Low noise design of a CMOS Gilbert mixer cell in 700 MHz

A design of a MOS Gilbert mixer cell intended for LTE band 28 is presented in this work. The objective is directed to a design with low noise and low third-order intermodulation distortion. The designed mixer can be used in a fully-differential chain, avoiding the implementation of a balun. Since the overall IP3 of a full front-end depends on the IP3 of the each stage, specially those behind the low-noise amplifier (LNA), it is mandatory to have a properly designed mixer. In this design a CMOS 0.18 μm process is employed. The proposed scheme allows to obtain the following characteristic parameters: an IIP3 of 8.69 dBm, a 1dB-compression point of -1.28 dBm, a noise figure of 8.2 dB and draw 30 mA from a 3.3 V power supply.