A 24‐GHz active up/down bidirectional mixer in 130‐nm RF CMOS

Abstract

An active bidirectional mixer based on modified Gilbert cell has been proposed to perform the up/down conversion at 24 GHz in a 130-nm RF CMOS. Employing the transconductance gm/load sharing stage, the mixer not only reduces the required power of local oscillator (LO) signal, but also increases the linearity and the conversion gain (CG). With a 2-dBm LO power, the mixer achieves measured CG of −1.7 dB, noise figure (NF) of 14.6 dB, and output 1-dB compression point (OP1dB) of −8.4 dBm at 24 GHz in the up-conversion mode. In the down-conversion mode, the mixer exhibits measured CG of 2.6 dB, NF of 15.9 dB, and input 1-dB compression point (IP1dB) of −0.1 dBm at 24 GHz. From 23 to 25 GHz, the measured LO-to-RF and LO-to-IF isolations (ISOs) are better than 55 dB and 48 dB, respectively. The chip area including all testing pads is 0.75 × 0.8 mm2, which consumes 10.5 mW from a supply of 1.5 V.