A 4.32~8.64-GHz receiver front-end with variable gain amplifier and I/Q mixer for 60-GHz heterodyne system in 65nm CMOS technology

In this paper, a receiver front-end which contains variable gain amplifier (VGA) and Gilbert-cell-based I/Q mixer for 60-GHz heterodyne system in 65-nm CMOS technology is presented. The chip size is 0.91 × 1.515 mm², including all the testing pads and dummy metals. The operation frequency of the proposed receiver front-end is from 4.32 GHz to 8.64 GHz. At a 1.0-V supply voltage, this front-end demonstrates the gain-control capability at linear region from 2.5 dB to 12.5 dB by adjusting the control voltage of the attenuator in VGA. The measured P_sat is -11.7 dBm and it occurs at 2.5-dBm LO drive power where as RF frequency is at 7.48 GHz. The measured LO-to-IF and RF-to-IF isolation are better than 30 dB and 25 dB, respectively.