基于新型谐振器的超宽带带通滤波器

A Novel UWB Bandpass Filter Based on Compact Resonator

采用两个新型四阶阶梯阻抗谐振器设计出一种新型超宽带带通滤波器,四个1/4波长的耦合线被平行放置于输入输出端,起到增加耦合强度的作用,三个谐振频率被调整在超宽带带宽(3.1 GHz～10.6 GHz)内。通过优化后,该滤波器在通带内具有五个传输极点,频带宽度在3.6 GHz～10.5 GHz,通带内回波损耗优于15 dB,最小插入损耗为0.6 dB,满足超宽带的传输要求。仿真结果显示,文中设计的滤波器具有小型化、低插入损耗和较好的带外特性等优点。

A compact ultra-wideband（UWB） bandpass filter is proposed by using a pair of four-section stepped-impendence resona- tors. Four quarter-wavelength parallel-coupled lines are longitudinally stretched in the input and output sides to enhance the coupling degree, and all the three resonant of this resonator are properly adjusted to be placed within the UWB. After optimization of this fil- ter, a good UWB bandpass behavior with five transmission poles is realized, the passband is 3.6 GHz - 10.5 GHz,the minimum in- sertion loss is 0.6 dB, and the return loss is higher than 15 dB, fundamentally meet the UWB transmission requirements. The simu- lated result shows that the designed filter has advantages of compact size, low insertion loss＇and good stopband performance.