摘要宽带带通滤波器作为当今宽带无线通信中的重要组件，它的设计有着非常重要的研究意义与实用价值。在宽带滤波器的设计中，对低损耗、小型化、高抑制性、高选择性等的性能都有一定要求。本文提出了一种具有宽带共模抑制、采用四分之一波长耦合线的紧凑型宽带差分带通滤波器。差模的三阶宽通带可以利用半波长环形谐振器实现。设计和加工了一个平面宽带差分滤波器（3-dB相对带宽为64.5%)。本文还提出了一个新的具有宽带共模抑制、采用半波长环形谐振器的紧凑型宽带差分带通滤波器。两个传输零点接近通带的两端，五阶通带宽带差分结构利用四个开路短截线得以实现。设计和加工了一个具有宽带共模抑制的平面宽带差分滤波器（3-dB相对带宽为77.4%）。理论与实测结果吻合较好，并且展示了良好的带内滤波器性能和高选择性。33699
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 具有宽频段共模抑制的四端口平衡滤波电路:http://www.751com.cn/tongxin/lunwen_30939.html