Iterative Synthesis of Equi-Ripple Dual-band Filtering Functions With One Additional Transmission Zero

Author(s):  
Ping Zhao ◽  
Ke Wu
2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Wenxing Li ◽  
Yuanyuan Li

A novel, highly selective, low profile dual-band, and bandpass miniaturized-element frequency selective surface is proposed to realize stable angular responses and a controllable transmission zero. This FSS is a three-layer structure consisting of three metal layers that are separated from each other by two dielectric substrates. The equivalent circuit model of the FSS and its operating principle are presented and analyzed based on the microwave filter theory. The prototype of this FSS is simulated, fabricated, and measured, and its theoretical analysis, simulation, and measurement results show a good agreement. This FSS has achieved an excellent angular stability and wide out-of-band rejection performance in the scope of incidence angle of 80 degrees. Compared with the other multilayered FSSs and 3D FSSs proposed in previous works, it possesses a lower profile as well as a smaller size. A transmission zero is produced by etching slots on the edges of the middle metal layer to achieve superior frequency selectivity. By properly choosing the size and direction of the slots, the transmission zero and the polarization selectivity are able to be changed, respectively.


2017 ◽  
Vol 9 (7) ◽  
pp. 1447-1452
Author(s):  
Di Lu ◽  
Teng-Fei Yan ◽  
Xiao-Hong Tang

In this letter, a passive high-selectivity dual-band filter with two controllable transmission zero (TZ) pairs is proposed, while synthesis method and control mechanism of the two TZ pairs are investigated. Specifically, by employing the magnetic/electric mixed coupling (MEMC), source–load coupling (S–L coupling) and stepped-impedance resonators, a dual-band bandpass filter with two pairs of controllable TZs is constructed. Two controllable TZ pairs can be independently adjusted by re-modifying the associated coupling structures. To validate the synthesizability and controllability of the TZ pairs, mathematical synthesis, and EM simulations are carried out. Two demonstrative filters with identical passband performance and different central TZ distributions for GSM (0.9/1.8 GHz) are designed and measured. The analysis and experimental results show that the synthesis-controllable TZ pair (fz2, fz3) introduced by MEMC can be synthesized and controlled using inline mixed coupling synthesis, and the optimization-controllable TZ pair (fz1, fz4) because of S–L coupling is controlled by S–L coupling strength optimization procedure.


2018 ◽  
Vol 17 (12) ◽  
pp. 2469-2473 ◽  
Author(s):  
Kirti Dhwaj ◽  
Li Jun Jiang ◽  
Tatsuo Itoh
Keyword(s):  

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