Wideband Designs of Regular Shape Microstrip Antennas Using Modified Ground Plane

Abstract

Wideband designs of proximity fed regular shape microstrip antennas using bow-tie and H-shape ground plane profiles are proposed in the 1000 MHz frequency range. The modified ground plane alters the quality factor of the patch cavity which enhances the impedance bandwidth. In terms of the results obtained for the bandwidth and gain together, circular and square patches backed by bow-tie shape ground plane, followed by circular patch backed by H-shape ground plane yield optimum results. For substrate thickness of 0.097λ g , against the conventional ground plane, bow-tie shape gives 12% and 24% bandwidth increment for the circular and square patches, respectively, and H-shape ground plane yields bandwidth increment by 17% in the circular patch. All these wideband designs offer a peak gain around 6 dBi with a broadside radiation pattern. Further, a modified ground plane profile helps in optimizing the proximity fed antennas on lower substrate thicknesses. Amongst all the configurations, for ∼ 0.03λ g reduction in the substrate thickness, square microstrip antenna using bow-tie shape ground plane yields 19% increase in the impedance bandwidth against the equivalent thicker substrate design with a peak broadside gain of above 6 dBi. Thus, the proposed modified ground plane antennas yield bandwidth improvement but for a smaller substrate thickness.

Wideband and Compact Regular Shape Microstrip Antennas Employing Rectangular Slots Cut Bow-tie Shape Ground Plane

“…Also, details about the antenna working in terms of patch resonant modes and design methodology are not discussed. Wideband designs discussed in [26][27][28] do not provide a reduction in patch size or the frequency as bow-tie shape does not perturb the current distribution in the patch center where the maximum of modal current is present. Against the reported wideband configurations, proposed work explains a technique to yield wider BW supported with reduction in patch resonant mode frequency (patch area) on an electrically thinner substrate.…”

“…2(e), (f). In the bow-tie shape designs reported in [26][27][28], the reduction in patch fundamental mode frequency is not achieved. As against that in the proposed design, the presence of a rectangular slot before the realization of bow-tie shape of the ground increases perturbation in current vector lengths that reduces the resonance frequency.…”

“…With the reduction in the substrate thickness, a parametric study against the variation in ground plane depth 'd' to achieve wider BW is carried out. Since this study for bow-tie shape of the ground is well elaborated in [26], it is not presented here. With a bow-tie shape of the ground, broadside peak value of the gain decreases, but it provides BW improvement on a thinner substrate.…”

Compact wideband microstrip antennas using C, H, and W‐shape ground plane for GSM band applications

“…Against this, the proposed MSA offers stable gain characteristics across the S 11 BW. In modified ground plane MSAs discussed in Deshmukh et al, 12 Poonam and Deshmukh, 15 and Deshmukh et al, 16 and in none of the reported work, a technique to reduce the antenna size, while providing a wider BW is being discussed. Against the reported wideband MSAs, the present study not just discusses another wideband configuration on thinner substrate but provides a simple technique that reduces the patch resonance frequency (size).…”