开路支节加载的双模滤波器设计  

Two-mode bandpass filter using open stub loaded resonator

作　　者：雷涛[1] 向天宇[2] 陆安江[1] 彭嫚[1,2] 张正平[1] 

机构地区：[1]贵州大学电子信息学院,贵阳550000 [2]贵州师范大学机械与电气工程学院,贵阳550000

出　　处：《清华大学学报（自然科学版）》2014年第1期84-87,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(60666001);贵阳市农业攻关项目(黔科合NY字[2011]3107)

摘　　要：方形环谐振器具有结构紧凑、高品质因数、低辐射损耗等优点,被广泛应用于滤波器、混频器、振荡器、天线设计中。该文采用在方形环谐振器中心加载开路支节的微扰方式,能够在保持奇模频率不变的基础上,通过调节开路支节的尺寸来调节偶模频率,带宽调节更加方便。采用阶梯阻抗微带线结构实现输入/输出与双模谐振器之间的强耦合,增大了带通滤波器的带宽。该滤波器在中心频率4.97GHz处,通带内最小插损为1.33dB,3dB带宽为9.38%,并且具有准椭圆函数响应,改善了带外抑制特性。Having the advantages of compact sizes, high Qs and low radiation losses, square ring resonators have been widely used to design filters, mixers, oscillators, and antennas. A stub-loaded ring resonator was developed to design dual-mode filters. The developed dual-mode resonator was found to have the advantage that the even-mode resonant frequencies can be flexibly controlled whereas the odd-mode resonant frequencies are fixed. Stepped impedance line is adopted to achieve strong coupling between the input/output （I/O） and the resonator, increasing the bandwidth of the filter. The center frequency of the new filter is 4.97GHz, with the minimum insertion of 1.33dB in passband and the 3dB fractional bandwidth of 9.38 %. The results also show that the filter possesses a quasi-elliptic response which improves the stopband rejection.

关 键 词：双模滤波器 方形环谐振器 开路支节 阶梯阻抗线 

分 类 号：TN713.5[电子电信—电路与系统]