Using the technologys of direct digital synthesize, fractional-N phase-lock loop, high speed digital frequency and phase detector, lower noise loop filter, the technology of PLL signal source at lower phase noise and clutters is greatly improved. 该方案利用直接数字合成、小数分频锁相、高速数字鉴频鉴相、低噪声环路滤波等频率合成技术来降低相位噪声、杂散和提高分辨力,使合成信号源整机的各项技术指标均有较大提高。