Broadband InGaAs PIN Traveling-Wave Switch Using a BCB-Based Thin-Film Microstrip Line Structure

This letter describes the design and fabrication of a broadband InGaAs PIN traveling wave switch. A new thin-film microstrip line structure integrated with InGaAs PIN diodes has been used to enhance the switch performance at higher frequencies. The developed InGaAs PIN switch has an insertion loss of less than 3.2 dB and an isolation of greater than 40 dB in a broadband frequency range from 25 to 95 GHz. The BCB-based multi-layer technology effectively reduces the chip size of the fabricated SPDT MMIC switch to 1.05 times 0.58 mm². To our knowledge, this is the first InGaAs PIN traveling-wave switch demonstrated up to 95 GHz.