CPW-fed broadband circularly polarized microstrip rectangular slot antenna with circular shaped tuning stub

In this paper a rectangular slot antenna fed by coplanar waveguide (CPW) with circular shaped tuning stub for broadband circular polarization is presented. Two circular metallic arcs shaped grounded perturbation are introduced at diagonally opposite corners of the rectangular slot to obtain circular polarization with wide axial ratio bandwidth. This slot antenna has been designed and optimized on a FR4 substrate with dielectric constant ε_r= 4.3 and substrate thickness h=1.53mm. The simulated results of this antenna show impedance bandwidth 151.64% from frequency range 1.93GHz to 14.06GHz at VSWR ≤ 2 throughout this band and axial ratio band width 32.68% from frequency range 3.7GHz to 5.14GHz. The simulated radiation patterns of this antenna are Omni-directional in H-plane and Bi-directional in E-plane. The effect of variation in radius of metallic arcs on impedance bandwidth and axial ratio bandwidth has also been analyzed using HFSS Simulator. The proposed antenna can be easily integrated with radio-frequency/ Microwave Circuitry with low manufacturing cost.