Design of Multilayer Frequency-Selective Surfaces by Equivalent Circuit Method and Basic Building Blocks

Abstract

An equivalent circuit method (ECM) is proposed for the design of multilayer frequency-selective surfaces (FSSs). In contrast to the existing ECMs that were developed mainly for the analysis of the properties of a given FSS, the presented ECM aims at providing the initial design parameters of an FSS from the desired frequency response. In this method, four types of basic FSS structures are used as the building blocks to construct the multilayer FSSs, and their surface impedances in both the normal-and the obliqueincidence situations are studied in detail in order to achieve more accurate equivalent circuit (EC) representation of the entire FSS. For a general FSS design with expected frequency response, the EC parameters and the geometrical sizes of the required basic building blocks can be synthesized from a few typical S-parameter (S 11 /S 12 ) samplings of the response curves via a simple leastsquare curve-fitting process. e effectiveness and accuracy of the method are shown by the designs of a band-pass FSS with steep falling edge and a miniaturized band-pass FSS with out-of-band absorption. e prototype of one design is fabricated, and the measured frequency response agrees well with the numerical results of the ECM and the full-wave simulations.

Semi-Resistive Approach for Tightly Coupled Dipole Array Bandwidth Enhancement

“…The entire circuit was then used to optimize the FSS network. Each FSS was represented using their respective lumped components equivalent [23], [25]. This approach led to quick optimization and an excellent starting point for fullwave simulations.…”

A simple frequency selective surface structure for performance improvement of ultra‐wideband antenna in frequency and time domains

“…In this context, square loop 2 is widely used for designing FSS structure where band‐pass (BP) or band‐stop (BS) filtering capability can be trimmed suitably in order to accommodate the required reflection (S 11 )/transmission (S 21 ) characteristics. Moreover, square loop type structure with some metamorphism also possesses smaller inter‐element spacing than the patch type element for fitting the wide transmission or reflection characteristics within the desired frequency response 26‐28 …”

Design and analysis of ultrathin X‐band frequency selective surface structure for gain enhancement of hybrid antenna

“…Therefore, miniaturized, wideband and low‐profile FSSs are desirable for such applications. Limitations of multilayer structure are already discussed in introduction section where fabrication and alignment of multilayer structures are the big challenge for achieving wide bandwidth 26,27 . For determining FSS bandwidth, inter‐element spacing plays an important role where BP and BS filtering functionality can be tailored by suitably selecting the FSS elements and arranging them in appropriate fashion in order to subjugate the required reflection/transmission characteristics.…”

“…Limitations of multilayer structure are already discussed in introduction section where fabrication and alignment of multilayer structures are the big challenge for achieving wide bandwidth. 26,27 For determining FSS bandwidth, interelement spacing plays an important role where BP and BS filtering functionality can be tailored by suitably selecting the FSS elements and arranging them in appropriate fashion in order to subjugate the required reflection/transmission characteristics. Generally, square loop element (SLE) is preferred over patch type element as SLE possesses smaller inter-element spacing than the patch type element for constructing the wide transmission/reflection characteristics by metamorphism the basic SLE into some other form and structural performance of these types of structures are verified in References 26-28.…”