Design of a low-voltage CMOS mixer based on variable load technique

Abstract

A CMOS active mixer based on variable load technique which can operate at 1.0V supply voltage is proposed and its operation principle is presented. The proposed mixer controls the load impedance according to the LO signal. It has only two stacked transistors at each branch, which is suitable for low-voltage applications. The mixer was designed in 0.18-µm CMOS process and measured in 2.4-GHz ISM band. With a 2.440GHz RF input signal and a 2.442GHz LO signal (4dBm), the conversion gain is 5.3dB, the input-referred third-order intercept point is 4.6dBm, the input-referred 1-dB compression point is -7.4dBm, and the single-sideband noise figure is 21.7dB. Current consumption is 3.5mA at 1.0V supply.