Low-Cost All-Metal Bandpass Frequency Selective Surface

In this paper, a new type of low-cost free-standing all-metal frequency selective surface (AM-FSS) is studied and presented. The AM-FSS is developed using an extremely thin sheet of metal having a total thickness of λ0/80, where λ0 is the free-space wavelength at the operating frequency. The fundamental element of the AM-FSS is a square ring of area 0.45λ0 × 0.45λ0 and having fork-type stubs extending from four sides towards the center of the ring. The transmission and reflection characteristics of the AM-FSS are predicted using a commercial electromagnetic simulator. Higher-order bandpass FSSs are realized using two and three layers of the proposed AM-FSSs. The independent polarization characteristic of the AM-FSS is demonstrated by predicting the performance of the three-layered AM-FSS for two orthogonal TE and TM polarizations. The proposed AM-FSS does not use any commercial laminates, making it extremely attractive for low-cost and high-power microwave applications