Embodiments of a Doherty power amplifier that maintain efficiency over a large operating average power range are disclosed. In one embodiment, the Doherty power amplifier includes reconfigurable main and auxiliary output matching networks and a fixed combining network. The reconfigurable main and auxiliary output matching networks can be reconfigured such that together the reconfigurable main output matching network, the reconfigurable auxiliary output matching network, and the fixed combining network provide proper load modulation for multiple different back-off power levels. As a result, the Doherty power amplifier maintains high efficiency over an extended back-off power level range.

The present disclosure relates to systems and methods for operating transceiver circuitry to transmit or receive signals on various frequency ranges. To do so, a transmitter or a receiver of the transceiver circuitry is selectively coupled to or uncoupled from an antenna of the transceiver circuitry. Additionally, radio frequency filters may be individually or collectively coupled to and/or uncoupled from the antenna to filter different frequencies in the transmitting or receiving signals.

An apparatus includes: a transistor including an input terminal for an input signal and an output terminal for an output signal; a matching circuit configured to match a load impedance regarding a fundamental harmonic of at least one of the input signal and the output signal to an impedance of the transistor and include a first conductive film being laminated over the transistor and coupled to at least one of the input terminal and the output terminal; and a processing circuit configured to adjust an impedance regarding a harmonic of at least one of the input signal and the output signal and include a second conductive film being laminated over the first conductive film and coupled to at least one of the input terminal and the output terminal through a via which penetrates through a dielectric layer sandwiched between the first conductive film and the second conductive film.

Disclosed is an ultra low power transimpedance amplifier based on spintronics. According to the present invention, provided is an ultra low power transimpedance amplifier based on spintronics, which includes: a spintronics based oscillator receiving current and outputting an alternating signal by using spin transfer torque or spin orbit torque; a bandpass filter passing a signal in a predetermined frequency band of the alternating signal output by the spintronics based oscillator; and a spintronics based detector outputting voltage by inputting the signal in the predetermined frequency band, which is output by the bandpass filter.

A power amplifier circuit includes an amplification unit, a heating unit, and a control circuit. The amplification unit is configured to amplify a radio-frequency signal. The heating unit is provided adjacent to the amplification unit. The heating unit includes one or more transistors configured to generate heat that increases as the passing current increases. The control circuit is coupled to the one or more transistors. The control circuit is configured to increase the passing current when the environmental temperature is a predetermined threshold or lower.

The invention relates to a radio frequency assembly comprising a radio frequency circuit comprising at least one group of N≥2 amplifiers (A1, A2) disposed in series on a substrate (1), said assembly comprising a package (2) wherein the substrate (1) is disposed, each amplifier comprising a local grounding point (b1, b2, b3) and a local feed point (a1, a2, a3), said common grounding points being connected to a common ground (GND) outside the package (2), said common feed points being connected to a common power supply (VDD) outside the package, said assembly comprising at least N−1 parallel LC circuits disposed between the common power supply (VDD) and the local feed point (a2, a3) of an amplifier (A2) so as to attenuate the current loops between two amplifiers in series.

A power amplifier circuit includes a power amplifier that amplifies an input signal and outputs the amplified signal from an output terminal thereof, a first filter circuit that has a frequency characteristic that attenuates an Nth-order harmonic of the amplified signal, N that is an integer greater than or equal to 2, and a second filter circuit that has a frequency characteristic that attenuates the Nth-order harmonic of the amplified signal. The first filter circuit includes a first capacitor and a first inductor. The first capacitor and the first inductor are connected in series between the output terminal and ground. The second filter circuit includes a second capacitor and a second inductor. The second capacitor and the second inductor are connected in series between the output terminal and ground.

A power amplifier circuit includes a power amplifier that amplifies an input signal and outputs the amplified signal from an output terminal thereof, a first filter circuit that has a frequency characteristic that attenuates an Nth-order harmonic of the amplified signal, N that is an integer greater than or equal to 2, and a second filter circuit that has a frequency characteristic that attenuates the Nth-order harmonic of the amplified signal. The first filter circuit includes a first capacitor and a first inductor. The first capacitor and the first inductor are connected in series between the output terminal and ground. The second filter circuit includes a second capacitor and a second inductor. The second capacitor and the second inductor are connected in series between the output terminal and ground.

An amplifier is configured in such a way that a first capacitor resonates at the frequency of a second harmonic wave included in a signal outputted from an amplifying element, a circuit including a second transmission line, the first capacitor, and a second capacitor resonates at the frequency of a third harmonic wave included in the signal outputted from the amplifying element, and also matches the impedance for a fundamental wave together with an impedance matching circuit.

Methods related to power amplification systems with adjustable common base bias. A method of implementing a power amplification system can include providing a cascode amplifier coupled to a radio-frequency input signal and coupled to a radio-frequency output. The method can further include providing a biasing component configured to apply one or more biasing signals to the cascode amplifier, the biasing component including a bias controller and one or more bias components. Each respective bias component may be coupled to a respective bias transistor.