A signal processing method and system includes a baseband signal baseband signal processing module configured to perform slow envelope processing on a first signal, to obtain an envelope value E(n) of the first signal on which the slow envelope processing has been performed, obtain a phase value (n) based on E(n), where (n) and E(n) are in a linear relationship, and separate the first signal into a second signal and a third signal based on (n), where a phase difference between the second signal and the third signal is 2 (n), an amplifier configured to amplify the second signal and the third signal, and a synthesizer is configured to combine the amplified second signal and third signal to obtain a fourth signal.

A power amplifier module including an input configured to receive an input radio frequency signal, the input radio-frequency signal including a series of data symbols, an output configured to provide an output radio-frequency signal, a power amplifier having a signal input to receive the input radio-frequency signal and a power supply input to receive a supply voltage, the power amplifier configured to amplify the input radio-frequency signal to provide the output radio-frequency signal, and a controller to receive an indication of a peak output power level of an upcoming data symbol in the series of data symbols, to adjust at least the supply voltage provided to the power amplifier based on the peak output power level of the upcoming data symbol, and to configure the power amplifier module to maintain a substantially constant gain over the series of data symbols.

The present disclosure provides a radio frequency (RF) front-end of a low power consumption and fully automatic adjustable broadband receiver, including a low-noise amplification module, amplifying an broadband single-ended RF signal, and converting it into differential current signal; a local oscillator, generating a local oscillator signal; an quadrature mixer, quadraturely mixing the differential current signal and the local oscillator signal to generate intermediate frequency differential current signals; a transimpedance amplifier, converting the intermediate frequency differential current signal into an intermediate frequency differential voltage signal; an IIP2 calibration module, reducing the IIP2 effect of the RF front end; a received signal strength indicator module, sending the first amplification factor control signal and the differential mismatch control signal to the low noise amplification module, and sending the second amplification factor control signal to the transimpedance amplifier, thereby making the intermediate frequency differential voltage signals meet the requirements of the amplitude and mismatch.

A method and transmitter for a Doherty power amplifier are provided. According to one aspect, a radio transmitter includes, for each carrier frequency, a filter, a main path and a peak path. The filter suppresses signals outside the selected frequency band to produce a filter output. The main path is configured to make a first adjustment of a magnitude and phase of the filter output to produce a main path signal. The peak path is configured to make a second adjustment of the magnitude and phase of the filter output to produce a peak path signal, a difference between the first adjustment and the second adjustment being dependent on the carrier frequency. Main path signals for each carrier frequency produce a composite main path signal. Peak path signals for each carrier frequency produce a composite peak path signal.

Apparatus and methods for an inverted Doherty amplifier operating at gigahertz frequencies are described. RF fractional bandwidth and signal bandwidth may be increased over a conventional Doherty amplifier configuration when impedance-matching components and an impedance inverter in an output network of the inverted Doherty amplifier are designed based on characteristics of the main and peaking amplifier and asymmetry factor of the amplifier.

A high frequency amplifier circuit includes an input terminal and an output terminal, transmission power amplifiers (11L, 11H) that amplify a high frequency signal in first and second frequency bands, each of which is a part of a communication band, at equal to or higher than a prescribed amplification factor, respectively, switches (21, 31) that exclusively switch connection between the input terminal, the transmission power amplifier (11L), and the output terminal, and connection between the input terminal, the transmission power amplifier (11H), and the output terminal, and a transmission filter that is connected between the output terminal and the switch (31) and has a communication band as a pass band, the first frequency band including a frequency band other than the second frequency band, the second frequency band including a frequency band other than the first frequency band.

CRLH lines including left-handed shunt inductors and left-handed series capacitors are provided on gate side transmission lines of a plurality of FETs.

A balancing circuit which may compensate for bandwidth attenuation introduced by interference between signals includes an amplifying circuit, a rising edge detection circuit and/or a falling edge detection circuit. By means of detecting the rising/falling edge of an original signal, the resulting pulse signal contains the phase information of a single 0 bit and a single 1 bit in the original signal, thus the phase of a rising edge or the phase of a falling edge of the original signal may be compensated respectively, so as to compensate for the high-frequency attenuation caused by interference between signals.

According to one embodiment, a compact broadband radio frequency (RF) receiver circuit includes a low noise amplifier which includes a first amplifier stage, a second amplifier stage, an inter-stage network including a higher order filter network, where the inter-stage network is coupled between the first amplifier stage and the second amplifier stage, and a double resonance transformer network coupled to an output of the second amplifier stage. The RF receiver circuit includes a low pass filter and a mixer circuit coupled between the low noise amplifier and the low pass filter.

A transimpedance amplifier includes a T-coil in its feedback loop to expand its bandwidth. The transimpedance amplifier includes an amplifier that converts and amplifies an input current signal to an intermediary voltage signal. One terminal of the T-coil is coupled to a resistor in the feedback loop which is coupled to the input of the amplifier. Another terminal of the T-coil is coupled to the output of an amplifier. The bridge point of the T-coil is coupled to the output terminal of the transimpedance amplifier which outputs an output voltage. The T-coil includes two inductors that are mutually coupled such that a current is induced to compensate for the leakage current caused by the parasitic capacitance of the transimpedance amplifier.