Photoconductive semiconductor switches with microlens array trigger assembly

This proposal aims to develop a high-efficiency single pole double throw (SPDT) photoconductive semiconductor switch (PCSS) microwave switch employing wide bandgap GaAs and an innovative microlens array optical delivery assembly and anti-reflection (AR) coating designed to generate multi-filament conduction channels to boost the maximum current supported by devices. The microlens array is designed to maximize light coupling and photoconductivity while the patterned chip will utilize a reflective coating to further increase device efficiency and reduce the total optical power required for conductivity sufficient for microwave propagation. The SPDT device topology will consist of a broadband equal split microstripline lossless T-junction power divider, where the patterned GaAs chip introduces an open circuit at the output ports for isolation enhancement. The device will be designed to cover 2-12GHz with a threshold power of 250W at 3GHz and 50W at 10GHz. The target insertion loss will be less than 1dB and isolation greater than 20dB. The device and supporting components will be designed to achieve switching speeds faster than 500 us with greater than 20% duty cycle, more than 3e9 cycles, and an IIP3 10dB above P1dB.