An amplifier (T1) amplifies an input signal. A harmonic matching circuit (3) is connected to an output end of the amplifier (T1) via a first wire (W1). The harmonic matching circuit (3) includes a first inductor (L1) connected to the first wire (W1), a first capacitor (C1) connected in series to the first inductor (L1), a second inductor (L2) connected in parallel with the first inductor (L1), and a second capacitor (C2) connected in series to the second inductor (L2). The first inductor (L1) and the second inductor (L2) form a subtractive-polarity coupler which presents mutual inductance having subtractive polarity.

Circuits and methods for achieving good amplifier AM-AM and AM-PM metrics while achieving good power, PAE, linearity, and EVM performance. Embodiments compensate for a non-linear distortion profile (e.g., an AM-PM and/or AM-AM profile) in an amplifier by pre-processing an input signal, such as a radio-frequency signal, to alter the non-linear distortion profile of the input signal so as to compensate for the non-linear distortion profile imposed by a coupled device, such as an amplifier. An inventive aspect includes linearizing an output from an amplifier having a first non-linear distortion profile, including passing an input signal having a second non-linear distortion profile through a reflective hybrid coupler to a non-linear termination circuit, and reflecting a modified input signal from the non-linear termination circuit back through the reflective hybrid coupler as an output signal, the output signal having a third non-linear distortion profile shaped to compensate for the first non-linear distortion profile.

Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

Microwave amplifiers tolerant to electrical overstress are provided. In certain embodiments, a monolithic microwave integrated circuit (MMIC) includes a signal pad that receives a radio frequency (RF) signal, a ground pad, a balun including a primary section that receives the RF signal and a secondary section that outputs a differential RF signal, an amplifier that amplifies the differential RF signal, and a plurality of decoupling elements, some of them electrically connected between the primary section and the ground pad, others electrically connected in the secondary section to a plurality of the amplifier's nodes, and operable to protect the amplifier from electrical overstress. Such electrical overstress events can include electrostatic discharge (ESD) events, such as field-induced charged-device model (FICDM) events, as well as other types of overstress conditions.

Microwave amplifiers tolerant to electrical overstress are provided. In certain embodiments, a monolithic microwave integrated circuit (MMIC) includes a signal pad that receives a radio frequency (RF) signal, a ground pad, a balun including a primary section that receives the RF signal and a secondary section that outputs a differential RF signal, an amplifier that amplifies the differential RF signal, and a plurality of decoupling elements, some of them electrically connected between the primary section and the ground pad, others electrically connected in the secondary section to a plurality of the amplifier's nodes, and operable to protect the amplifier from electrical overstress. Such electrical overstress events can include electrostatic discharge (ESD) events, such as field-induced charged-device model (FICDM) events, as well as other types of overstress conditions.

A semiconductor device includes input and output terminals, first and second power supply terminals, first and second transistors, and a first resistance element. In the first transistor, gate and source terminals are respectively connected to the input terminal and the first power supply terminal, a drain terminal is connected to the second power supply terminal in direct current and to the output terminal, and the gate and drain terminals are connected via the first resistance element. In the second transistor, a source terminal is connected to the first power supply terminal, and gate and drain terminals are short-circuited at a node connected to the gate terminal of the first transistor in direct current. In a lower frequency region, an impedance of the first resistance element is lower than impedances of parasitic capacitances in the first transistor between the gate and drain terminals and between the gate and source terminals.

A semiconductor device includes input and output terminals, first and second power supply terminals, first and second transistors, and a first resistance element. In the first transistor, gate and source terminals are respectively connected to the input terminal and the first power supply terminal, a drain terminal is connected to the second power supply terminal in direct current and to the output terminal, and the gate and drain terminals are connected via the first resistance element. In the second transistor, a source terminal is connected to the first power supply terminal, and gate and drain terminals are short-circuited at a node connected to the gate terminal of the first transistor in direct current. In a lower frequency region, an impedance of the first resistance element is lower than impedances of parasitic capacitances in the first transistor between the gate and drain terminals and between the gate and source terminals.

A system and method which includes receiving an input signal and providing, by an amplifier circuit, an output signal in response to the input signal, the output signal having an envelope. An envelope detection signal corresponding to the envelope of the output signal is generated. A bias current provided to an amplifier circuit is adjusted based upon the envelope detection signal. The amplifier circuit includes an amplifier and a transformer, the transformer being configured to establish a magnetically coupled feedback loop from an output of the amplifier to an input of the amplifier.

A system and method which includes receiving an input signal and providing, by an amplifier circuit, an output signal in response to the input signal, the output signal having an envelope. An envelope detection signal corresponding to the envelope of the output signal is generated. A bias current provided to an amplifier circuit is adjusted based upon the envelope detection signal. The amplifier circuit includes an amplifier and a transformer, the transformer being configured to establish a magnetically coupled feedback loop from an output of the amplifier to an input of the amplifier.