Abstract: In one aspect, a time division interleaving band-pass filter can be used in voice activity detection, which operates at different central frequencies in respective intervals of a predetermined period of time. The band-pass filter circuitry includes multiple band-pass filtering channels sharing a common transistor circuit, bias circuit and current mirror circuit. The multiple band-pass filtering channels operate in a time division interleaving manner, which enables the sharing of the common set of band-pass filter circuitry components. Thus, the present invention allows a reduced chip area as the area does not increase proportionally with the number of filtering channels. The invention also mitigates the influence of transistor fabrication variations on the filter's central frequencies.

Abstract: A microphone includes a MEMS device having an output node for generating an analog voltage in response to an input sound wave or vibration; a source follower having a control node coupled to the output node of the MEMS device, a current path coupled between a first controlled node and a second controlled node, and a bulk node, wherein the first controlled node is configured for providing a microphone output voltage, and wherein the second controlled node is coupled to a reference voltage; a current source coupled to the first controlled node; and a voltage differential between the first controlled node and the bulk node, wherein a nonzero value of the voltage differential is configured such that a first 1% total harmonic distortion (THD) cross-point of the microphone output voltage is greater than a second 1% THD cross-point of the microphone output voltage using a zero value voltage differential.

Abstract: Reducing a sensitivity of an electromechanical sensor is presented herein. The electromechanical sensor comprises a sensitivity with respect to a variation of a mechanical-to-electrical gain of a sense element of the electromechanical sensor; and a voltage-to-voltage converter component that minimizes the sensitivity by coupling, via a defined feedback capacitance, a positive feedback voltage to a sense electrode of the sense element—the sense element electrically coupled to an input of the voltage-to-voltage converter component. In one example, the voltage-to-voltage converter component minimizes the sensitivity by maintaining, via the defined feedback capacitance, a constant charge at the sense electrode. In another example, the electromechanical sensor comprises a capacitive sense element comprising a first node comprising the sense electrode. Further, a bias voltage component can apply a bias voltage to a second node of the electromechanical sensor.

Abstract: A circuit includes an operational amplifier, a plurality of input capacitors, a plurality of output capacitors, a plurality of sampling switches, a plurality of holding switches, a plurality of combined switches. The input capacitors include a first input capacitor and a second input capacitor. The output capacitors include a first output capacitor and a second output capacitor. The sampling switches include a first sampling switch, a second sampling switch, a third sampling switch and a fourth sampling switch. The holding switches include a first holding switch and a second holding switch. The combined switches include a first combined switch and a second combined switch.

Abstract: An amplifying circuit including a first gain circuit, a second gain circuit, a Miller capacitor, a positive feedback circuit and a feedforward gain circuit. The second gain circuit is configured to receive a first gain signal from the first gain circuit and generate a second gain signal. The Miller capacitor, the positive feedback circuit and the feedforward gain circuit are electrically coupled between an input terminal and an output terminal of the second gain circuit. The positive feedback circuit is configured to feedback the signal of the output terminal of the second gain circuit to the input terminal of the second gain circuit. The feedforward gain circuit is configured to amplify the first gain signal to output a third gain signal to the output terminal of the second gain circuit.

Abstract: Various embodiments of the present technology may provide methods and apparatus for a track-and-hold amplifier configured to sample and amplify an analog signal. Methods and apparatus for a track-and-hold amplifier according to various aspects of the present invention may provide an isolation circuit configured to isolate transient current in a track-and-hold capacitor during a track phase. According to various embodiments, selective activation of the isolation circuit provides a settling time that is independent of the gain of the amplifier.

Abstract: A communication apparatus includes a generation unit that generates the first I signal and the first Q signal as signals that allow a carrier wave to undergo frequency shift keying with predetermined modulated data and inputs the first I signal and the first Q signal to a quadrature modulation unit. A first demodulation unit and the first decoding unit demodulate and decode first data that undergoes amplitude shift keying and is transmitted from the wireless tag. A second demodulation unit and the second decoding unit demodulate and decode second data that undergoes frequency shift keying from a wireless signal output from the wireless tag. A comparison unit compares the second data and the modulated data to each other. The processor executes, when matching between the second data and the modulated data is confirmed by the comparison unit, data processing on the first data.

Abstract: Disclosed herein is a voltage gain amplifier for use in an automotive radar receiver chain. The voltage gain amplifier utilizes pole-zero cancelation to yield a desired transfer function without gain peaking at a bandwidth in which attenuation is desired, and utilizes a low pass filter effectively formed by a feedback loop including a high pass filter and a differential amplifier to ensure the desired level of attenuation at the desired bandwidth. In some instances, a chopper may be utilized in the feedback loop prior to the high pass filter, and after the differential amplifier, so as to reduce the bandwidth of the differential amplifier in the feedback loop.

Abstract: Certain aspects of the present disclosure are generally directed to circuitry and techniques for current sensing. For example, certain aspects provide a circuit for signal amplification including a first amplifier, a second amplifier, and a third amplifier. The circuit also includes a first capacitive element coupled between a first output of the first amplifier and a first input of the third amplifier, a second capacitive element coupled between a second output of the first amplifier and a second input of the third amplifier, a third capacitive element coupled between a first output of the second amplifier and the first input of the third amplifier, and a fourth capacitive element coupled between a second output of the second amplifier and the second input of the third amplifier.

Abstract: A frequency modulation demodulation device and a control method thereof are provided. The frequency modulation demodulation device includes an input terminal, a phase converter, a phase-locked loop circuit, and a frequency offset/shift detector. The phase converter receives an input signal to obtain a phase signal. The phase-locked loop circuit generates a phase adjustment signal according to the phase signal and adjusts the phase signal according to the phase adjustment signal to perform demodulation of the input signal. The phase-locked loop circuit performs signal alignment and signal compensation on the phase signal to generate a filtered phase signal. The phase adjustment signal provides a feedback of and adjusts the phase signal. The frequency offset/shift detector generates a frequency offset/shift determining signal according to the phase adjustment signal. The frequency offset/shift determining signal is related to a phase frequency offset/shift of the input signal.

Abstract: The disclosure provides an improved transimpedance amplifier (TIA) that can operate at a higher bandwidth and lower noise compared to conventional TIAs. The TIA employs a data path with both feedback impedance and feedback capacitance for improved performance. The feedback impedance includes at least two resistors in series and at least one shunt capacitor, coupled between the at least two resistors, that helps to extend the circuit bandwidth and improve SNR at the same time. The capacitance value of the shunt capacitor can be selected based on both the bandwidth and noise. In one example, the TIA includes: (1) a biasing path, and (2) a data path, coupled to the biasing path, including multiple inverter stages and at least one feedback capacitance coupled across an even number of the multiple inverter stages. An optical receiver and a circuit having the TIA are also disclosed.

Abstract: A method of designing a microwave filter using a computerized filter optimizer, comprises generating a filter circuit design in process (DIP) comprising a plurality of circuit elements having a plurality of resonant elements and one or more non-resonant elements, optimizing the DIP by inputting the DIP into the computerized filter optimizer, determining that one of the plurality of circuit elements in the DIP is insignificant, removing the one insignificant circuit element from the DIP, deriving a final filter circuit design from the DIP, and manufacturing the microwave filter based on the final filter circuit design.

Abstract: A power amplifier includes a first amplifier configured to output a signal based on a difference between an input signal and a feedback signal; a second amplifier that amplifies the power of the signal output from the first amplifier and outputs the amplified signal; a first feedback circuit that feeds the signal output from the second amplifier back to the first amplifier; a third amplifier that amplifies the power of the signal output from the second amplifier and outputs the amplified signal; and a second feedback circuit that feeds the signal output from the third amplifier back to the first amplifier, in which the feedback signal is a signal obtained by combining an output signal of the first feedback circuit with an output signal of the second feedback circuit.

Abstract: A loudspeaker apparatus includes a first loudspeaker unit and a second loudspeaker unit that reproduce sound at least at a high frequency. The first loudspeaker unit and the second loudspeaker unit are placed on a plane having an axis extending in a horizontal direction and an axis extending in a vertical direction. The first loudspeaker unit is placed so as to be directed horizontally forward. The second loudspeaker unit is placed so as to be directed vertically upward to make an approximately 90° angle with the first loudspeaker unit.

Abstract: A reference buffer circuit comprises a dual-difference amplifier circuit including a first differential input, a second differential input, and a differential output that provides a differential reference signal; a first reference voltage coupled to a first input of the first differential input and a second reference voltage coupled to a first input of the second differential input; and wherein outputs of the differential output are connected by a feedback circuit path to second inputs of the first and second differential inputs.

Abstract: Systems, devices, and methods for determining and establishing frequency-dependent gain compensation in wide bandwidth communication systems are disclosed. Variable frequency-dependent gain compensation circuits, or variable equalizers, have settings that configure them to establish discrete frequency-dependent gain compensation. The frequency-dependent gain compensation can include various types and levels of gain slope and/or ripple. The settings of the variable equalizers can be set by control signals established a control circuit in response to signals from an external computer. The variable equalizers are coupled to other circuits or devices and the frequency-dependent gain of the combined circuit are measured. The settings of the variable equalizer are then changed to establish an optimal frequency-dependent gain profile or frequency-dependent gain that is closest to a predetermined frequency-dependent target gain profile. The settings can then be saved in a memory or register.

Abstract: A low noise amplifier has integral noise cancellation to provide a low noise figure and operation over a frequency range of 0.5 GHz-50 GHz. An amplifier amplifies an input signal as well as noise present with the amplified signal and amplified noise being out of phase and in phase, respectively, with the corresponding inputs. A feedback circuit that is non-linear with frequency enables a constant amplification. A summation circuit combines amplified signals with the noise being cancelled since two combined noise signals being summed are 180 degrees out of phase to each other. An optional secondary amplification stage provides additional amplification. Preferably, the amplifier, auxiliary amplifier and the summation device utilize CMOS transistors disposed on an SOI substrate with impedance stabilization over the frequency range.

Abstract: A nested ammeter for measuring the electrical current flowing through a device under test (DUT) can include an input configured to receive an input signal having a frequency within a frequency band and representing the electrical current flowing through the DUT. The nested ammeter can also include an output configured to generate an output voltage representing the electrical current flowing through the DUT. An active shunt can be used as the resistive feedback of the ammeter. A nested active shunt can be used as the resistive feedback element of the active shunt.

Abstract: A power amplifier system can include a power amplifier that provides amplification to a radio frequency signal associated with a first frequency band and outputs an amplified radio frequency signal. An acoustic wave bandpass filter such as a surface acoustic wave or bulk acoustic wave bandpass filter is arranged in a feedback configuration with respect to the power amplifier. The filter can pass through a portion of the amplified radio frequency signal corresponding to a second frequency to provide negative feedback to the power amplifier, resulting in a reduction in an amount of gain from the power amplifier within the second frequency band.

Abstract: A power amplifier system can be configured to provide amplification to a radio frequency signal associated with a first frequency band and to output an amplified radio frequency signal. The system can include a bandpass filter arranged in a feedback loop with respect to the power amplifier and configured to pass through a portion of the amplified radio frequency signal corresponding to a second frequency band. A first shifter can be positioned in the feedback loop, and an output of the feedback loop can provide negative feedback to an input of the power amplifier.

Abstract: A reference voltage generator may include: a differential amplification circuit including a positive input terminal coupled to a supply voltage to receive a voltage from the supply voltage and a negative input terminal coupled to an output terminal of the differential amplification circuit, the differential amplification circuit structured to perform a reset operation based on the received voltage from the supply voltage during a reset period and amplify a difference between a first initial voltage applied to the positive input terminal and a second initial voltage applied to the negative input terminal during a reference voltage generation period; and first and second voltage storage circuits coupled to the positive input terminal and the negative input terminal, respectively, and structured to store the first initial voltage and the second initial voltage, respectively.

Abstract: A loudspeaker system including a pair of elongated arrays of electrodynamic drivers, each array being composed of a plurality of drivers of the same type and size. The drivers are driven by electrical signals from an audio signal converter that receives an electrical audio signal representative of sound waves to be reproduced by the loudspeaker system and converts the electrical audio signal to a modified electrical audio signal by applying an inverse of the composite electromechanical bandpass transfer function and an inverse of the composite acoustical impedance high-pass transfer function to the electrical audio signal. The drivers may be circular drivers with a nominal size (diameter) of two to four inches.

Abstract: A MEMS apparatus with dynamic displacement control includes a MEMS parallel plate capacitor integrated with one or more memristors in a series configuration wherein a displacement is observable as a function of memristance, such that an upper electrode position is capable of being interpreted in a form of a resistance rather than a capacitance. The current is limited by said MEMS parallel plate capacitor restricting a change in the resistance of the memristor(s). The memristor(s) can be employed in some embodiments a sensor element to improve a MEMS operation range.

Abstract: Systems, devices, and methods for determining and establishing frequency-dependent gain compensation in wide bandwidth communication systems are disclosed. Variable frequency-dependent gain compensation circuits, or variable equalizers, have settings that configure them to establish discrete frequency-dependent gain compensation. The frequency-dependent gain compensation can include various types and levels of gain slope and/or ripple. The settings of the variable equalizers can be set by control signals established a control circuit in response to signals from an external computer. The variable equalizers are coupled to other circuits or devices and the frequency-dependent gain of the combined circuit are measured. The settings of the variable equalizer are then changed to establish an optimal frequency-dependent gain profile or frequency-dependent gain that is closest to a predetermined frequency-dependent target gain profile. The settings can then be saved in a memory or register.

Abstract: An error-feedback transmitter includes an input that receives an input signal, and an output that produces an output signal. It also includes an amplifier, located on a main path that carries a main signal between the input and the output. The transmitter includes a feedback path that carries a feedback signal from the output to the input, and a feedback-signal combiner, located on the main path between the input and the amplifier. The feedback-signal combiner negatively combines the feedback signal with the input signal to improve linearity in the output signal. The transmitter includes a feedforward path that carries a feedforward signal from the input toward the output, and a feedforward-signal combiner, located on the feedback path between the output and the feedback-signal combiner. The feedforward-signal combiner negatively combines the feedforward signal with the feedback signal to suppress components of the main signal in the feedback signal.

Abstract: An image sensor comprises an array of pixels comprising: a pinned photodiode; a first sense node A; a second sense node B; a transfer gate TX connected between the pinned photodiode and the first sense node A; a first reset transistor M3 connected between a voltage reference line Vrst and the second sense node B; a second reset transistor M4 connected between the first sense node A and the second sense node B; and a buffer amplifier M1 having an input connected to the first sense node A. The control logic is arranged to operate the pixels in a low conversion gain mode and in a high conversion gain mode. In each of the conversion gain modes the control logic is arranged to operate one of a first reset control line RS1 and a second reset control line RS2 to continuously switch on one of the first reset transistor M3 and the second reset transistor M4 during a readout period of an operational cycle of the pixels.

Abstract: A semiconductor device includes an amplifier, a pass transistor, a compensation circuit, and a bias voltage generator. The amplifier has an output terminal. The pass transistor has a gate and an output terminal. The gate is coupled to the output terminal of the amplifier, and the output terminal of the pass transistor is coupled to a load. The compensation circuit is coupled between the output terminal of the amplifier and the output terminal of the pass transistor. The compensation circuit has a variable impedance. The bias voltage generator is coupled between the output terminal of the pass transistor and the compensation circuit.

Abstract: An envelope signal time delay adjustment apparatus includes a negative group delay unit for converting an envelope signal input from a signal generator into an envelope signal having a group delay of a negative value whose frequency increases from a predetermined frequency band; an envelope-tracking modulator for power-amplifying and outputting the envelope signal output from the negative group delay unit; and a frequency limiting unit for limiting a bandwidth of the envelope-tracking modulator to be lower than an original bandwidth of the envelope-tracking modulator.

Abstract: Devices for improving the quality of sound output by a speaker. For example, the device may act to remove ultrasonic frequencies from an audio signal prior to the audio signal being output by a speaker. In other examples, the device may act to impede the progress of harmonic distortion, intermodulation distortion, and environmental noise feeding back into the source device.

Abstract: An apparatus includes a multi-stage amplifier. The multi-stage amplifier includes first, second, and third amplifier circuits coupled in a cascade configuration. The multi-stage amplifier further includes first, second, and third compensation networks. The first compensation network is coupled between the output of the third amplifier circuit and the input of the second amplifier circuit. The second compensation network is coupled between the output of the third amplifier circuit and the input of the third amplifier circuit. The third compensation network is coupled between the output of the second amplifier circuit and the input of the second amplifier circuit.

Abstract: The present disclosure includes systems and techniques relating to time-varying notch filter. In one implementation, an apparatus includes a time-variant notch filter and a controller. The time-variant notch filter includes a notch depth and a notch bandwidth centered on a notch frequency. At least one of the notch depth or the notch bandwidth is based on a coefficient of the notch filter. The controller is configured to estimate a power of a packet being received and compare the estimated power of the packet to a predetermined threshold. The controller is also configured to set, conditioned on determining that the estimated power of the packet is greater than the predetermined threshold, a value of the coefficient to a first value such that the packet bypasses the time-variant notch filter.

Abstract: A linear regulator includes a drive circuit having an input and an output, with the output configured to drive a control terminal of a power transistor for the delivery of a load current. An error amplifier functions to amplify a difference between a reference signal and a feedback signal to generate an error signal at the input of the drive circuit. A compensation circuit includes a series circuit formed by a compensation capacitor and a variable resistance circuit, where the series circuit is coupled to the input of the drive circuit. A current sensing circuit operates to sense the load current. The resistance of the variable resistance circuit is varied in response to the sensed load current.

Abstract: A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.

Abstract: Systems, devices, and methods for determining and establishing frequency-dependent gain compensation in wide bandwidth communication systems are disclosed. Variable frequency-dependent gain compensation circuits, or variable equalizers, have settings that configure them to establish discrete frequency-dependent gain compensation. The frequency-dependent gain compensation can include various types and levels of gain slope and/or ripple. The settings of the variable equalizers can be set by control signals established a control circuit in response to signals from an external computer. The variable equalizers are coupled to other circuits or devices and the frequency-dependent gain of the combined circuit are measured. The settings of the variable equalizer are then changed to establish an optimal frequency-dependent gain profile or frequency-dependent gain that is closest to a predetermined frequency-dependent target gain profile. The settings can then be saved in a memory or register.

Abstract: The present invention provides a power gain-boosting technique for an amplifier in order to compensate for the decrease of Gmag in a transistor at high frequencies. A power gain-boosting technique of the present invention comprises the steps of: finding the Maximum Unilateral Gain or Mason's Invariant U of a transistor; designing a linear, lossless, reciprocal network embedding the transistor so that the final equivalent S-, Y-, or Z-parameters satisfy the condition: S ? 21 S 12 = Y 2 ? ? 1 Y 1 ? ? 2 = Z 2 ? ? 1 Z 1 ? ? 2 = - [ ( 2 ? U - 1 ) + 2 ? U ? ( U - 1 ) ] ; embedding the transistor into the linear, lossless, reciprocal network; and constructing simultaneous conjugate matching.

Abstract: The present invention discloses a gain-boosted N-path SC bandpass filter (GB-BPF) with a number of sought features. It is based on a transconductance amplifier (Gm) with an N-path SC branch as its feedback network, offering 1) double RF filtering at the input and output of the Gm in one step; 2) customized passband gain and bandwidth with input-impedance match, and 3) reduced physical capacitance thanks to the loop gain offered by Gm. All have been examined using a RLC model of the SC branch before applying the linear periodically time-variant (LPTV) analysis to derive the R, L and C expressions and analytically study the harmonic selectivity, harmonic folding and noise. The latter reveals that: 1) the noise due to the switches is notched at the output, allowing smaller switches to save the LO power; and 2) the noises due to the source resistance and Gm are narrowband at the output, reducing the folded noise during harmonic mixing.

Abstract: A communication device is provided. The communication device includes an antenna unit, a sensing unit and a radio frequency unit. The antenna unit is configured to transmit a radio frequency signal. The sensing unit is coupled to a ground terminal through a first capacitor. The sensing unit is configured to sense a capacitance value through the antenna unit. The radio frequency unit is configured to generate the radio frequency signal and to regulate the energy of the radio frequency signal according to the capacitance value.

Abstract: An amplifier circuit amplifies a signal for wireless transmission. A feedback circuit, including a capacitor, is coupled to the amplifier circuit. Components of the feedback circuit are selected based on a feedback factor such that an input impedance to the amplifier circuit has a same impedance characteristic as a feedback circuit impedance of the feedback circuit.

Abstract: An amplifier circuit including an amplifier, a first feedback path, and a second feedback path. The amplifier is configured to amplify an input signal in accordance with a gain. The first feedback path includes a first capacitance, and responsive to the input signal being within in a first frequency range, the first feedback path configured to provide feedback from the output of the amplifier to an inverting input of the amplifier. The second feedback path includes a first resistance connected in series with a second capacitance, and responsive to the input signal being within in a second frequency range, the second feedback path is configured to provide feedback from the output of the amplifier to the inverting input of the amplifier. The second frequency range is less than the first frequency range, and the gain of the amplifier levels off according to a value of the second capacitance.

Abstract: The present disclosure relates to a front-end system for a radio device, the front-end system comprising a low-noise amplifier (LNA), arranged for receiving a radio frequency input signal (RFIN) and arranged for outputting an amplified radio frequency signal (RFOUT), wherein the low-noise amplifier comprises a first differential amplifier, and a mixer (MIX), arranged for down-converting the amplified radio signal (RFOUT) provided by the low-noise amplifier (LNA) to a baseband signal (BB), by multiplying the amplified radio signal (RFOUT) with a local oscillator (LO) frequency tone, said low-noise amplifier (LNA) and said mixer (MIX) being inductively coupled.

Abstract: The present invention provides a sensor system and a corresponding sensing method employing the sensor system. The sensor system comprises a sensor (12) having an input (20) and an output (22), a feedback path (16) from the output to the input, and a filter (14; 92) in the feedback path. The filter comprises a narrow band filter, which is tuned or tunable to a respective one of signals that are wanted signals and signals that represent interference signals. The sensor and the filter are arranged so as to alter the relative amplitudes of the wanted signals and the interference signals in order to increase the relative amplitude of the wanted signals and reduce the relative amplitude of the interference signals.

Abstract: A self-oscillating driver circuit includes a driver stage, a feedforward path which is coupled to an input of the driver stage, and a feedback path which couples an output of the driver stage to an input of the feedforward path. The feedforward path includes a feedforward filter which is designed as an active filter. In order to prevent an oscillatory state of the driver circuit at an unwanted frequency, it is proposed that an internal state variable of the feedforward filter be monitored and that the feedforward filter be reset if the value of the monitored internal state variable is outside a predefined range.

Abstract: An amplifier circuit comprises a measurement path with an amplifier (1) for providing an output voltage (Vout) depending on a measuring current (Ipd) with a first and a second amplifier input (11, 12), and an amplifier output (13). A return path of the amplifier circuit comprises a first filter (2), an auxiliary amplifier (3) and a second filter (4). In this case, the first filter (2) is designed to filter a DC voltage from the output voltage (Vout) and is connected to the amplifier output (13). The auxiliary amplifier (3) serves to convert an input voltage (Vfil) into an output current (Ifil) and has a first and a second auxiliary amplifier input (31, 32) and an auxiliary amplifier output (33). In this case, the first auxiliary amplifier input (31) is connected to the first filter (2). The second filter (4) is designed to filter noise from the output current (Ifil) and couples the auxiliary amplifier output (33) to the first amplifier input (11).

Abstract: An apparatus comprising a first line driver, a second line driver, a charge pump, and a control logic circuit coupled to the first line driver and the second line driver and configured to disable the charge pump when both a first control signal associated with the first line driver and a second control signal associated with the second line driver indicate a charge pump disable state. A network component comprising at least one processor configured to implement a method comprising receiving a first control signal and a second control signal, disabling a charge pump when both the first control signal and the second control signal indicate a charge pump disable state, and operating the charge pump to boost a voltage when the first control signal, the second control signal, or both indicate a charge pump active state.

Abstract: A multiband low noise amplifier (LNA) with parallel resonant feedback includes an amplifier element configured to receive a radio frequency (RF) signal at an RF input and provide an amplified version of the RF signal at an RF output, a resistive feedback circuit coupled between the RF input and the RF output, and a plurality of series-coupled resonant circuits coupled in series with the resistive feedback circuit between the RF input and the RF output of the amplifier element, wherein each of the resonant circuits is configured to operate as an effective short circuit at a frequency other than a resonant frequency and configured to operate as an effective open circuit at the resonant frequency to decouple the resistive feedback from the amplifier element at each resonant frequency.

Abstract: A radio frequency system includes a power amplifier that outputs a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network. A sensor monitors the radio frequency signal and generates first sensor signals based on the radio frequency signal. A distortion module determines a first distortion value according to at least one of (i) a sinusoidal function of the first sensor signals and (ii) a cross-correlation function of the first sensor signals. A first correction circuit (i) generates a first impedance tuning value based on the first distortion value and a first predetermined value, and (ii) provides feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to one of the power amplifier and the matching network.

Abstract: In accordance with an embodiment, a method includes determining an amplitude of an input signal provided by a capacitive signal source, compressing the input signal in an analog domain to form a compressed analog signal based on the determined amplitude, converting the compressed analog signal to a compressed digital signal, and decompressing the digital signal in a digital domain to form a decompressed digital signal. In an embodiment, compressing the analog signal includes adjusting a first gain of an amplifier coupled to the capacitive signal source, and decompressing the digital signal comprises adjusting a second gain of a digital processing block.

Abstract: According to an embodiment, a system for amplifying a signal provided by a capacitive signal source includes a first stage and a second stage. The first stage has a voltage follower device including an input terminal configured to be coupled to a first terminal of the capacitive signal source, and a first capacitor having a first end coupled to an output terminal of the voltage follower device, and a second end configured to be coupled to a second terminal of the capacitive signal source. The second stage includes a differential amplifier capacitively coupled to the output terminal of the voltage follower device.

Abstract: An analog pre-distortion linearizer having predetermined gain and phase characteristics as a function of input RF signal power is disclosed. The linearizer comprises a core circuit comprising an input terminal configured to receive an input RF signal; an output terminal configured to provide a processed version of that signal; a transistor having a gate, a drain, and a source; and a feedback circuit, presenting an impedance at the frequency of the RF signal, connected to the transistor. The gate is connected to the input terminal and the drain is connected to the output terminal. First and second dc bias voltages applied to the gate and drain respectively cause the transistor to operate at a quiescent bias point in a saturated region of the transistor I-V plane. The quiescent bias point and the impedance are selected such that the linearizer has the predetermined gain and phase characteristics.

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and/or binding events associated with chemical processes relating to DNA synthesis.