Abstract: In this paper, the important characteristics of a High-performance FNPLL frequency synthesizer are discussed indetail.It outputs broadband frequency signal. The phase noise is -105dBc/Hz（fm＝1kHz），spurious electric level ＜-70dBc，andfrequency-hopping time ＜80μs.The operating temperature is -55～+70℃ with a volume of 98mm×72mm×15mm.Environmentaltest shows this synthesizer has stable working character.