A High-Gain Filtering Antenna Based on Folded Reflectarray Antenna and Polarization-Sensitive Frequency Selective Surface

In this letter, the concept of high-gain multifunctional antenna based on folded reflectarray antenna (FRA) and polarization-sensitive frequency selective surface (FSS) is proposed. Antenna with multiple functions can be realized by using a polarization-sensitive FSS as the subreflector of FRA instead of the traditional polarizing grid. To validate this concept, a high-gain filtering antenna designed at Ka -band is presented as a design example. Good filtering performance of the antenna has been achieved due to the frequency selective characteristics of FSS. Besides, the relationship between the focal-length-to-diameter ( F/D ) ratio of FRA and the size of FSS element has also been discussed.