In the ultra-wideband radar system, the chaotic pulse position modulation (CPPM) signal is usually composed of Gaussian pulse sequences with chaotic changes at time intervals. For the problem of low radiation efficiency of Gaussian pulses, a modulation pulse is designed as a single-cycle pulse. Ultra-wideband CPPM signal source. Firstly, the digital simulation verifies the feasibility of Tent mapping as a modulation function. Then, using the FPGA module and the analog circuit module with step recovery diode (SRD) as the core, the main pulse width is 590 ps, the main peak value is -1.76 V and the waveform is obtained. The autocorrelation operation results show that the signal has good anti-interference ability and high detection probability; the spectrogram shows that the signal has no DC component and has very little energy in the low frequency region. When used as the radar signal, the radar can effectively improve the radar. Radiation efficiency of the antenna.