24GHz pulsed Doppler radar transmitter is presented, which is implemented with 0.13 um CMOS process. The transmitter include VCO, VCO buffer, Tx buffer and power amplifier, which produce pulses of very small duty with low power consumption. The measured transmitter phase noise of the VCO is -103 dBc/Hz, and the tuning range is 24 ∼ 25.4 GHz. The CW output power of power amplifier 10 dBm with 22% PAE. Implemented transmitter chip size was 1.06 mm × 0.98 mm.