System and Methods for Low-Profile Frequency Selective Surface Based Device

Technology #31285

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Schematic illustration of a multi-layer thirdorder low profile FSS topology according to an embodiment of the invention
Nader Behdad, Ph.D.
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Low-profile frequency selective surface based device and methods of making the same

US Patent 7,639,206 B2

UCF scientists have developed such a multi-layered FSS using regular FSSs and a high quality factor FSS. The result is a high profile FSS with thickness in the order of 1/30 of a wavelength. Due to the overall miniaturization of the FSS, it has reduced sensitivity to the angle of incidence of radiation when compared to typical third order FSS.

Technical Details

Apparatus and methods for the design of low profile multi-layer frequency sensitive surfaces for processing electromagnetic waves and providing at least a third-order-response utilizing third order band-pass response to obtain higher-order frequency response.

Frequency Sensitive Surfaces (FSS) are used in a variety of antenna applications. In order to achieve a higher order filter response, typically multiple identical FSSs are cascaded by stacking then. The distance between the FSSs is determined by the desired order of the FSS - the higher the desired order the larger the distance between FSSs on the stack. Consequently, the physical thickness of the multilayer FSS increases linearly as the order of the FSS increases- usually being in the order of half of a wavelength. The thickness of conventional FSSs such as the FSS 100 is known to result in undesirable sensitivity to their response to the angle of incidence of the radiation. The thickness of multi-layered FSSs also limits the applications for which they are suitable. For these reasons, it is more desirable to use FSSs of small dimensions that are less sensitive to incidence angles but can operate as higher-order FSS.


  • Reduces the thickness of FSS with higher-order band-pass responses
  • Uses sub-wavelength periodic structures thus reducing overall panel size
  • Provides low sensitivity of response to angles of incidence of an incident plane wave


  • Filter, reflector, and transmission applications and in applications involving propelled objects or vehicles
  • Development of multi-band or dual-band antennas such as those used in the design of beam formers for large antenna arrays and in the design of space borne deployable antenna arrays
  • Electronic Counter Measures (ECM) and Electronic Counter Counter Measures (ECCM)
  • Aircrafts and military vehicles for the reduction of radar cross sections for stealth applications, or in radar domes (Radomes) used in commercial or military aircrafts, radars and missiles