This paper introduces the design of an ultra-wideband frequency agility Source, The Source is synthesized by direct simulation, and the ultra-wideband, frequency agility, the low phase noise, the low spurious are realized by reasonable frequency division and high performance switching filter technology, and then the final test results are given. According to the experimental results, the system performance is listed for reference: the output frequency covering the full Ku band, the hopping time is less than 200 ns, the phase-noise performance is better than -103 dBc /Hz@ 1 kHz and the spurious performance is better than -70 dBc.