A fully integrated 24-GHz CMOS ultra-wideband (UWB) radar transmitter for short-range automotive application is presented. For high-range resolution and improved signal-to-noise ratio, a pulse compression technique using binary phase code is adopted. Design issues of UWB radar transmitter are investigated based on fundamental pulse theory. A pulse former, which operates as a switch to generate a pulse modulated carrier signal and a bi-phase modulator for pulse compression, is proposed. The proposed transmitter achieves 4-GHz output signal bandwidth, which means a minimum range resolution of 7.5 cm, and the total dc power dissipation is 63 mW.