A 5.2-GHz SiOe BiCMOS stacked-LO-stage CMFB (common mode feedback) subharmonic mixer is demonstrated in this article. The stacked-LO-stage and the active loads are used to improve the 2LO-RF isolation and the conversion gain, respectively. The SiGe mixer includes five levels of transistors stacked together at the supply voltage of 3.3 V because of the low knee-voltage characteristic of the SiGe HBTs (heterojunction bipolar transistors). The mixer demonstrated achieves 23 dB conversion gain and - 78 dB 2LO-RF isolation.
- 2LO-RF isolation
- Gilbert mixer
- SiGe heterojunction bipolar transistor (HBT)
- Subharmonic mixer