A new high frequency CMOS current-mode up-conversion mixer is proposed to realize the transmitter front-end in the frequency band of 24 GHz. The transmitter integrates with a double-balance current-mode up-conversion mixer, an IF amplifier/repeater, a differential VCO and a differential VCO buffer/repeater. The performance of the transmitter exhibits a conversion gain of 1.3 dB, the input 1-dB compression point (P-1dB) is -22 dBm, the input intercept 3rd-order compression point (PIIP3) is -8.75 dBm, and the output intercept 3rd-order compression point (POIP3) is -7.44 dBm. The phase noise of the differential VCO is -117 dBc/Hz at 10-MHz offset from 26 GHz. The proposed mixer consumes only 3.89 mW from a 1-V supply. The total power dissipation of the transmitter is 15.4 mW from 1-V supply. This chip is designed in 0.13-μm 1P8M CMOS technology and under fabrication.