FET amplifier

About: FET amplifier is a research topic. Over the lifetime, 7048 publications have been published within this topic receiving 77549 citations.

Load driver with reduced dissipation under reverse-battery conditions

Abstract: A relay-less load driver circuit includes an FET that couples a battery to a load. A bias circuit that selectively turns the FET on during normal operation also turns the FET on in reverse-battery conditions to avoid high power dissipation by an intrinsic diode associated with the FET.

High power FET switch

Abstract: In an FET switch for controllably allowing and inhibiting passage of an input signal in ON state and OFF state, respectively, FETs are connected in a multi-stage configuration. A control voltage adjusting circuit is connected between a gate and one of a drain and a source of each FET. The control voltage adjusting circuit adjusts a gate-source voltage so as to follow the variation of a drain-source voltage. The input voltage applied to the FET switch in OFF state is divided by the plurality of FETs. Since the variation of the gate-source voltage follows the variation of the drain-source voltage, the FET switch is hardly influenced by an amplitude of the input signal.

Multi-band high-efficiency doherty amplifier

Abstract: The present invention relates to a Multi-Band Doherty amplifier. Embodiments of the present invention provide an amplifying structure including a main amplifier configured to amplify a first signal, a peak amplifier configured to amplify a second signal, a tunable impedance inverter configured to perform impedance inversion to modulate a load impedance of the main amplifier, and a combining node configured to receive the amplified second signal from the peak amplifier and an output of the tunable impedance inverter. The tunable impedance inverter includes a tuner configured to tune the impedance inversion over at least one broad frequency band. The tuner is (i) at least one capacitor, (i) at least one varactor, or (ii) at least one open stub shunted by a diode.

Millimeter-Wave Power Amplifier Based on Coaxial-Waveguide Power-Combining Circuits

Abstract: A millimeter-wave power amplifier based on a coaxial-waveguide power-combining circuit is presented in this paper. A coaxial stepped impedance transformer is used to provide an impedance transition from the 50-? input coaxial line to the oversized coaxial waveguide, and its equivalent-circuit model has also been developed. A Ka-band four-device coaxial-waveguide power amplifier is fabricated and tested. The 10-dB return loss bandwidth of the fabricated amplifier is from 27.5 to 40 GHz, and the power amplifier has 17-25.9 dB gain over a wide bandwidth from 26 to 38 GHz. The measured output power at 1-dB gain compression is about 26.6 dBm at 30 GHz, with a power-combining efficiency of about 90%.

Radio frequency amplifier with reduced intermodulation distortion

Abstract: Apparatus and methods of broadband amplification with high linearity and low power consumption are described. An apparatus configured to amplify a signal includes an input transistor and an output transistor coupled together in a cascode configuration with the input transistor defining an input of the amplifier and the output transistor defining an output of the amplifier. A feedback network is coupled between the input and the output and is characterized by an impedance of substantially zero resistance and non-zero reactance. A method of amplifying a signal is also described. An input signal is received at an input; the input signal is amplified to provide an output signal at an output; and the output signal is sampled at the input through a feedback network characterized by an impedance of substantially zero resistance and ion-zero reactance. A method of making an apparatus configured to amplify a signal is also described.