基于FPGA和AD8318的预/后选器自检电路设计应用

Design and Application of an Auto-test Circuit for Pre/Post-selector Based on FPGA and AD8318

预/后选器是一种用于短波跳频电台内接收机和发射机的数字调谐跳频滤波器,是大型通信系统中的一个重要组成部分。为了方便测试预/后选器,提出一种基于XC3S200A FPGA和AD8318检波器的自检电路。首先由FPGA PLL模块产生能覆盖所有谐振电路的频率组作为自检信号,然后将通过预/后选器的自检信号送入AD8318检波器检验其增益是否达标。实验结果表明,该自检电路能有效实现对预/后选器各通道性能的快速检验与准确分析,对于及时锁定故障通道具有重要意义。

Pre/post selector is a digital tunablefrequency hopping filter for shortwave frequency-hopping radio receivers and transmitters.It is an important part of large communication systems.A self-test circuit based on XC3S200A FPGA and AD8318 detector is proposedto facilitate the test of pre/post selectors.First,the FPGA PLL module generates a series of self-test signals withfrequencies covering all the resonant circuits,and then the gain of each output signal from the pre/post selector is detected by the AD8318 detector for further testing.The experimental results show that this self-test circuit can check quickly and analyze accurately the performance of each channel in the pre/post selector,which is of great significance for determining the faulty channel as soon as possible.