Characteristics of SiGe device fabricated by SiGe BiCMOS technology and its application to a 5.8 GHz MMIC down-conversion mixer

In this paper, a 5.8 GHz MMIC down-conversion mixers are designed and fabricated on chip using SiGe BiCMOS process technology. To fabricate a SiGe HBT, we use a RPCVD system to grow a base epitaxial layer, and have adopted LOCOS isolation to separate the device and device terminals. This mixer is integrated on chip with RF/LO matching circuits, RF/LO input balun circuits, and IF output balun circuit. The measured results of the fabricated mixer show conversion gain of 5.5 dB, LO to RF isolation of 44 dB, and LO to IF isolation of 40 dB, IIP3 of 1.8 dBm. The chip size of the fabricated mixer is 1.9 mm /spl times/ 1.2 mm.