Design of a 220GHz 4X subharmonical mixer using terahertz GaAs Schottky diodes BITD1530A

In this paper, we present the design and optimization of a 220GHz 4X subharmonical mixer based on an antiparallel pair of planar GaAs Schottky diodes BITDA1530 from Beijing Institute of Technology, which is flip-chipped onto the 100 μm thick quartz microstrip circuit. The finline and E-plane probe waveguide to microstrip line transitions are adopted for coupling the RF and LO signal respectively. The optimized 4X subharmonical mixer exhibits that the double side band (DSB) conversion loss is below 25 dB over the range of 217-223 GHz, with the minimum of 21.5 dB under the LO level of 5 mW.