Thinner Substrate Designs of Modified Ground Plane E–shape Microstrip Antennas for Wideband Response

ABSTRACT Wideband designs of a coaxially fed pair of slot cut square, circular, and equilateral triangular microstrip antennas employing the H-shaped or Bow-tie shaped ground plane profile are presented on an electrically thinner substrate (ht ~ 0.04λg). The modified ground plane yields an optimum impedance matching for the response inside VSWR = 2 circle that gives a wider bandwidth. Among all the slot cut regular shaped microstrip antennas, an optimum response in terms of the bandwidth and gain against the substrate thickness reduction is achieved in E-shaped square microstrip antennas backed by the Bow-tie shaped ground plane. Against the thicker substrate design (ht ~ 0.07λg), it yields bandwidth increment by > 10% and reduction in the substrate thickness by 0.03λg, with a peak broadside gain of 6.2 dBi. An experimental validation is carried out in all the proposed configurations that show close matching with the simulations.