Same-Sense Circularly Polarized Grid-Slotted Patch Antenna With Wide Axial Ratio Bandwidth

In this paper, a same-sense circularly polarized grid-slotted patch antenna with wide axial ratio bandwidth is proposed. The rectangular grid-slotted patch on top and bottom planes are excited through flipped Z-shaped slots pair using a stripline feed to generate same-sense circular polarization with wider axial ratio bandwidth. Characteristic mode analysis is used in the design of the antenna to analyze the desired orthogonal modes. Variations of the resonant frequencies, axial ratio bandwidths and local minimas with the design parameters are discussed. The antenna has a 3 dB axial ratio bandwidth of about 21% from 4.07 GHz to 5.02 GHz, with the realized gain ranging from 2 to 3.5 dBic.