A high gain CMOS down conversion mixer with a gain enhancement technique is presented. This technique includes negative resistance generation, parasitic capacitance cancellation and current-injection. These are implemented with an additional circuitry. This mixer has a conversion gain of 9.12 dB, input 1 dB compression point of -11 dBm at 24 GHz, while consuming 16.2 mW from 1.8 V supply. Between 22 and 26 GHz, the LO-to-RF and RF-to-LO isolations are better than 35 dB and 26 dB, respectively.