Abstract: A method for amplifying an RF signal is provided. The method includes providing the RF signal to an input of a quadrature coupler. The method includes outputting, from the quadrature coupler, a carrier path signal and a peak path signal. The method includes amplifying the carrier path signal to provide an amplified carrier path signal and amplifying the peak path signal to provide an amplified peak path signal. The method includes generating a first neutralizing signal based on the carrier path signal and generating a second neutralizing signal based on the peak path signal. The method includes modifying the amplified peak path signal based on the first neutralizing signal to provide a neutralized peak path signal and modifying the amplified carrier path signal based on the second neutralizing signal to provide a neutralized carrier path signal. The method also includes combining the neutralized carrier path and peak path signals.

Abstract: A circuit includes: an RF amplifier including RF transistor(s); a DC power source electrically coupled to the RF amplifier; a bias control input that receives a bias control signal from a bias control circuit electrically coupled to the DC power source; and a thermal tracking circuit located at a distance from the RF transistor(s) such that RF interference between the RF transistor(s) and the thermal tracking circuit is below a threshold during circuit operation. The thermal tracking circuit includes heating element(s), a DC bias reference device, and a thermal tracking control circuit electrically coupled to the DC power source and the heating element(s). The thermal tracking control circuit generates a signal that controls a thermal behavior of the heating element(s). The heating element(s) heat the DC bias reference device when activated. The DC bias reference device is electrically coupled to the bias control input to modulate a bias voltage.

Abstract: Radio-frequency amplifier circuit including: a first matching circuit; a driver stage circuit, in which the first matching circuit is coupled to the driver stage circuit, and in which the first matching circuit is configured to transform an input impedance of the driver stage circuit into a first impedance at an input to the first matching circuit; an inter-stage matching circuit coupled to the driver stage circuit; an output stage circuit coupled to the inter-stage matching circuit, in which the inter-stage matching circuit is configured to transform an input impedance of the output stage circuit into a second impedance at an output of the driver stage circuit; and and a second matching circuit coupled to the output stage circuit, in which the second matching circuit is configured to transform an impedance at an output of the second matching circuit into a third impedance at the output of the output stage circuit.

Abstract: A radio-frequency (RF) push-pull amplifier circuit that includes: a first transistor; a transformer; and a first matching circuit comprising at least one capacitor and at least one inductor, in which an input of the first matching circuit is coupled to an output of the first transistor, an output of the first matching circuit is coupled to an input of the transformer, and the first matching circuit is configured to transform an impedance at the input of the transformer into a first predefined impedance at the output of the first transistor.