CPW-Fed Circularly Polarized Dual-Band Dual-Sense Square Slot Monopole Antenna

A circularly polarized dual-band dual-sense coplanar waveguide (CPW)-fed square slot antenna is designed in this paper. The designed antenna consists of two additional patches. A good impedance matching can be achieved by varying the sizes of patches. In this antenna, there are two impedance bandwidth (IBW) ranges of 2.65–5.43 and 5.77–6.19 GHz, and there are two axial ratio bandwidth (ARBW) ranges of 2.88–3.00 and 4.98–5.35 GHz within the IBW. The dual impedance band designed antenna is meant to operate at resonant frequencies of 4.04 and 5.98 GHz. It generates a dual circularly polarized band that operates at 2.94 and 5.2 GHz. They are left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). Low-cost FR4_epoxy is the substrate material used with dielectric constant of εr = 4.4. The antenna is designed using the Ansoft HFSS software. The main parameters, including reflection coefficient, ARBW, gain, radiation pattern, and radiation efficiency, have been measured, simulated, and analyzed. The lower ARBW band of a proposed antenna can be suitable for some S-band wireless communication applications, and a higher ARBW band can be ideal for WLAN applications.