电可调中频带通滤波器的设计
本文主要介绍了变容二极管实现的电可调中频带通滤波器的设计。利用变容二极管在反向偏压作用下电容变化的原理，设计变容二极管压控电路并加入带通滤波器电路中，通过改变电压值来改变变容二极管的输出电容，从而改变带通滤波器的带宽。通过对ADS软件的学习，在软件中设计电路并仿真，得到符合要求的滤波器幅度响应曲线。
本次设计要求运用微波固态电路知识，设计一个电可调中频带通滤波器，工作频率：140MHz，带宽：10MHz(带宽可调)。21115
关键词 带通滤波器 变容二极管 带宽 仿真
毕业论文设计说明书（论文）外文摘要
Title Design of Electrically Tunable Intermediate-frequency Band-pass Filter
Abstract
In modern communication system,especially in the field of military,frequency changing and hopping technology has got great development.As a kind of new filter,the tunable filter has got great attention of the researchers at home and abroad.
This paper mainly introduces the design of the electrically tunable intermediate-frequency band-pass filter achieved by the varactor.using the principle that the capacitance of the varactor changes under reverse bias voltage,we design voltage controlled varactor circuit and put it in the band-pass filter circuit. We change the bandwidth of the band-pass filter by changing the output capacitance of the varactor ,which was controlled by the voltage.Based on the study of ADS ,we design and simulate the circuit on the software to achieve the required amplitude response curve of the filter.
This design requires the use of the knowledge of microwave solid state circuit to design a electrically tunable intermediate-frequency band-pass filter.Its working frequency is 140MHz and bandwidth is 10MHz,which is tuable.
Keywords bandpass-pass filter varactor bandwidth simulate
目 次
1 绪论 1
1.1 滤波器的研究和发展历史 1
1.2 可调滤波器的研究背景和研究现状 2
1.3 本文的章节安排 3
2 带通滤波器的设计 5
2.1 本次设计的整体思路 5
2.2 低通滤波器的设计原理 6
2.3 低通滤波器到带通滤波器的转化 8
2.4 定K型带通滤波器的设计 9
2.5 电容耦合谐振器式带通滤波器的设计 11
2.6 本章小结 15
3 ADS基本知识和仿真介绍 16
3.1 ADS简介 16
3.2 ADS的仿真步骤和要点 17
3.3 本章小结 18
4 变容二极管 19
4.1 变容二极管基本特性 19
4.2 变容二极管用途 20
4.3 变容二极管型号选择和VC特性测试 20
4.4 本章小结 24
5 变容二极管实现电可调带通滤波器 25
5.1 变容二极管电路置换耦合电容 25
5.2 变容二极管压控电路的接入方法 25