准椭圆函数滤波器的边带优化设计  

Band-edge optimization design of the quasi-elliptic filter

作　　者：朱永忠[1,2] 谢拥军[1] 谢文宣[3] 李亚峰[1] 

机构地区：[1]西安电子科技大学天线与微波技术重点实验室,陕西西安710071 [2]长安大学信息工程学院,陕西西安710064 [3]国家无线电频谱管理研究所,陕西西安710061

出　　处：《西安电子科技大学学报》2009年第3期448-451,467,共5页Journal of Xidian University

基　　金：教育部新世纪优秀人才支持计划资助(NCET-04-0950)

摘　　要：提出了标准椭圆函数的边带优化方法,在此基础上使标准椭圆函数与修正后的准椭圆函数在边带上的衰减相等,得到准椭圆函数的等波纹系数.这种修正后的准椭圆函数不仅能保持设计带宽不变,亦能提高滤波器的边带衰减.最后,据此设计了一种新型螺旋形SIR四腔准椭圆函数滤波器,实测表明这种结构的尺寸可减小15%,过渡带减少20 MHz,而且可以将二次与三次谐波抑制在30 dB以下.A new technique is presented for maximizing the band-edge selectivity of elliptic filters, and then the equal ripple parameter of the quasi-elliptic function can be calculated when the band-edge selectivities of the elliptic function and quasi-elliptic function are the same. The quasi-elliptic function based on the method not only keeps the bandwidth invariable, but effectively narrows the transition band. Finally, a novel quasi-elliptic microstrip filter composed of four spiral stepped-impedance resonators （SIR） is designed. Measured results show that the filter acquires 15~ size reduction and 20 MHz transition band reduction, but can also effectively inhibit the second and third harmonics.

关 键 词：准椭圆函数 交叉耦合 传输零点 边带特性 

分 类 号：TN713.5[电子电信—电路与系统]