Curved Frequency-Selective Surface on Hemispherical Dome for Wave Bandpass Filters

Frequency-selective surfaces (FSSs) are periodically arranged lattice structures on surfaces used as wave filters for electromagnetic radiation. They are applied in practice to radomes and antennas. Here, we theoretically analyzed hemispherical FSSs using the finite-difference time-domain method. The implementation of metal patch and hole array elements was demonstrated for different applications, such as bandpass or bandstop, in the frequency range of 5–25 GHz. Furthermore, the tunability of the operating frequencies for the bandpass characteristics was confirmed by controlling the periodicity and diameter of the elements. We also achieved a high selectivity at the desired frequencies to transmit and reflect electromagnetic radiation by varying the period, diameter, and radius of curvature. These results can advance theoretical modeling methods for curved FSS structures and functional wave filtering performance using hemispherical dome substrates.