AbstractThe frequency‐selective property of an array of rectangular microstrip elements that are resonant at a single frequency and show polarization independency is investigated both theoretically and experimentally. Investigation of the conventional frequency‐selective surface (FSS) of an array of rectangular microstrip patches resonant at a single frequency shows that if the source polarization is changed, the response of the FSS changes very distinctly. But in our modified structure, the frequency response of the FSS remains independent of the source polarization. The measured data indicate a prominent band separation between the transmission and reflection bands of the FSS in the transmission coefficient versus frequency plot. The simulation of the above polarization‐independent FSS has also been carried out in the transmission coefficient versus frequency plot by using a new algorithm of the finite‐difference time‐domain (FDTD) method. It is observed that the simulated result comes very close to the experimental result. This FSS may find applications in satellite communication, especially in the field of radio astronomy where polarization from the source is completely unpredictable or need not be known. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 249–251, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20601