具有宽频段共模抑制的四端口平衡滤波电路
毕业论文关键词 带通滤波器（BFE）、 差分/共模、 半波长、 开路短截线、 宽带
外文摘要
Title Four port balance filter circuits with wideband common mode suppression
Abstract
As an important component of today's wideband wireless communication，wideband bandpass filter’s design has a very important research significance and practical value. In the design of the wideband filter, the capability of low loss, miniaturization, high suppression, high selectivity and so on is required.A compact wideband differential bandpass filter with wideband common mode suppression using quarter-wavelength coupled lines is proposed in this letter. Third-order wide passband for the differential mode can be easily realized by the half-wavelength ring resonator.A planar wideband differential filter with 3-dB fractional bandwidth of 64.5% is designed and fabricated. Another new compact wideband differential bandpass filter with wideband common mode suppression using half-wavelength ring resonator is also presented. Fifth-order passband for the wideband differential mode with two transmission zeros close to the passband is realized with four open stubs. A planar wideband differential filter (3-dB fractional bandwidth 77.4%) with wideband common mode suppression is designed and fabricated. The theoretical and measured results agree well and show good in-band filtering performances and high selectivity.
Keywords Bandpass filter (BPF), differential/common mode, half-wavelength, open stub,wideband
目 次
1 绪论 1
1.1 课题研究背景 1
1.2 研究现状 1
1.2.1 宽带滤波器的研究现状 1
1.2.2 宽带差分滤波电路研究现状 2
1.3 本文的主要工作和章节安排 5
2 滤波器基本理论 6
2.1 滤波器基本理论 6
2.2 混合模S参数的分析 7
2. 3 小结 10
3 基于短路开路耦合线的宽带差分滤波器 11
3.1 开路/短路耦合线的传输特性 11
3.1.1 耦合线理论 11
3.1.2 开路/短路耦合线节等效电路 12
3.1.3 平行耦合线的转移矩阵与S参数 14
3.2 第一个差分滤波器 16
3.3 小结 21
4 基于半波长加载的宽带平衡滤波电路的设计 22
4.1 1/4波长、半波长、整波长开路枝节线传输线特性 22
4.2 采用半波长加载的高选择性宽带差采用半波长环形谐振器的紧凑型宽带差分带通
滤波器 23
4.3 小结 29
结论 30
致谢 31
参考文献 32
1 绪论