Second-order bandpass frequency selective surface for terahertz applications

In this paper, a two-layered frequency selective surface with miniaturized elements is proposed for millimeter wave and terahertz applications. The advantages of this design are a harmonic free transmission response and low sensitivity of its frequency response to the angle of incidence. Performance of the designed structure is verified using full-wave electromagnetic simulations. The results show a second-order filter response with a center frequency of 0.4 THz with the fractional bandwidth of 25% and more than 25 dB out of band rejection.