小数分频技术解决了锁相环频率合成器中的频率分辨率和转换时间的矛盾, 但是却引入了严重的相位噪声,
传统的相位补偿方法由于对Aö D 等数字器件的要求很高并具有滞后性实现难度较大。$2 调制器对噪声具有整形的功
能, 因而将多阶的$2 调制器用于小数分频合成器中可以很好地解决他的相位噪声的问题, 大大促进了小数分频技术的
发展和应用。文章最后给出了在GHz 量级上实现的这种新型小数分频合成器的应用电路, 并测得良好的相噪性能。,Fractional-N technology to solve the PLL frequency synthesizer in the frequency resolution and conversion time of contradictions, but the introduction of a serious phase noise, the traditional method of phase compensation A? D because of the number of devices, such as demanding and have the lag is more difficult to achieve. $ 2 modulator with noise shaping function, and thus will be more than the $ 2-order modulator for fractional-N synthesizer can be a good solution to his problem of phase noise, contributed significantly to the fractional-N technology development and applications. Finally, the article in the GHz order to achieve this new fractional-N synthesizer of the application circuit, and measured a good phase noise performance.