摘要
针对大动态范围高灵敏度短波接收机射频前端信号处理需要,提出并实现了一种基于CPLD的开关电容组式跟踪滤波器与变容二极管电调谐滤波器串联方案,并对该滤波器性能进行了评估。实验结果表明,该滤波器可以工作于1MHz^30MHz频段,带宽易调,设计简单,且具有稳定的带宽和很高的温度稳定性。实测的滤波器3dB带宽为300kHz^700kHz,Q值为11.8dB^25dB,通带增益为2.5~4.5,能很好地满足接收机设计指标。
According to the RF fi'ont-end needs of the large dynamic range and high sensitivity shortwave receiver, this paper proposes a design method of the switch-capacitor-group-style tracking filter based on CPLD and the varactor electric tuned filter in series. Then it makes a performance evaluation of the tracking filter. The experimental results indicate that the tracking filter can work well on the frequency band between 1 MHz to 30 MHz. The experiment also shows that the design provides a stable band width and higher temperature stability. The observed data of the filter shows that the 3 dB bandwidth is 300 kHz to 700 kHz, with high Q value of 11.8 dB to 25 dB, and the passband gain is 2.5 to 4.5. The experimental results can meet the design indicators of the receiver very well.
出处
《微型机与应用》
2013年第3期19-22,共4页
Microcomputer & Its Applications
基金
国家自然科学基金仪器专项(41127003)
湖北省自然科学基金重点项目(2010CDA062)
国家科技基础性专项重点项目(2008FY120100)
关键词
CPLD
开关式电容
跟踪滤波
短波
CPLD
switch-capacitor-group-style
tracking filter
shortwave