DC offset and high flicker noise are the main problems for the direct conversion CMOS mixer design. A novel even harmonic switching mixer implemented in a standard 0.18 μm CMOS process for applications in 2.45 GHz direct conversion receivers is proposed. The mixer circuit overcomes the problems of DC offset and high flicker noise. It achieves -8.24 dB gain, 5.2 dB DSB noise figure at 100 KHz, 17.25 dBm IIP3 and zero DC power consumption.