V-BAND HIGH ISOLATION SUBHARMONIC MONOLITHIC MIXER WITH HAIRPIN DIPLEXER

Abstract

A 54{66GHz sub-harmonic monolithic passive mixer using the standard 0.15m pHEMT process is demonstrated. The proposed mixer is composed of a hairpin diplexer, an open stub, and a low-pass fllter. The mixer also utilizes a pair of anti-parallel diodes to achieve a subharmonic mixing mechanism. The hairpin diplexer formed with two parallel-coupled line band-pass fllters is used to improve the isolation between the radio frequency (RF) and local oscillation (LO) ports. The low-pass fllter supports an intermediate frequency (IF) ranging from dc to 1GHz. This proposed conflguration leads to a die size of less than 1.5mm 2 . With a conversion loss of 15.2{18.3dB, the 2LO- to-RF isolation is found to be better than 27.5dB. A high LO-to-RF isolation of 23.5{45dB over 54{66GHz RF bandwidth, as well as 1dB compression power of 8dBm, can be achieved.