A 1-8 GHz MMIC down-conversion mixer with input/output active baluns using SiGe HBT process

A 1-8 GHz MMIC down-conversion mixer for RF receiver is designed and fabricated using 0.8 μm SiGe HBT process technology. This mixer is implemented on chip using RF/LO wideband matching circuits, RF/LO input balun circuits, and IF output balun circuit. The measured results of the fabricated mixer show positive power conversion gain from 1 GHz to 8 GHz, bandwidth of 4.5 GHz, LO isolation (LO to RF isolation and LO to IF isolation) between -40 dB and -60 dB, IIP3 between 0 dBm and -4 dBm, current consumption of 21 mA for 3.0 V supply voltage. The chip size of the fabricated mixer is 1.9 mm × 1.3 mm.