High Selectivity FSS With Three Independently Controllable Transmission Poles Using Matrix Synthesis

In this letter, a high selectivity frequency selective surface (FSS) with three independently controllable transmission poles (TPs) is proposed by using matrix synthesis. The response with three TPs and four transmission zeros is obtained by employing a triplet topology. The matrix synthesis method provides a theoretical analysis for coupling elements regarding to three independently controllable TPs. Also, the synthesized matrix gives a good prediction of flexile responses with allocated center frequency and bandwidth. To be verified, a finite FSS prototype with 15 × 15 unit cells is fabricated and tested. The measured results are mostly consistent with simulated and synthesized ones, manifesting merits of high selectivity, flexible design, and low profile.