A MMIC double balanced diode ring mixer in GaAs

This paper presents a monolithic microwave integrated circuit (MMIC) double balanced diode ring mixer. This chip fabricated in the 0.15 μm pHEMT GaAs process which is offered by WIN Semiconductor. Spiral structure of Marchand balun is used to minimize the chip's size. This mixer design achieves a low conversion loss of 5 to 6 dB and high LO-RF isolation of average 45 dB over the RF/LO bandwidth which is 15-25 GHz and a DC-2 GHz IF. This mixer also obtains good linearity with IIP3 of more than 20 dBm. The chip's size included build in Marchand balun is around 0.75 mm
²
.