【摘要】 耦合谐振电路在微波滤波器的设计,尤其是在窄带滤波器的过程中起着非常重要的作用。本文采用基于耦合系数和外部品质因数的耦合谐振电路滤波器的方法设计了X波段的开环交叉耦合微带带通滤波器。由于引入非相邻谐振器之间的交叉耦合,在滤波器的输入端口和输出端口之间有多个通路,这种多径结构能在有限频率处产生多个传输零点,而且通过调整传输零点的位置,可以调整滤波器选择性和带内群时延性能。设计的滤波器在介电常数为2.2、厚度为0.254mm的RO5880介质板上加工,测试结果显示,该滤波器具有结构简单紧凑、损耗低、选择性高、带外抑制极佳的特点,具有较好的工程应用价值。更多还原

【Abstract】 Coupled-resonator circuits are of importance for the design of microwave filters,in particular,the narrow band bandpass filters. In this paper,the design method for microstripbandpass filters in terms of coupling coefficients and external quality factors is adopted to design a X band microstrip open-loop cross-coupled bandpass filter. Because of the crosscoupling,a transmission zero is generated at each side of the passband which improves the selectivity and group delay of the filter. The cross-coupled filter is designed and fabricated with RO5880 substrate,with arelative dielectric constant of 2. 2 and a thickness of0. 254mm. Simulation and measured results show that the filter has the characteristic of compact size,low insertion loss,high selectivity and perfect out-of-band rejection.更多还原