Influence of element shape's tiny change on electrical performance of frequency selective surface

In order to realize the role played by aperture shape in the electrical performance of frequency selective surface (FSS), the influence of the aperture shape's tiny change on band-pass FSS is studied according to the laws of the aperture tangent electric field distribution. The results show that the shape change in the zero points of aperture tangent electric field of some special elements influence the electrical performance of FSS tempestuously. This phenomenon is hard to explain by the laws of aperture tangent electric field distribution but has a close relationship to the mode of the currents distribution on the unit cell. On the base of the research on the induced currents distribution, the relationship between resonance and induced currents distribution is presented. This relationship can be described as that every resonance is corresponding to a reverse of induced current on some area of the conduct layer which is defined as the current reverse mode in this study. The electrical performances will be the same as long as the electric field distribution or the current reverse modes is similar. This conclusion can be applied to solve complicated elements FSS and design FSS structures with different polar properties.