提出了一种新颖的基于低通滤波控制特性的AFC系统,使用低通滤波器的过渡带代替传统的中频鉴频器的鉴频特性曲线,将由于各种因素造成发射机频率不稳的频率偏差转化为符号函数,结合DDS技术,从而形成一种宽频率跟踪范围的AFC系统.

A novel AFC system based on the control performance of a low pass filter is presented in this paper. The transition band of the low pass filter is used instead of the characteristic curve of an IF frequency discriminator. The frequency deviation of the transmitter due to various causes is converted into a sign function. These together with the DDS technique are used to form an AFC system with a wide frequency tracking range.

TN95