Dynamic Current Injection Technique for Improving Linearity and Gain in Gilbert Cell Mixer

This brief presents a highly linear, high gain Gilbert cell mixer in 0.18μm CMOS technology. To improve the linearity and gain, dynamic current injection technique is used. For this, a PMOS cross coupled pair is connected at the IF stage of the mixer to inject the current dynamically into circuit. The mixer operates with a RF frequency of 2.4 GHz. The simulation results of the proposed Gilbert cell mixer with current injection technique gives third order input intercept point (IIP3) of 5.8 dBm, conversion gain of 9.9 dB and noise figure of 3.6 dB. The power consumption is 4mW with a supply voltage of 1.8 V. Analysis on the variation of gain and linearity with temperature is also presented.