MONOLITHIC MILLIMETER-WAVE OPTICAL RECEIVERS

A single stage monolithic millimeter wave optical receiver circuit was designed and fabricated using a metal-semiconductor-metal (MS;Lf) pho todetector and a pSeudomorphic Modulation Doped Field Effect Transisto rs (SMODFET) on a GaAs substrate for possible applications in chip-to- chip and free space communications, The MSM photodetector and the SMOD FET epitaxial material were grown by molecular beam epitaxy (MBE). Dev ice isolation was achieved using an epitaxially grown buffer between t he MSM detector layers and SMODFET. The photodetector was designed for maximum absorption at optical wavelength of 770 mn light and the SMOD FET impedance matching network was optimized for 44 GHz. The monolithi c millimeter wave optical receiver circuit achieved 3 dB gain over a p hotodetector at 39 GHz, which was the limit of the measurement system, TOUCHSTONE model of the circuit indicated 6.6 dB gain over the photod etector and 5.7 dB total gain including the insertion loss of the phot odetector at 44 GHz.