一种短波数字收信机的频率合成器的实现方法

频率合成技术是短波收信机的重要技术之一。从频率合成的基本原理出发，通过比较分析各种合成器的实现方案，选择DDS＋PLL方案作为文章所介绍的短波数字收信机的频率合成器的实现方法。详细阐述实现该频率合成器所采用的关键技术，通过实际测试和对比对该方案进行评估。

Realization of a AGC in Short-wave Communication

Automatic Gain Control （AGC） is an important technology in digital shortwave receiver. This thesis is based on the basic theory and realization of AGC. In digital receiver, we pay more attention to the overload of A/D converter. In our digital AGC module, analogical signal is converted to digital signal by A/D converter, and then the control of gain is real- ized by the operation of sampled digital data. By the result of experiment, the digital AGE; designed by this method, which is characteristic of flat controlled response, fast speed of set-up time, low cost and simple circuit architecture. The implememted circuit module of digital AGC has been achieved large dynamic range at output signal level.