宽带接收机应用的超宽倍频程电调滤波器设计*

电调谐预选滤波器是宽带接收机的关键部件,直接影响到整机性能的好坏。设计了一种采用梳状滤波结构的电调滤波器,工作频段为200~600MHz,整个调谐范围内,1d B带宽约为12%,插入损耗小于3d B,输入二阶截点值大于60d Bm,输入三阶截点值大于20d Bm,输入输出端口驻波比小于1.8,测试和仿真结果吻合良好。该滤波器结构简单、体积小、工艺上易实现,还具有超宽倍频程的调谐范围及低插损、高截点值等优良电性能。

Design of Ultra Octave Tunable Filter for Wide Band Receiver Applications

Tunable pre-select filters are crucial components in wideband receiver, which directly effects on receiver performance. In this paper,a comb-shaped tunable filter is presented. The filter operates over a band width from 200MHz to 600MHz. The filter exhibits a 1dB band about 12%, insertion loss less than 3dB ,IIP2 more than 60dBm,IIP3 more than 20dBm,VSWR less than 1. 8 at both input and output port across the 200 ~600MHz band. The simulated results are good agreement with the measured ones. And also,this design has a relatively simple structure which is easy to implement in technology. In addition, this design exhibits excellent electrical properties such as ultra ovtave tuning range,low insertion loss,high IP2 and IP3.