A $Ka$ -Band GaAs MMIC Traveling-Wave Switch With Absorptive Characteristic

A 36-38-GHz monolithic microwave integrated circuit (MMIC) single-pole double-throw (SPDT) switch employing a traveling-wave concept with absorptive characteristic is presented. The switch uses absorptive sections for better impedance matching in all ports. The switch obtained good linearity with the insertion loss of 3.2 dB, more than 28-dB isolation, and the return losses at all the ports are larger than 8.1 dB within the bandwidth of interest (36-38 GHz). The switch was fabricated by using GaAs 0.15-μm process. The chip area is very compact, just about 1 mm × 1.1 mm, including all the pads. To our best knowledge, this is the first GaAs MMIC traveling-wave switch type that has the absorptive characteristic.