This paper describes an ultra-wideband signal generator for FMCW radar application. The system is based on a charge pump phase-locked loop architecture and features a continuous tuning range from 6 GHz to 15 GHz combined with low in-band phase noise of -80 dBc/Hz and -105 dBc/Hz in average at 1 MHz offset to the carrier. The system utilizes a hybrid structure where the voltage controlled oscillator was fabricated using 130 nm SiGe BiCMOS technology and the lower frequency components are off-the-shelf. An FPGA enables different waveform generation in the frequency domain. The synthesizer is suitable to operate as an ultra-wideband, low phase noise, low cost and small signal generator for frequency domain waveform generation like frequency chirps for FMCW primary radar with ultra high range resolution. Core components power consumption amounts to 340 mW and the size of the system is 6 cm × 7 cm.