High gain and wideband patch antenna with wide 3‐dB axial ratio bandwidth operating at TM01 and TM11 modes

Abstract

Abstract A wideband and high gain circularly polarised patch antenna has been introduced. The proposed antenna combines an aperture coupled feeding with a T‐slot, four metallic vias and a patch with a diagonal slot to present high gain and wide 3‐dB axial ratio bandwidth (BW) characteristics. In this study, a rectangular patch (0.6 λ0 × 0.5 λ0 at f = 7.5 GHz) with a diagonal slot has been symmetrically located above the T‐slot at the height of 0.07 λ0. A WR90 waveguide with the length of 50 mm and a T‐slot in its extended outer wall has been used as a primary antenna that feeds the patch element. Four metallic vias with shunt inductive effects have been used to virtually enlarge radiating patch dimension, so they present a significant improvement in antenna gain, BW and axial ratio. The proposed antenna shows the BW of 30% with tgain of up to 12 dBi and an axial ratio BW of 21%. Due to its wideband, high gain, and wide 3‐dB axial ratio BW, this antenna is a good candidate for some applications, such as small satellites, and for the global positioning system the high gain, precision and flexibility of the system are crucial.