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.

The present exemplary embodiments provide an audio signal muting apparatus and a digital signal conversion apparatus which remove a negative pop noise in a predetermined large range using a negative power for the transistor of the audio signal muting apparatus.

A method of controlling a signal power of a received signal received by a wireless communication device, the method including: measuring the signal power of the received signal at a plurality of time points in response to a gain control signal; calculating a variance of the signal power of the received signal at at least some time points of the plurality of time points; and controlling the signal power of the received signal based on a gain level determined according to the variance of the signal power of the received signal.

In some embodiments, a calibration circuit for an audio amplification system can include a tone generator configured to provide a tone having a frequency to an input path of an audio amplifier, such that an input signal provided to the audio amplifier includes the tone, a a first sampling circuit configured to sample an output signal at an output node of the audio amplifier, and a second sampling circuit configured to sample the input signal at an input node of the audio amplifier. The calibration circuit can further include a gain adjustment circuit configured to generate a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

An integrated circuit includes a transimpedance amplifier and an injection circuit. The injection circuit generates a first electrical test signal and injects the first electrical test signal into the transimpedance amplifier. The first electrical test signal or an output of the transimpedance amplifier generated based on the first electrical test signal is used to determine whether the integrated circuit is faulty.

A transimpedance amplifier circuit includes an amplifier circuit that converts a current signal into a voltage signal with a gain being varied based on a control signal and a gain control circuit that generates the control signal based on an amplitude of the voltage signal. The gain control circuit includes a detection circuit that generates an amplitude-detection-signal in accordance with the amplitude of the voltage signal, a setting circuit that generates an amplitude-reference-signal, a differential voltage generation circuit that generates a differential-voltage-signal obtained by offsetting a voltage difference between the amplitude-detection-signal and the amplitude-reference-signal based on an amplitude-setting-signal, an operational transconductance amplifier (OTA) that generates a differential-current-signal based on the differential-voltage-signal, and a variable capacitor circuit having a variable capacitance being varied based on the amplitude-setting-signal, and configured to be charged/discharged by the differential-current-signal and output a charging voltage. The control signal is generated based on the charging voltage.

In one embodiment, an apparatus includes: a low noise amplifier (LNA) to receive and amplify a radio frequency (RF) signal, the LNA having a first controllable gain; a mixer to downconvert the RF signal to a second frequency signal; a programmable gain amplifier (PGA) coupled to the mixer to amplify the second frequency signal, the PGA having a second controllable gain; a digitizer to digitize the second frequency signal to a digitized signal; a demodulator coupled to the digitizer to demodulate the digitized signal; an automatic gain control (AGC) circuit to control one or more of the first controllable gain and the second controllable gain; and an AGC settling circuit to cause the demodulator to begin operation in response to determining that the AGC circuit has settled.

A control device includes: a difference calculator that calculates a maximum gain difference between frequency characteristics of an audio signal and desired frequency characteristics in a predetermined frequency band; a center frequency calculator that calculates a center frequency between a first frequency at which the gain difference is 1/√2 times the maximum gain difference and which is closest to a peak frequency corresponding to the maximum gain difference among one or more frequencies lower than the peak frequency and a second frequency at which the gain difference is 1/√2 times the maximum gain difference and which is closest to the peak frequency among one or more frequencies higher than the peak frequency; a determiner that determines parameters of an equalizer based on the maximum gain difference and the center frequency; and an outputter that outputs the parameters to the equalizer.

Radio frequency (RF) front ends with integrated channel matching calibration are provided herein. In one aspect, a front end system includes: a plurality of front end amplification chains including transmit and receive chains for at least two radio frequency bands, each of the front end amplification chains configured to either transmit or receive radio frequency signals via one of a plurality of antennas, and each of the front end amplification chains includes an amplifier configured to receive a bias current and amplify the corresponding radio frequency signal based on the bias current, a control circuit configured to generate each of the bias currents, and a multiplexor configured to receive the bias currents and provide the bias currents to the corresponding amplifiers.

A system for power amplifier control includes a processor, a memory in communication with the processor, wherein the processor and the memory are configured to simultaneously provide input signal strength of each of a plurality of power amplifiers in a millimeter wave (mmW) phased array system, determine an average input signal strength of the plurality of power amplifiers based on the provided input signal strengths using an analog-to-digital converter (ADC), determine a voltage headroom for the plurality of power amplifiers based on the determined average input signal strength, estimate a power backoff value based on the voltage headroom, and determine a gain control value based on the estimated power backoff value.