Finite‐ground‐plane effects on the ultra‐wideband planar monopole antenna

Impedance and radiation characteristics of an ultra-wideband (UWB) planar monopole antenna with a finite circular ground plane are experimentally studied. The significant effects of the ground-plane size on the lower-edge frequency of the antenna's impedance bandwidth are observed, and there exists an optimal diameter of the circular ground plane for achieving a maximum impedance bandwidth. Large ground-plane effects on the radiation pattern and antenna gain are also seen, especially for the lower frequencies in the antenna's UWB impedance bandwidth. Details of the experimental results are presented and discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 535–537, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20526