A Curve-Tripole Element of Frequency Selective Surface

This paper presents an excellent compact wideband frequency selective surface element-curve-tripole element. The contour of this element is a curve consisting of arcs, which is small in terms of wavelength. It can be arranged tightly in a triangular grid so that it has smaller inter-element spacing. And it has good design ability because of its more adjustable structural parameters. Curve-tripole element can be designed both for band-pass and band-stop frequency selective surface with different frequencies and different bandwidth. The paper gives a design example of tri-screen frequency selective surface with the curve-tripole element. The simulated results show that, the FSS with curve-tripole element has excellent band filter characteristic with a flat top and sharp fall off; works well both for wide-band and wide-angle with high transmission rate; grating lobes and the second harmonic are suppressed effectively; the performance outside pass-band is greatly improved.