An Incident Angle Insensitive Band-Pass Frequency Selective Surface With Flat Top

In this paper, an incident angle insensitive and polarization stable band-pass frequency selective surface (FSS) with flat top is proposed. Each element of the FSS consists of four metallic layers separated from one another by three dielectric layers. The first and the fourth layer are the same hexagonal loop layers, while the middle two layer are hexagonal convoluted slot layers. This FSS exhibits great stability with the maximum insert loss of the pass-band less than 1dB, as the incident angle is ranging from 0 degrees to 60 degrees for both TE and TM polarizations. The frequency selective surface with angle stability and low insertion loss is very useful in radome field.