A low-loss high-isolation absorptive GaAs SPDT PIN switch for 24 GHz automotive applications

Design of a low-loss high-isolation absorptive GaAs SPDT PIN diode switch at 24 GHz is presented. The switch incorporates a total of 6 PIN diodes, i.e., 3 diodes in each arm. Two of the diodes are for high isolation purposes and the third diode provides the matched load to the isolated port. The measured insertion loss and isolation are better than 1.4 dB and 47 dB, respectively, in the frequency band 22 to 26 GHz. The input and output return losses are better than 12 dB in the same frequency band