Cavity Array Monopole Multiband Microstrip Antennas with Wide Axial Ratio Bandwidth for C band Applications

This paper describes a novel multiband monopole cavity-backed (MCB) microstrip antenna design with a wide axial ratio bandwidth (ARBW). This study explores the challenge of achieving a wide ARBW in MCB antennas for C-band applications. To attain the desired parameters, the proposed MCB antenna prints a circularly polarized monopole radiator onto the substrate. The cavity-array structures, known as resonating elements, strategically positioned vias on both the monopole-radiating patch and the substrate. The proposed MCB, which consists of semi-circular ring slots, improves impedance matching, radiation, and bandwidth (BW). We present two MCB antennas that meet specific frequency ranges and polarization. The first antenna, with a 5 mm patch size, covers the S, C, and X bands, while the second antenna, with a 3 mm patch size, resonates at the X and C bands. Furthermore, the 5 mm and 3 mm MCB antennas have wide ARBWs of 400 MHz (5.00–5.4 GHz) and 610 MHz (4.87–5.48 GHz), respectively. To determine its superiority, we compare the proposed MCB’s performance to that of other antenna designs. We also examine how the proposed MCB functions in two other configurations: one with circular cavities and one without, as well as semi-circular rings of varied radius. We validate the proposed antenna designs by comparing their simulated and measured results. We compare the suggested antenna to other antennas in terms of ARBW, gain, size, efficiency, BW, and applications.