A 26–40GHz monolithic doubly-balanced mixer

This paper presents the design of a 26-40 GHz monolithically integrated doubly-balanced mixer for ultra-high speed wireless communication. A modified Marchand balun is used to expand the bandwidth. A coupled line of U section improves the port to port isolation and provides the IF-output port. Simulated in 0.15-mum GaAs PHEMT technology, the mixer achieves a low conversion loss of less than 8 dB and a high isolation of above 30 dB over a 26-40 GHz RF/LO bandwidth and a 8-14 GHz IF bandwidth.