Performance Comparison between Different Structures of FSS in Terms of Angular Stability

Due to the importance of angular stability in affecting Frequency Selective Surface (FSS) response such reflection/transmission, bandwidth and resonant frequency, this paper presents the comparison between the performance of top listed FSS structures based on basic shapes of cross, circular, and square loop. The design, simulation, and optimization process have been carried out using CST Microwave Studios software at resonance frequency of 2.5THz. Each selected design obtains transmission coefficients (S
₂₁
) of 0.753dB, 0.824dB and 0.893dB for cross, circular, and square shape, respectively. All the designs have been analyzed in terms of their performance with the angle of incidence ranges from 0° to 60°. From the analysis, it is shown that the square loop structure offers more stability in every analysis compared to other structures. Through simulation, surface current intensity, shown all FSS structures have the capability of enhancing the detection and sensing abilities. Moreover, all structures involved shown more than 90% increase in the surface current intensity as compared to FSS layer (vacuum) which can be applied towards future sensing and detection application.