Design of a novel UTC-PD-array’s structure for power combining above 110GHz

A novel uni-traveling-carrier photodiode (UTC-PD) array’s structure for power combining above 110GHz was designed and fabricated to extend a single PD’s power limit in the THz regime. Four identical monolithically integrated UTC-PDs’ power was combined with T-junctions connecting every 6.5µm-diameter anode of these InGaAs-InP PDs. All PDs and combiner were fabricated on a 12µm-thick InP substrate, and the fulfilled chip was then measured after flip-chip bonding on a 50µm-thick AlN-based coplanar waveguide circuit. A continuous wave output power 0.19mW was measured at an operating frequency of 112GHz with a bias voltage of -3V.