In a gain control device, a gain control voltage adjust circuit includes a time-constant circuit and outputs an adjusted gain control voltage depending on an adjustment signal and a control voltage generated by a differential amplifier upon input of the adjustment signal. An adjustment signal generation circuit outputs the adjustment signal during an adjustment signal output period. This period is a specified period before a first burst signal is output from a signal output unit and where a burst signal is not output from the signal output unit. The adjustment signal is to make the adjusted gain control voltage closer to a target voltage. The target voltage is a gain control voltage output from the gain control voltage adjust circuit and corresponding to a steady part of a second burst signal. The second burst signal is a burst signal output before the first burst signal.

An improved method of providing high burst power to audio amplifiers from limited power sources, using parallel power paths to increase system efficiency without need for a power path controller, thus utilizing a simplified circuit operation and maximizing average power available for both the amplifier and supporting circuitry.

An amplifier includes a first circuitry, a second circuitry, and a plurality of amplifier circuitries. The first circuitry controls an enable signal. The second circuitry controls a bias signal. Circuitries which output signals are decided from among the plurality of circuitries based on the enable signal, and each of the circuitries which output the signals amplifies an input signal with a gain corresponding to the bias signal.

The present invention is directed to systems and methods for reducing noise levels by harmonization in a DCC-DAS using smart weighted aggregation of noise and signal resources to achieve an optimal signal to noise ratio in varying traffic and interference conditions.

Various embodiments are directed to apparatuses and methods to generate a first signal representing modulation data and a second signal representing an amplitude of the modulation data, the first signal and the second signal to depend on an output signal and vary a power supply voltage to a gain stage in proportion to the amplitude of the modulation data.

Apparatus and methods for vector modulator phase shifters are provided. In certain embodiments, a phase shifter includes a quadrature filter that filters a differential input signal to generate a differential in-phase (I) voltage and a differential quadrature-phase (Q) voltage, an in-phase variable gain amplifier (I-VGA) that amplifies the differential I voltage to generate a differential I current, a quadrature-phase variable gain amplifier (Q-VGA) that amplifies the differential Q voltage to generate a differential Q current, and a current mode combiner that combines the differential I voltage and the differential Q voltage to generate a differential output signal. A phase difference between the differential output signal and the differential input signal is controlled by gain settings of the I-VGA and the Q-VGA.

A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

An output power control device includes: an attenuator to attenuate power of a high-frequency signal output from an oscillator; a high-frequency power amplifier to amplify the power of the high-frequency signal output from the attenuator; a monitor circuit to monitor the power of the high-frequency signal output from the high-frequency power amplifier; and a controller to control an attenuation amount of the attenuator based on the monitor signal output from the monitor circuit or based on attenuation amount setting data from a data unit. The oscillator generates the high-frequency signal in synchronization with a trigger signal. The controller starts control of the attenuation amount of the attenuator based on the attenuation amount setting data, in synchronization with the trigger signal, and, after receiving the monitor signal, the controller controls the attenuation amount of the attenuator based on the monitor signal.

The disclosed technology relates generally to semiconductor devices, and more particularly to power semiconductor devices in which effects of charge trapping are compensated. A radio frequency (RF) power transmitter system comprises a RF power semiconductor device that outputs a time-varying gain characteristic from a RF signal input waveform originating from a digital input, wherein the time-varying gain characteristic includes a gain error associated with charge-trapping events having a memory effect on the RF power semiconductor device lasting longer than 1 microsecond. The RF power transmitter system further comprises circuitry configured to apply an analog gate bias waveform to the RF power semiconductor device based on the time-varying gain characteristic to reduce the gain error.

An improved method of providing high burst power to audio amplifiers from limited power sources, using parallel power paths to increase system efficiency without need for a power path controller, thus utilizing a simplified circuit operation and maximizing average power available for both the amplifier and supporting circuitry.