A 25-to-70 GHz and low LO power mixer using modified SiGe NMOS-HBT Darlington cell for Gigabit BPSK demodulation

A binary phase shift keying (BPSK) demodulator using 0.18-μm SiGe process is presented in this paper. A hybrid modified SiGe NMOS-HBT Darlington cell is proposed for the circuit design. The driving LO power is further reduced as compared to the conventional Gilbert-cell and Darlington-cell mixers. This work exhibits a broad RF bandwidth from 25 to 70 GHz with a lower driving LO power of -1 dBm, a maximum conversion gain of 0 dB, and a data rate of 1.5 Gbps. This is the first attempt to demonstrate a broadband low LO power mixer using SiGe NMOS-HBT Darlington cell for BPSK demodulation.