Abstract: A C-band transmit-receive module for an active aperture radar is provided employing gallium arsenide chips preferably manufactured by the Multifunction Self-Aligned Gate process and employing both open and closed loop error correction for both phase and amplitude to correct for errors due to temperature, power supply variations, operating bandwidth and phase states.In a second embodiment a power output amplifier is provided employing predriver, driver and power amplifier stages wherein the power amplifier or the power amplifier and the driver may be switched out of the circuit if not needed. The bias on the amplifier may also be lowered if not needed. This is done to increase efficiency and reduce temperature.In both embodiments class B amplifier are preferred.

Abstract: A radar phase shifter is described, of the type which includes several phase shift devices whose phase shift angles can be added together, which produces a minimal VSWR and an accurately controllable total phase shift. A five bit phase shifter includes devices that phase shift by angles that are nominally 11.25.degree., 22.5.degree., 45.degree., 90.degree., and 180.degree.. The 45.degree. device is located between the 90.degree. and 180.degree. devices to minimize the VSWR. In addition to the preset phase shift devices, an analog phase shifter device is provided which compensates for the inaccuracy of the other devices.

Abstract: A power amplifier having plural parallel amplification circuits of different gains selectively actuable to zero and maximum gains, and electronic switches to select a circuit for connection to a common output junction.