GaAs MMIC´s for Digital Radio Frequency Memory (DRFM) Subsystems

A DRFM analog subsystem using ten GaAs MMIC chips (six limiting amplifiers, one quadrature down-converter, two IF amplifiers, and one quadrature up-converter) has been developed and integrated into a 0.72-cubic-inch module. The 2-6-GHz limiting amplifier provides 12 dBm constant output power, the quadrature IF mixer down-converts a 2-6-GHz input signal into two 1 MHz to 1 GHz quadrature IF signals, the IF amplifier provides the required gain, and a quadrature up-converter converts the IF signals to a 6-8-GHz output band. The input signal dynamic range is 50 dB. The amplitude and phase tracking performance of the two IF channels is +-0.5 dB and +-5°, respectively. The output signal is a single-sideband suppressed carrier signal. The sideband rejection is 20 dB and the LO to RF isolation is 27 dB.