Wide-band planar monopole antennas

TLDR

The circular disc monopole (CDM) antenna has been reported to yield wide‑impedance bandwidth. The study proposes new monopole configurations—elliptical, square, rectangular, and hexagonal—and a simple formula to predict the lower bandwidth edge. The authors design and analyze these configurations, deriving a formula for estimating the lower bandwidth edge for each. Experiments show the elliptical disc monopole with ellipticity 1.1 achieves a bandwidth of 1.21–13+ GHz at VSWR < 2, while a CDM twice the diameter yields comparable results.

Abstract

The circular disc monopole (CDM) antenna has been reported to yield wide-impedance bandwidth. Experiments have been carried out on a CDM that has twice the diameter of the reported disc with similar results. New configurations are proposed such as elliptical (with different ellipticity ratios), square, rectangular, and hexagonal disc monopole antennas. A simple formula is proposed to predict the frequency corresponding to the lower edge of the bandwidth for each of these configurations. The elliptical disc monopole (EDM) with ellipticity ratio of 1.1 yields the maximum bandwidth from 1.21 GHz to more than 13 GHz for voltage standing wave ratio (VSWR)<2.