A Miniaturized Conical Bandpass Frequency Selective Surface With Frequency Response Stability

In this letter, a miniaturized conical bandpass frequency selective surface (FSS) with excellent transmission performance stability for radome applications is proposed. The angular stability of the designed FSS structure in the planar state can reach 80°. Furthermore, when the FSS structure is conformal on a conical surface with a half-angle <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">α</i> of 30°, the resonant frequency shifts are less than 1.21% under both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> polarization. Finally, the FSS structure is fabricated and measured in the planar and conical states. The experimental results indicate that the angular stability of the conical FSS with a half-angle <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">α</i> of 41.9° can be up to 75°. A good agreement between the simulated and measured results verifies the effectiveness of the designed FSS.