Abstract: A communication device (104) includes a radio frequency power amplifier (202) and a bias circuit (204). The power amplifier (202) includes a depletion mode MESFET (214) for RF power amplification. To properly bias the MESFET (214) in a circuit including logic components powered by a conventional battery (136), the bias circuit (204) includes a level shifter (223) to provide the necessary gate-to-source voltage for the MESFET (214). To maintain the RF output power from the communication device (104) constant over temperature, the bias circuit (204) output voltage varies over temperature to track the temperature variation of the MESFET (214).

Abstract: A two dimensional distributed amplifier phase shifter having a distributed reference amplifier circuit generating a reference signal, the reference amplifier circuit having its input connected to one end of a plurality of serially connected microstrip transmission lines. The phase shifter further has a plurality of phase shifted amplifier circuits, one associated with each of the microstrip transmission lines. Each phase shifted amplifier circuit has an input connected to an end of its associated microstrip transmission line which is opposite the reference amplifier circuit and generates an output signal, phase shifted from the reference signal or the output signal of an adjacent phase shifted amplifier by a predetermined phase angle. The phase shifter may be fabricated as a monolithic microwave integrated circuit.