Design and Simulation of Down Conversion Mixer for LoRa Band IOT System

A down conversion mixer is designed and simulated for 866 MHz LoRa band IOT system in 180 nm CMOS technology. Designed Mixer uses Gilbert Cell as a mixer core. Inductive source degeneration technique is employed for improving the linearity of Gilbert cell and Pi type matching is used at RF transconductance stage for matching the input RF signal. Diode connected active load is used to improve the conversion gain. Mixer is simulated with Advanced Design System software. Simulated maximum conversion gain is 17.96 dB, P1dB compression point is -24.30 dBm, the value of S11 is -10.043 dB, and SSB noise figure as 8.225 dB.