Low-loss high-isolation 60-80 GHz GaAs SPST PIN switch

A low-loss high-isolation GaAs SPST PIN diode switch for millimeter wave applications is presented. Modeling of PIN diode switches using full-wave electromagnetic simulators by including the semiconductor properties of the diode mesa layers is explained. This approach eliminates the necessity of model extraction from measurements in most cases. In addition, usage of simulation tools allows the optimization of diode structure for minimum insertion loss. Main loss mechanisms of GaAs PIN diodes at mm-wave frequencies are explained. Measurement results of a newly developed CPW SPST 55-85 GHz GaAs PIN switch are presented and compared with simulations. The developed shunt switch has 0.6 dB insertion loss and 20 dB return loss in the off state (through) at 75 GHz. It has 20 dB insertion loss and 1 dB return loss in the on state (isolation) at the same frequency.