Broadband and high gain circularly polarized mushroom‐loaded nonuniform patch array antenna with aperture CPW feed

The circularly polarized antenna with high gain and broad bandwidth in single layer substrate is realized with mushroom‐loaded nonuniform square patches and aperture CPW feed for 5 GHz Wi‐Fi applications. An array of nonuniform square patches are excited by using a uniform aperture CPW feed. Moreover, the mushrooms are connected between the patches and the ground plane to reduce the spurious radiations on the patch. Mushrooms are moved in the diagonal direction of patches to generate circular polarization. The dimensions of the middle patches are increased and the mushrooms of the middle patches are moved further in the diagonal direction to enhance the impedance bandwidth (IBW) and 3 dB axial ratio bandwidth (ARBW). An array of mushroom‐loaded nonuniform square patches with aperture CPW feed has achieved an IBW of 54.2% (4.76–8.3 GHz), an ARBW of 14.3% (5.49–6.29 GHz) and the peak gain of 9.5–9.9 dBi over 5 GHz Wi‐Fi band.