Polarization‐dependent electromagnetic band gap (PDEBG) structures: Designs and applications

Abstract
EBG structures exhibit an in‐phase reflection coefficient, which makes them desirable for low‐profile antenna designs. However, a conventional EBG structure has an identical reflection phase for a normally incident plane wave in spite of its polarization state. This paper presents novel polarization‐dependent EBG (PDEBG) structures whose reflection phases are different, depending upon the polarization state of the incident plane wave. This polarization‐dependent reflection‐phase feature is realized by changing the unit geometries, for example, by using a rectangular patch to replace the square patch, by cutting slots into the patch, or by offsetting the vias. By properly tailoring the phase difference between different polarizations, a useful EBG reflector is introduced, which can control the polarization state of the reflected wave. One attractive application of this reflector is that the reflected wave of a circularly polarized incident plane wave can maintain its polarization sense. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 439–444, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20164