Double bow-tie FSS for X-band and K$_u$-band operations with its parametric analyses

This paper demonstrates double bow-tie frequency selective surface (FSS) geometry for X-band applications with a bandwidth value of 1.82 GHz and K$_u$-band applications with a bandwidth value of 3.44 GHz. Throughout this study, parametric analyses of the proposed structure are also performed. Alterations in the reflection and transmission characteristics of this specially designed structure by virtue of defined variables are analyzed. Those variables are determined by considering the geometric and material properties of the proposed structure. To analyze the reflection and transmission coefficients, two different simulators, namely the High Frequency Structure Simulator (ANSYS HFSS), which is based on the finite element method (FEM), and the Computer Simulation Technology Studio Suite (CST Studio Suite), which is based on the finite integration method (FIM), are used. The structure is validated via those two solvers. Good agreement is obtained by both solvers, and the results are compared in terms of frequency, return loss, insertion loss, and fractional bandwidth.