Abstract: An RF power amplifier utilizes predistortion to improve linearity of the amplifier. RF carrier signals from an input terminal are coupled to a power amplifier through a first amplitude and phase adjustor serially connected with a predistortion amplifier having signal distortion characteristics of the power amplifier. A first control loop includes a subtractor for receiving RF carrier signals from the input terminal and signals from the predistortion amplifier and producing a predistortion signal for applying to the power amplifier through a path including a second amplitude and phase adjustor and an error amplifier. A first loop control unit receives the RF carrier signals from the input terminal and the distortion signal and produces control signals for the first amplitude and phase adjustor for minimizing RF carrier signals in the predistortion signal.

Abstract: A monolithic microwave integrated circuit switch includes a series field effect transistor having a source drain path in series with an inductive transmission line including plural taps. Source drain paths of plural shunt field effect transistors are connected to the taps. The source drain paths of the series and shunt transistors are biased so that the series and shunt source drain paths have complementary low and high impedance states. The high impedance state is capacitive, having a value on the order of magnitude of the inductive transmission line. During a first time interval, the capacitive and inductive impedances form a matched low pass filter to supply current from a microwave source to a load. During a second time interval, current from the microwave source flows through the shunt field effect transistors to be decoupled from the load.