A novel frequency-selective surface generating two-band pseudo-elliptic frequency response

A novel frequency-selective surface (FSS) is introduced in this paper. The structure proposed is a single-sided printed circuit board (PCB) that generates a pseudo-elliptic type response with two closely spaced passbands. Such a multi-band operating regime is realized owing to additional higher modes excited in the meander-like apertures and involved in electromagnetic interaction. Passbands at the response are independently tuned by adjusting the geometrical parameters of the aperture. Numerical and measured data for X-band FSS are presented for different angles of incidence. Due to the high selectivity, a small frequency ratio of 1.27 for central frequencies of passbands of 4.2% and 5.5% bandwidths is achieved for a normal incidence of linearly polarized wave.