N258 Frequency Band Circularly Polarized Corner Perturbated Microstrip Patch Antenna

For millimeter-wave applications, a corner perturbated right hand circularly polarized patch antenna has been proposed. To obtain two degenerative modes required for circular polarization, the square patch antenna is perturbated at its two diagonal corners. A quarter wave transformer is used to match the impedance. The antenna is designed to operate at 28 GHz, which is the resonance frequency. The proposed antenna has an impedance bandwidth |S11| (<-10 dB)between 27.671 to 29.294 GHz(5.6982%) and axial ratio(< 3dB) bandwidth between 28.303 GHz to 29.146 GHz (2.934%).The gain is larger than 6 dBi, and the radiation efficiency is over 90%. The proposed antenna has a low profile, a high gain, and a high radiation efficiency, making it ideal for millimeter-wave applications.