CPW-fed dual-band dual-sense circularly polarized antenna for WiMAX application

Abstract

—This paper presents a CPW-fed dual-band dual-sense circularly polarized square slot antenna (CPSSA). The antenna consists of a rectangular radiator with two unequal rectangular strips, connected by a CPW feed line. An inverted L-shaped grounded stub is placed in the right side of the slotted ground plane with the orthogonal direction of the feed line to create CP modes. The proposed antenna obtained two CP bandwidths of 3.30–3.78 GHz and 5.4–5.86 GHz with axial ratio (AR) value less than 3 dB, and both the CP bands are overlapped by impedance bandwidth (IBW) of the antenna, ranging from 2.72 to 7.34 GHz. Total size of the proposed antenna is 50×50×1.58 mm3. The antenna is fabricated on an FR4-epoxy substrate and measured. Simulation results are verified by measurement for the given antenna. The designed antenna is well used for WiMAX (3.5 GHz and 5.5 GHz) band with CP characteristics. Design procedures of the antenna are discussed in details for further understanding of the antenna design. Parametric study has been done for describing the mechanism of the dual-band CP with the analysis of electric current distribution of the antenna. Meanwhile, wide axial ratio bandwidth has been obtained in both the bands using this structure compared to other published structures.