Circularly polarized microstrip patch antenna using artificial magneto-dielectric substrate with grid structure

Abstract

We propose a circularly polarized microstrip patch antenna that use an artificial magneto-dielectric (AMD) substrate. The proposed antenna has a square patch with dual feeding points and uses a Wilkinson power divider in order to achieve a circularly polarized radiation pattern. The AMD substrate is constructed with a two-dimensional array of single split ring resonators. The antenna has an axial ratio of less than 1.7 dB, peak gain of 0.55 dBic, and exhibits a right handed circular polarized radiation pattern at Korean UHF RFID service band. The size of the antenna is 100 mm × 100 mm × 5.2 mm and the radiating patch measures 65 mm × 65 mm (0.199λ0 × 0.199λ0).