A wireless repeater is disclosed. The wireless repeater can include a first gain unit with a first adjustable gain configured to be applied to a first-direction signal. The wireless repeater can include a second gain unit with a second adjustable gain configured to be applied to a second-direction signal. The wireless repeater can include a signal splitter communicatively coupled to the first gain unit and the second gain unit. The wireless repeater can include a control unit communicatively coupled to the first gain unit and the second gain unit. The control unit can control the first adjustable gain and the second adjustable gain to compensate for a signal loss of the signal splitter.

A PA module includes: a multilayer substrate having a ground pattern layer connected to a ground of a power source; amplifier transistors disposed on the multilayer substrate; a bypass capacitor having one end connected to the collector of the amplifier transistor; a first wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a second wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a third wiring line connecting the other end of the bypass capacitor and the ground pattern layer to each other; and a fourth wiring line formed between the amplifier transistor and the ground pattern layer and between the bypass capacitor and the ground pattern layer and connecting the first wiring line and the third wiring line to each other.

Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.

An amplifier applied to TIA is provided to suppress the noise caused by a current source. An amplifier constituting a transimpedance amplifier includes an inductor element inserted between a current source connected to an input terminal of an amplification stage and a power source voltage line. The current source includes a first transistor in which a base terminal is connected to a current control bias and a collector terminal is connected to the input terminal. The inductor element is inserted between the emitter terminal of the first transistor and the power source voltage line.

An amplification unit contains two or more sets containing a plurality of amplification circuits, and amplifies power of an RF (Radio Frequency) signal. A combining unit contains two or more combiners corresponding to the two or more sets, combines RF signals output by the amplification circuits, and outputs a resultant RF signal. The amplification unit and the combining unit have two or more connectors which are arranged transversely. The amplification unit and the combining unit are attachable/detachable.

A power amplification module includes first and second amplifiers for first and second communication modes, a bypass line that bypasses the first or second amplifier, an input switch circuit that supplies a radio frequency signal to the first or second amplifier in accordance with a communication mode when a desired output level is equal to or greater than a reference level, and that supplies a radio frequency signal to the bypass line when the desired output level is less than the reference level, and an output switch circuit that outputs a first amplified signal from the first amplifier or a second amplified signal from the second amplifier in accordance with the communication mode when the desired output level is equal to or greater than the reference level, and that outputs a radio frequency signal output from the bypass line when the desired output level is less than the reference level.

An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an amplifier circuit configured to amplify a radio frequency (RF) signal based on a modulated voltage. In examples discussed herein, the amplifier circuit is co-located with a local voltage amplifier circuit configured to supply the modulated voltage such that a trace inductance between the amplifier circuit and the local voltage amplifier circuit can be reduced to below a defined threshold. By co-locating the amplifier circuit with the local voltage amplifier circuit to reduce a coupling distance between the amplifier circuit and the local voltage amplifier circuit and thus the trace inductance associated with the coupling distance, it may be possible to reduce degradation in the modulated voltage. As a result, it may be possible to improve efficiency and maintain linearity in the amplifier circuit, particularly when the RF signal is modulated at a higher modulation bandwidth.

A new method for amplifying signals having higher bandwidth, lower T.H.D., higher efficiency, smaller circuit size and lower costs in design, has been developed. A clipped signal is amplified to smaller pieces and each smaller part is amplified. Adding clipped amplified signals to each other, the main amplified signal is generated.

A Doherty amplifier system is disclosed. The Doherty amplifier system includes a carrier amplifier having a main input for receiving a first portion of a radio frequency (RF) signal and a main output in communication with a RF signal output. A peaking amplifier has a peak input for receiving a second portion of the RF signal and a peak output in communication with the RF signal output. Further included is a first impedance inverter coupled between the main output and the peak output. A second impedance inverter is coupled between the peak output and the RF signal output. A first impedance inverter coefficient of the first impedance inverter is numerically within 10% of a second impedance inverter coefficient of the second impedance inverter.

A Doherty amplifier system is disclosed. A main amplifier is configured to receive a first portion of a radio frequency (RF) signal at a main input and provide an amplified copy of the first portion of the RF signal at a main output. A peaking amplifier is configured to be controllably activated to receive a second portion of the RF signal at a peak input and provide an amplified copy of the second portion of the RF signal at a peak output. A saturation detector has a detector input coupled to the main output of the main amplifier and a first detector control output, wherein the saturation detector is configured to detect saturation of the main amplifier and activate the peaking amplifier as saturation of the main amplifier is detected and deactivate the peaking amplifier when saturation of the main amplifier is not detected by the saturation detector.