Substrate integrated frequency selective surface in microwave and terahertz bands

Abstract

Frequency selective surface (FSS) based on substrate integrated waveguide (SIW) technology is a passband spatial filter with periodic arrays of slots, which has wide applications, such as the sub-reflecting surface of the reflector antenna, and the antenna radome. Compared with the conventional FSS, the SIW FSS is a better candidate with high rectangular coefficient, good incident angle stability, low loss and easy fabrication using the PCB process. The existing SIW FSS unit has a relatively large area which leads to poor grating lobe suppression. In this presentation, an X-band FSS based on a quarter-mode SIW (QMSIW) cavity will be presented, which pushes the grating lobe up to high frequency band. Based on the QMSIW cavity, a two-band FSS and a four-band FSS are investigated subsequently. After that, the design of a THz SIW FSS is introduced. A FSS using the hexagon SIW cavity is designed in THz band. The FSS with the hexagon element has a wide band and good incident angle stability. Besides, it has a good out-of-band suppression and polarization stability.