100 kHz~6 GHz宽带接收机设计

100 kHz-6 GHz broadband receiver design

摘要:

为解决射频信号接收系统前端因强电磁干扰而发生的互调干扰、阻塞和饱和等问题，设计基于宽带匹配网络优化了一款高效率宽带接收机。该接收机模块工作频率覆盖整个S波段，其采用4线制SPI接口，根据上位机的指令完成链路控制。除此之外，采用7阶巴特沃斯低通滤波器设计，严格保证带内最佳平坦度和端口驻波比。实测结果表明，该接收机模块实现了100 kHz~6 GHz的信号放大和下变频，并以140 MHz和100 kHz~19.999 MHz的中频输出，具备内外部10 MHz参考时基自动切换功能。可见射频接收前端优化设计可实现对目标侦测频段内信号的高选择性跟踪预选，使接收系统对强干扰信号进行有效抑制。

Abstract:

A high-efficiency broadband receiver based on broadband matching network is designed in order to solve the problems of intermodulation interference, blocking and saturation caused by strong electromagnetic interference at the front end of RF signal receiving system. The operating frequency of the receiver module covers the entire S-band, and it adopts a 4-wire SPI interface to complete link control according to the instruction of the host computer. The 7th-order Butterworth low-pass filter design is utilized to ensure the best flatness and port standing wave ratio in the band. The measured results show that the receiver module realizes signal amplification and down-conversion of 100 kHz-6 GHz, and outputs with intermediate frequency of 140 MHz and 100 kHz-19.999 MHz. It bears the internal and external 10 MHz reference time base automatic switching function. This module provides a single-ended 10 MHz clock for baseband board for baseband digitization. It shows that the optimized design of the RF receiving front end can achieve high selective tracking and pre-selection of signals in the target detection frequency band, so that the receiving system can effectively suppress the strong interference signal.