Wideband Compact Designs of Circular and Equilateral Triangular Microstrip Antennas Employing Rectangular Slots Cut Ground Plane

Abstract

ABSTRACT Compact and wider bandwidth designs of proximity fed circular and equilateral triangular microstrip antennas backed by rectangular slots cut ground plane are proposed. Slot on the ground plane reduces the fundamental mode frequency on each of the patches that yield wideband characteristics in a lower frequency band. Among the proposed designs, circular patch and its multi‐resonator variations employing slots cut ground plane achieve optimum results. The single circular patch achieves 22.5% reduction in fundamental mode frequency, 47.66% reduction in patch area, 0.027λ g11 reduction in thickness of the substrate supported with 10% increase in reflection coefficient bandwidth. Gap‐coupled circular patch designs achieve 10% reduction in the start frequency of the bandwidth, more than 30% reduction in the total patch area, with more than 15% increase in the bandwidth. For all these improvements, slot cut ground plane antenna exhibits only 1 dBi reduction in the peak broadside gain. Considering all the antenna parameters together, slots cut ground plane present substantial improvement, so as to achieve a compact wideband solution. Design methodology for circular patch employing slot cut ground plane is presented. It is useful in realizing similar configuration as per specific frequency band of wireless application. Measurements in the proposed designs have been carried out that show close agreement against the simulation.