A High Gain and Low Noise CMOS Gilbert Mixer with Improved Linearity Based on MGTR and Switched Biasing Technique

This brief presents the design of an improved linear Gilbert mixer with high conversion gain and low noise figure by using multiple gated transistor (MGTR) and switched biasing technique. This mixer operates at a radio frequency (RF) of 2.4GHz with a local oscillator (LO) power of 5dBm in UMC 180nm process. The MGTR method is used to increase the linearity of the proposed mixer by the parallel combination of transconductance stage transistors and auxiliary transistors. The switched biasing technique is adopted for a current source instead of static biasing which lowers the noise figure. The integration of two techniques result in a conversion gain (CG) of 10.9dB and a noise figure (NF) of 7.2dB with the third order input intercept point (IIP3) of 10.79dBm. This proposed mixer circuit consumes 4.2mW power from a supply voltage of 1.8V.