Temperature compensation circuits and methods for adjusting one or more circuit parameters of a power amplifier (PA) to maintain approximately constant Gain versus time during pulsed operation sufficient to substantially offset self-heating of the PA. Some embodiments compensate for PA Gain droop due to self-heating using a Sample and Hold (S&H) circuit. The S&H circuit samples and holds an initial temperature of the PA at commencement of a pulse. Thereafter, the S&H circuit generates a continuous measurement that corresponds to the temperature of the PA during the remainder of the pulse. A Gain Control signal is generated that is a function of the difference between the initial temperature and the operating temperature of the PA as the PA self-heats for the duration of the pulse. The Gain Control signal is applied to one or more adjustable or tunable circuits within a PA to offset the Gain droop of the PA.

A radio frequency front end of a user equipment for reducing power consumption includes a receive chain having a first low noise amplifier stage, a transmit chain including a first power amplifier stage, a transmit bypass path, a receive bypass path and a time division duplex switch. The transmit bypass path is selectively coupled to a transmit signal path at a first intermediate point of the transmit chain, prior to the first power amplifier stage. The receive bypass path is selectively coupled to a receive signal path at a first intermediate point of the receive chain after the first low noise amplifier stage. The time division duplex switch is selectively coupled to an antenna, the transmit bypass path, the receive bypass path, the first power amplifier stage and the first low noise amplifier stage.

A power amplification module includes a first amplification transistor that receives a first signal outputs an amplified second signal from the collector thereof; and a bias circuit that supplies a bias current to the base of the first amplification transistor. The first bias circuit includes a first transistor that is diode connected and is supplied with a bias control current; a second transistor that is diode connected, the collector thereof being connected to the emitter of the first transistor; a third transistor, the base thereof being connected to the base of the first transistor, and the bias current being output from the emitter thereof; a fourth transistor, the collector thereof being connected to the emitter of the third transistor and the base thereof being connected to the base of the second transistor; and a first capacitor between the base and the emitter of the third transistor.

A Doherty amplifier circuit comprising: a splitter having: a splitter-input-terminal for receiving an input signal; a main-splitter-output-terminal; and a peaking-splitter-output-terminal; a main-power-amplifier having a main-power-input-terminal and a main-power-output-terminal, wherein; the main-power-input-terminal is connected to the main-splitter-output-terminal; and the main-power-output-terminal is configured to provide a main-power-amplifier-output-signal; a peaking-power-amplifier having a peaking-power-input-terminal and a peaking-power-output-terminal, wherein: the peaking-power-input-terminal is connected to the peaking-splitter-output-terminal; and the peaking-power-output-terminal is configured to provide a peaking-power-amplifier-output-signal. The splitter, the main-power-amplifier and the peaking-power-amplifier are provided by means of an integrated circuit.

In a power amplifier module for performing slope control of a transmitting signal, a gain variation due to a variation in battery voltage is suppressed while suppressing an increase in circuit size. The power amplifier module includes: a first regulator for outputting a first voltage corresponding to a control voltage for controlling a signal level; a second regulator for outputting a second voltage that rises as a battery voltage drops; a first amplifier supplied with the first voltage as a power-supply voltage to amplify an input signal and output an amplified signal; and a second amplifier for amplifying the amplified signal, wherein the second amplifier includes a first amplification unit supplied with the second voltage as the power-supply voltage to amplify the amplified signal, and a second amplification unit supplied with the battery voltage as the power-supply voltage to amplify the amplified signal.

A transmission module includes an amplifier that amplifies a plurality of transmission signals in different frequency bands, a power supply voltage regulator circuit that supplies different power supply voltages for the respective frequency bands of the transmission signals to the amplifier, and a variable matching circuit including at least one variable capacitor element and at least one fixed inductor element. The variable matching circuit satisfies different output impedance matching conditions of the amplifier for the respective frequency bands of the transmission signals by changing a capacitance value of the at least one variable capacitor element on the basis of a change in the output impedance matching conditions of the amplifier in response to a change in the power supply voltages supplied to the amplifier.

A radio frequency front end of a user equipment for reducing power consumption includes a receive chain having a first low noise amplifier stage, a transmit chain including a first power amplifier stage, a transmit bypass path, a receive bypass path and a time division duplex switch. The transmit bypass path is selectively coupled to a transmit signal path at a first intermediate point of the transmit chain, prior to the first power amplifier stage. The receive bypass path is selectively coupled to a receive signal path at a first intermediate point of the receive chain after the first low noise amplifier stage. The time division duplex switch is selectively coupled to an antenna, the transmit bypass path, the receive bypass path, the first power amplifier stage and the first low noise amplifier stage.

A power amplifier module includes a first current source that outputs a first current corresponding to a level control voltage for controlling a signal level of an amplified signal, a second current source that outputs a second current corresponding to the level control voltage, a first transistor in which an input signal and a first bias current are supplied to a base and an emitter is grounded, a second transistor in which an emitter is connected to a collector of the first transistor, the second current is supplied to a base, and a first amplified signal obtained by amplifying the input signal is output from a collector, and a third transistor in which the first current is supplied to a collector, a bias control current or voltage is supplied to a base, and the first bias current is supplied from an emitter to the base of the first transistor.

This application provides example variable gain amplifiers and example phased array transceivers. One example variable gain amplifier includes an amplification circuit, configured to amplify an input signal; a control circuit, configured to control a gain of the amplification circuit by adjusting an output current of the amplification circuit; an inductive load, where the inductive load is coupled to a signal output end of the amplification circuit; and an inductive adjustment circuit, where the inductive adjustment circuit and the inductive load are inductively coupled, and where the inductive adjustment circuit is adjustable.

A power amplification module includes a first input terminal that receives a first transmit signal in a first frequency band, a second input terminal that receives a second transmit signal in a second frequency band having a narrower transmit/receive frequency interval than the first frequency band, a first amplification circuit that receives and amplifies the first transmit signal to produce a first amplified signal and outputs the first amplified signal, a second amplification circuit that receives and amplifies the second transmit signal to produce a second amplified signal and outputs the second amplified signal, a third amplification circuit that receives and amplifies the first or second amplified signal to produce an output signal and outputs the output signal, and an attenuation circuit located between the second input terminal and the second amplification circuit and configured to attenuate a receive frequency band component of the second frequency band.