An 18 to 40GHz Double Balanced Mixer MMIC

This paper describes the design and evaluation of a broadband, passive mixer IC. The RF frequency range is 18 to 40 GHz, the LO 20 to 42 GHz and the IF 0.1 to 17 GHz. A double balanced passive topology is used, which functions well as either an upconverter or a downconverter. The RF and LO ports are single-ended and the IC incorporates on-chip baluns to provide the differential interfaces with the double balanced mixer. The IF interface to the MMIC is differential. The IC was fabricated on the PP15-20, 0.15mm gate length PHEMT process of WIN Semiconductor. With an LO drive of +10dBm the mixer has a measured conversion loss of between 7dB and 10dB, depending on frequency. LO to IF rejection is > 30dB.