Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit standby current during operation in the standby mode while allowing a quick recovery to normal operating conditions of the amplifier. Biasing an input transistor of the stacked transistors can be obtained by using a replica stack circuit.

Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit standby current during operation in the standby mode while allowing a quick recovery to normal operating conditions of the amplifier. Biasing an input transistor of the stacked transistors can be obtained by using a replica stack circuit.

Circuits comprising: a plurality of LNTA branches, each comprising: a cascode common-source (CCS) LNTA, a plurality of passive mixers (PMs), and a plurality of baseband two-stage Miller compensated TIAs (BB2S-TIAs); a plurality of mixer-first branches, each comprising: a plurality of RF switches, a plurality of baseband folded-cascode TIAs (BBFC-TIAs), and a plurality of Cherry-Hooper amplifiers, wherein an input to each of the BBFC-TIAs is provided by an output of at least one of the RF switches, and an input to each of the amplifiers is provided by an output of a corresponding one of the BBFC-TIAs; a first plurality of clock modulators that provide first non-overlapping modulated clocks that are provided to an input of the PMs; and a second plurality of clock modulators that provide a plurality of tri-level modulated mixer clocks that control the switching of the RF switches.

Circuits comprising: a plurality of LNTA branches, each comprising: a cascode common-source (CCS) LNTA, a plurality of passive mixers (PMs), and a plurality of baseband two-stage Miller compensated TIAs (BB2S-TIAs); a plurality of mixer-first branches, each comprising: a plurality of RF switches, a plurality of baseband folded-cascode TIAs (BBFC-TIAs), and a plurality of Cherry-Hooper amplifiers, wherein an input to each of the BBFC-TIAs is provided by an output of at least one of the RF switches, and an input to each of the amplifiers is provided by an output of a corresponding one of the BBFC-TIAs; a first plurality of clock modulators that provide first non-overlapping modulated clocks that are provided to an input of the PMs; and a second plurality of clock modulators that provide a plurality of tri-level modulated mixer clocks that control the switching of the RF switches.

An amplifier, including: an amplifying element, having a voltage input across a first terminal and a third terminal and a voltage controlled current path between a second terminal and the third terminal; and a trifilar transformer having a primary winding, a secondary winding and a tertiary winding; wherein the primary winding is connected to the third terminal, the secondary winding is connected to the first terminal and the tertiary winding is connected to the second terminal; wherein the primary winding and the secondary winding are mutually coupled in inverting relationship; wherein the primary winding and the tertiary winding are mutually coupled in non-inverting relationship; wherein the secondary winding and the tertiary winding are mutually coupled in inverting relationship; and wherein the tertiary winding is between the amplifier output and the second terminal.

Apparatus and methods for bias switching of power amplifiers are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, a power management circuit that controls a voltage level of a supply voltage of the power amplifier, and a bias control circuit that biases the power amplifier. The power management circuit is operable in multiple supply control modes, such as an average power tracking (APT) mode and an envelope tracking (ET) mode. The bias control circuit is configured to switch a bias of the power amplifier based on the supply control mode of the power management circuit.

Apparatus and methods for bias switching of power amplifiers are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, a power management circuit that controls a voltage level of a supply voltage of the power amplifier, and a bias control circuit that biases the power amplifier. The power management circuit is operable in multiple supply control modes, such as an average power tracking (APT) mode and an envelope tracking (ET) mode. The bias control circuit is configured to switch a bias of the power amplifier based on the supply control mode of the power management circuit.

A low-noise amplifier in a receiver supporting a beam forming function may selectively change a phase shift for beam steering. The low-noise amplifier may include first and second transistors and a variable capacitance circuit connected to a gate of the second transistor. The variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto according to beam-forming information, where the changed capacitance correspondingly causes a phase change in an output signal of the low-noise amplifier. A similar scheme may be employed for amplifiers in transmit signal paths to steer a transmit beam.

A low-noise amplifier in a receiver supporting a beam forming function may selectively change a phase shift for beam steering. The low-noise amplifier may include first and second transistors and a variable capacitance circuit connected to a gate of the second transistor. The variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto according to beam-forming information, where the changed capacitance correspondingly causes a phase change in an output signal of the low-noise amplifier. A similar scheme may be employed for amplifiers in transmit signal paths to steer a transmit beam.