Design of an absorptive MMIC switch for satellite communication system

A monolithic microwave integrated circuit (MMIC) switch chip is developed using the InGaAs/GaAs p-HEMT process for the switch matrix of a satellite communication system. An absorptive MMIC switch is designed for good reflection-coefficient performances of the input and output ports at both on- and off-states. A quarter-wavelength impedance transformer is realized with the lumped elements of an MIM capacitor and a spiral inductor at 3 GHz band in order to reduce the chip size. The MMIC switch covers the frequency range 3.2-3.6 GHz. According to the on-wafer measurement, the fabricated MMIC switch with a miniature size of 1.6 × 1.3 mm demonstrates insertion loss below 2 dB and isolation above 56.8 dB, and-the measured performance agrees well with the simulation results.