新型CRLH传输线带通滤波器设计

Novel design of CRLH transmission line bandpass filter

设计了一种新型双负介质传输线结构,该传输线结构具有负的磁导率和负的介电常数,同传统的混合左右手(composite right/left-handed,CRLH)传输线相比,该结构以更简单的构成、更小的尺寸实现了更好的左手媒质特性。应用该结构设计制作了一个任意可调双频带谐波抑制带通滤波器,测量结果显示:该滤波器第一个通带位于2.45 GHz,具有0.5 dB的插损和56%(1 400 MHz)的3 dB带宽;第二个通带位于5.8 GHz,具有1 dB的插损和27%(1 600 MHz)的3 dB带宽。这种CRLH传输线滤波器在无线通信、导航等多频带微波系统中具有良好的应用价值。

A novel double negative （DNG） transmission line media, which had a negative permeability and a negative permittivity, was presented. Compared with normal composite fight/left-handed （CRLH） transmission line, the novel structure achieves a better left-handed medium properties with a more simple structure, fewer circuit size. Moreover, a compact arbitrary dual band microwave bandpass filter was designed and fabricated with the CRLH transmission line. Experimental results show that the first passband at 2.45 GHz of the filter has less than 0.5 dB of insertion loss and 56% （1 400 MHz） of 3 dB bandwidth; the second passband at 5：8 GHz has less than 1 dB of insertion loss and 27% （1 600 MHz） of 3 dB bandwidth. It demonstrates good performance and potential applications in radio-communication, navigation and other multi-band microwave systems.