直接加间接锁相调频应用于TV伴音调频

Direct and indirect PLL FM and application in TV voice FM

本文分析了锁相调频的原理,指出了直接锁相调频应用于TV伴音调频的缺陷。同时分析了直接加间接锁相调频应用于TV伴音调频的优点,即既可以克服伴音漂移现象,又可以扩展调制频率下限。笔者最后给出了具体设计实例和测试参数。

This paper analyzes the theory of Phase locke loop frequency modulation(PLL FM) and points out the shortcoming of the direct PLL FM when it is applied inTV voice FM, as well as analyzes the excellences of the direct and indirect PLLFM when it is applied in TV voice FM, that is, it not only can overcome theshift of voice signal, but also can spread lower limit modulation frequency. Atlast, author in the paper gives a designing example and measured parameters.