Design of a circular polarized horn filtenna using complementary electrically small resonators

We present a circular polarized (CP) filtering antenna (filtenna) consisting of a regular conical horn and a novel polarization transformer. The proposed linear-to-circular polarization transformer is obtained by using complementary electrically small resonators etched on a metallic sheet. This structure behaves both as a polarization transformer and a filter allowing to reduce the impedance bandwidth of the conical horn to avoid additional noise in satellite receiving systems. The proposed antenna, operating at X-band, exhibits a CP realized gain of 17.5 dBic.