DC-Feedback-Mode Transistor Rectifier/Voltage-Doubler Diode Rectifier for Negative Gate Biasing to Microwave Power Amplifiers

We propose a microwave power amplifier configuration in which a negative gate bias voltage is applied by a sub-mW rectifier, without a DC power supply for gate biasing. In this configuration, the small part of the RF power in the system, such as the small part of the local power in a transceiver, is used to generate the gate bias voltage. In the first trial of this concept, a zero-threshold GaAs HEMT rectifier with DC-feedback configuration and a voltage-doubler diode rectifier has been developed to obtain a sufficient voltage value. An absolute value of more than 1 V as a negative gate bias voltage was achieved with an input RF power of less than 1 mW for both rectifiers. In addition, each rectifier was successfully integrated into a GaAs HBT MMIC amplifier circuit, which was designed to be a driver amplifier in a wireless power transfer system.