is an apparatus that includes first and second signal lines; a first differential amplifier having an inverting input node receiving an input signal, a non-inverting input node receiving a reference potential, and an output node connected to the first signal line; a second differential amplifier having an inverting input node receiving the reference potential, a non-inverting input node receiving the input signal, and an output node connected to the second signal line; a level shift circuit cross-coupled to the first and second signal lines; a first replica circuit connected to the first signal line; a second replica circuit connected to the second signal line; and a first switch circuit configured to activate one of the level shift circuit, the first replica circuit, and the second replica circuit.

Abstract: A method of fabricating a transparent conductor includes the following steps. The first step is drawing a substrate from a first reel to a second reel along a travelling path, and along the travelling path. Next step is forming a metal nanowire dispersion layer on the substrate and then drying the metal nanowire dispersion layer to form a metal nanowire network layer. Next step is forming a matrix layer on the metal nanowire network layer so as to form a conductive layer of the metal nanowire network layer embedded in the matrix layer.

Abstract: Circuitry for voltage-to-current conversion, and in particular to differential voltage-to-current conversion circuitry. Such circuitry is operable to receive a differential voltage input signal and output a corresponding differential current signal. First and second controllable current sinks are connected to first and second load nodes of the circuitry so as to draw corresponding sink currents from those nodes.

Abstract: Current microphone designs are still using concepts developed in the early 20th century. A transducer followed by a simple buffer with high impedance, low power, and low gain. Even when tubes were replaced by solid state devices the same practice continued, with the low gain triode being replaced by an even smaller power, lower current FET buffer. The invention offers a microphone system intended for professional audio applications that dispenses with these, low power concepts and incorporates elements of a microphone, microphone pre amplifier, and high power mixing console/pre amp line drivers into a single housing. By combining transducer, high fidelity pre amp circuit, and high power line driving stage with a high voltage, high current external power supply, the capabilities of microphones can be greatly increased in many ways.

Abstract: The invention provides a grounding structure and a grounding method for a vacuum tube audio amplifier, the grounding structure and the grounding method including: with respect to a power source, utilizing a power circuit without a choke, an anti-coupling circuit, and a filament voltage regulator circuit; and with respect to the grounding method, utilizing an negative output terminal of an audio output transforming circuit or a negative terminal of a filter capacitor in the power circuit as a single ground terminal of the vacuum tube audio amplifier, and not arranging a grounding metal bottom plate therein, in order to achieve a compact, lightweight desktop model of a vacuum tube audio amplifier.

Abstract: A driver suitable for driving a power amplifier is provided. The driver includes a voltage buffer circuit and a voltage transforming circuit. The voltage buffer circuit receives an input signal, buffers the input signal, and outputs a first output signal. The voltage transforming circuit receives the first output signal and outputs a second output signal to the power amplifier, in which an equivalent inductance of the voltage transforming circuit and an input capacitance of the power amplifier are arranged to make the voltage buffer circuit have a voltage gain approximated to 1.

Abstract: An electronic amplifier delivers to a load an output signal related to an input, typically with increased power. As the power output, volume, or gain of the amplifier is changed, so may the spectral characteristics of the signal. In order to maintain the desired spectral or tonal character of the output signal over the dynamic range of output power, biasing of the amplifier must be adjusted. Particular ratios of drive and bias currents and/or voltages for different implementations of amplifier technologies should be relatively constant to produce substantially invariant input-output spectral relationships from low power output through high power output settings. Several techniques are presented which provide these relationship in amplifiers.

Abstract: A RF input signal system and method switches the RF input signal amplified by an amplifier PA1 or PA2 to be present only in great magnitude at the summing port of a hybrid combiner H2 when the SPDT switch SW1 is directing the “RF in” signal to the summing port of the hybrid divider H1, while the balancing port of H1 is terminated by the switch SW1. The benefit of switching between H and V ports by using this method eliminates the insertion losses of the switch SW1 and isolators ISO1 and ISO2 of the prior art. The benefit is also the speed of switching which can now be executed much faster (in nanoseconds) in comparison to the method shown in FIG. 1 where the limiting factor are the PIN diodes used in such devices (SW1 of FIG. 1) that only allows switching transients in tens of microseconds only. The non-summing port of H2 is then only radiating much less energy of ?20 to ?30 dB below that of the summing port.

Abstract: An apparatus for implementing a front end circuit for a transimpedance amplifier includes a front end core that receives an input signal from a photo diode. The front end core responsively generates a balanced output signal to downstream devices. A power supply provides a supply voltage to the front end circuit. In accordance with the present invention, a current source is located between the supply voltage the front end core to thereby isolate the front end core from disturbances on the power supply. This biasing arrangement advantageously provides an improved power supply rejection ratio for the front end circuit.

Abstract: A driver system comprises a direct current (DC) voltage source and a first bi-directional DC-to-DC converter having a primary side coupled to the DC voltage source and a secondary side and configured to convert a first voltage on the primary side to a second voltage on the secondary. The driver system also comprises a second bi-directional DC-to-DC converter having a primary side coupled to the DC voltage source and a secondary side coupled to the secondary side of the first bi-directional DC-to-DC converter and configured to convert the first voltage on the primary side to a third voltage on the secondary. The first and second bi-directional DC-to-DC converters are capable of boosting the first voltage, and the second control signal is a complement of the first control signal. A voltage difference between the second and third voltages comprises an output voltage that comprises an amplification of the first control signal.

Abstract: A low noise amplifier (LNA) with combined input matching, balun, and/or transmit/receive (T/R) switch is described. In one exemplary design, an apparatus includes a coupled inductor and an LNA. The coupled inductor receives a single-ended input signal, performs single-ended to differential conversion, and provides a differential input signal. The LNA receives and amplifies the differential input signal and provides a differential output signal. The coupled inductor includes magnetically coupled first and second coils. The first coil provides input impedance matching when the LNA is enabled. A resonator circuit formed with the first coil provides high input impedance when the LNA is disabled. A tuning capacitor coupled to the second coil provides amplitude imbalance tuning for the differential input signal. A transmit switch is coupled between the first coil and a transmitter.

Abstract: Aspects of a method and system for processing signals via an integrated low noise amplifier having a configurable input signaling mode are provided. In this regard, one or more circuits comprising an integrated amplifier may be configurable such that, in a first configuration, the one or more circuits are operable to handle a differential input signal, and, in a second mode of operation, the one or more circuits are operable to handle a single-ended input signal. The one or more circuits may output a differential signal when handling a differential input signal and when handling a single-ended input signal. In some instances, whether the one or more circuits are operable to handle a differential input signal or a single-ended input signal may determined by an inductance of a bond wire coupling the integrated amplifier to an integrated circuit package.

Abstract: An audio processing circuit is provided, receiving a microphone signal from a microphone to output a differential signal. A preamplifier receives the microphone signal to output a first preamplified voltage and a second preamplified voltage. A gain stage receives the first preamplified voltage and the second preamplified voltage to output the differential signal comprising a first differential output and a second differential output. In the preamplifier, a first operational amplifier is provided. A first voltage controlled current source is controlled by the output end of the first operational amplifier to provide a first current. A first transistor has a gate coupled to a ground voltage supply, a source coupled to the first voltage controlled current source for receiving the first current, and a drain coupled to a voltage ground. Likewise, a second voltage controlled current source and a second transistor are presented symmetrically to render the differential output.

Abstract: There is provided a power amplifier that can reduce power consumption by selectively turning a plurality of amplifiers on or off according to the power of a signal to be transmitted. A power amplifier according to an aspect of the invention may include: a first amplification section amplifying an input signal by a predetermined gain; a second amplification section having a plurality of amplification units re-amplifying the input signal, amplified by the first amplification section, by predetermined gains; and a switch section supplying or cutting off power to the plurality of amplification units according to an switching signal to selectively operate the plurality of amplification units.

Abstract: A balun amplifier is provided, which includes two input terminals, two output terminals and two modules. The first and the second input terminals receive a single-ended input signal, respectively. The first and the second output terminals provide a differential output signal. The first module is coupled to the first input terminal, the first output terminal, and the second output terminal. The second module is coupled to the second input terminal, the first output terminal, and the second output terminal. The first and the second modules receive the single-ended input signal through the first and the second input terminals respectively, amplify the single-ended input signal respectively, and convert the single-ended input signal into the differential output signal. The circuit topologies of the first and the second modules are symmetric except that types of transistors in the first and the second modules are different.

Abstract: A wideband low-noise amplifier includes a source-degenerated common-source amplifier, a common-gate amplifier, and a matching frequency band determiner. The source-degenerated common-source amplifier is configured to amplify an input signal to output a first signal that is opposite in phase to the input signal. The common-gate amplifier is connected in parallel to the source-degenerated common-source amplifier to amplify the input signal to output a second signal that has the same phase as the input signal. The matching frequency band determiner is configured to isolate an input terminal of the source-degenerated common-source amplifier and an input terminal of the common-gate amplifier and determine a matching frequency band.

Abstract: An amplifier provided according to an aspect of the present invention includes a set of passive impedances forming a tuned load to a gain stage and also to provide a 180 degrees phase shifted signal of a gain signal received from the gain stage. The output of the gain stage and the 180 degrees phase shifted signal together form a differential amplified signal corresponding to an input signal gained by the gain stage. In an embodiment, the set of passive impedances includes a three terminal centre tapped inductor in combination with a capacitor, together operating as a filter to pass only a desired frequency band. The windings of the inductor may be designed to provide mutual coupling between two portions such that there is a negative correlation between the strength of the received gained signal and the 180 degree phase shifted signal.

Abstract: The invention relates to a receiver (1) comprising an amplifier (31-34) for amplifying an antenna signal, which amplifier (31-34) comprises an amplifier input (11a) and an amplifier output (12a,12b), the amplifier input (11a) being a single ended input for receiving the antenna signal, the amplifier output (12a, 12b) being a differential output, and the amplifier (31-34) comprising circuit (41,42) for reducing a common mode input impedance of the amplifier (31-34).

Abstract: A high-efficiency single-to-differential amplifier has a first transistor acting as a first amplification stage. A second transistor, a third transistor, a first choke, a second choke, and a first capacitor form a second single-to-differential amplification stage. The first amplification stage receives and amplifies an input signal, outputs the amplified signal to the second single-to-differential amplification stage through a coupling module, and concurrently provides DC bias current to the second single-to-differential amplification stage through a tank. The second single-to-differential amplification stage reuses DC current of the first amplification stage, amplifies the output signal of the first amplification stage, and transfers it to a differential output.

Abstract: Aspects of a method and system for a low power fully differential noise canceling low noise amplifier (NC LNA) are provided. The NC LNA may receive signals via a single ended input and may generate an amplified symmetric differential output from the received signals. The NC LNA may utilize capacitor dividers, such as a capacitor bank, in the single ended input in order to provide impedance transformation that enables low power operation and matching to an input port. The NC LNA may generate one portion of the amplified symmetric differential output via a voltage divider, which may comprise a plurality of capacitors, such as a capacitor bank. The NC LNA may be implemented utilizing one or more circuits.

Abstract: An apparatus amplifies RF signals in a communication system by using a first directional coupler having at least two inputs and at least two outputs; at least two RF amplifiers, where an input of each RF amplifier is connected to a different one of the at least two outputs of the first directional coupler; and a second directional coupler having at least two inputs and at least two outputs, where each one of the at least two inputs is connected to an output of a different one of the at least two RF amplifiers. The at least two outputs of the second directional coupler are connected to at least two antennas, respectively.

Abstract: There is described a two-channel method for determining at least one output signal from variable input signals of sent by a transmitter, using two independent channels and consisting in alternately guiding the in put signals to said channels, wherein a multiplexer is used for switching said channels. A microprocessor contained in said channels delivers input test signals transmitted to the channel not currently receiving any variable input signal. Said channel transmits output signals compared with an expected value in order to verify the channel correct operation. Simultaneously, the other channel produces an output signal. Afterwards, the multiplexer switches a control signal.

Abstract: A circuit and method of reducing noise in the circuit comprises a first transistor and an amplifier operatively connected to the first transistor, wherein the amplifier comprises a plurality of transistors and is adapted to amplify an input signal, and wherein the input signal is differentially captured at an output of the first transistor and the amplifier. Preferably, the plurality of transistors comprises a second transistor and a third transistor. Furthermore, a noise level of the first transistor and the third transistor are preferably cancelled. The size of the second transistor may be approximately 1/50?. Preferably, a gain on an amplifier stage formed by the second transistor and the third transistor is adapted to be increased. Moreover, an equivalent transconductance of the amplifier is preferably independent of an impedance matching on the amplifier. Preferably, a noise figure level of the circuit is less than approximately 1 dB.

Abstract: A transceiver front end includes a transmit/receive (T/R) switch, a first balun, a second balun, a low noise amplifier, a power amplifier, and compensation circuitry. The T/R switch is operably coupled to an antenna for receiving inbound radio frequency (RF) signals and for transmitting outbound RF signals. The first balun includes a single ended winding and a differential winding, where the single ended winding is operably coupled to the T/R switch. The second balun includes a single ended winding and a differential winding, where the single ended winding is operably coupled to the T/R switch. The low noise amplifier is operably coupled the differential winding of the first balun. The power amplifier is operably coupled to the differential winding of the second balun. The compensation circuitry is operably coupled to the first balun to compensate for at least one of phase imbalance, amplitude imbalance, and impedance imbalance of the first balun.

Abstract: Provided is a circuit to perform single-ended to differential conversion while providing common-mode voltage control. The circuit includes a converter to convert a single-ended signal to a differential signal and a stabilizing circuit adapted to receive the differential signal. The stabilizing circuit includes a sensor configured to sense a common-mode voltage level of the differential signal and a comparator having an output port coupled to the converter. The comparator is configured to compare the differential signal common-mode voltage level with a reference signal common-mode voltage level and produce an adjusting signal based upon the comparison. The adjusting signal is applied to the converter via the output port and is operative to adjust a subsequent common-mode voltage level of the differential signal.

Abstract: An RF circuit configured to inteface a balanced port (1, 2, 11, 12) with an unbalanced port (4, 14) by emulating the function of a balun. Reactive components (20, 30, 120, 130) in both branches of a balanced circuit form two resonant circuits by resonating with parasitic reactance. At a predetermined operating centre frequency, one of the two resonant circuits is above resonance and the other is below resonance, resulting in a 180° phase difference between the signals delivered by the two branches. When used to interface an unbalanced signal source (10) to a balanced load (40), the input impedance may be set to a real value matching the output impedance of the signal source by selection of the reactive component (20, 30) values.

Abstract: Provided is a circuit to perform single-ended to differential conversion while providing common-mode voltage control. The circuit includes a converter to convert a single-ended signal to a differential signal and a stabilizing circuit adapted to receive the differential signal. The stabilizing circuit includes a sensor configured to sense a common-mode voltage level of the differential signal and a comparator having an output port coupled to the converter. The comparator is configured to compare the differential signal common-mode voltage level with a reference signal common-mode voltage level and produce an adjusting signal based upon the comparison. The adjusting signal is applied to the converter via the output port and is operative to adjust a subsequent common-mode voltage level of the differential signal.

Abstract: A circuit interfacing a balanced RF power amplifier with unbalanced load has a first shunt inductor and a series capacitor connected to a first output and a first shunt capacitor and series inductor connected to a second output of amplifier. The circuit comprises a second shunt inductor connected to the second output and feeding current to the second output. The first shunt capacitor may correspond to a sum of capacitors required to resonate with the series inductor and second shunt inductor. The second shunt inductor may exceed a value required to resonate with the capacitance of the first shunt capacitor less the capacitance required to resonate with the series inductor, by the same amount as the first shunt inductor exceeds the value required to resonate with the series capacitor. The circuit may further comprise a second shunt capacitor connected to first output, whereby first shunt capacitor exceeds sum of capacitors required to resonate with series inductor and second shunt inductor.

Abstract: A radio frequency amplifier comprises a differential amplifier having a pair of differential first and second transistors and a first and a second load resistor; an emitter grounded amplifier having a third transistor and a third load resistor; and a reference voltage generator having a constant-current source formed by a fourth transistor and a fourth load resistor. The emitter grounded amplifier receives a high frequency input signal and outputs a single signal output. One input node of the differential amplifier receives the output from the emitter grounded amplifier and the other input node receives a reference voltage from the reference voltage generator. The third and fourth transistors form a current-mirror circuit.

Abstract: A differential output is provided from a single-ended input by a switched-capacitor stage having a through-switched capacitor coupled via an amplifier to one output terminal and a diagonally-switched capacitor coupled via an amplifier to another output terminal. Each amplifier is provided with a through-switched negative feedback capacitor. A delay inherent in the switching of the diagonally-switched capacitor provides an interpolation effect in the differential output.

Abstract: Two high voltage power supplies having negative outputs with respect to common are combined to provide positive as well as negative output with respect to common. An operational preamplifier is used as an inverter. The combination includes provision for programming by means of a voltage returned to common making the system compatible with Conventional remote control systems.