• microstrip antenna;
  • circular polarization;
  • metamaterial;
  • wideband


A new design of a wideband circularly polarized microstrip patch antenna with dual capacitively coupled feeds is presented in this article. Axial ratio bandwidth enhancement is achieved for microstrip patch antenna using a broadband quadrature power splitter (QPS). The microstrip and metamaterial transmission lines are connected to two output ports of a Wilkinson power divider as the QPS to achieve broadband quadrature phase difference. The antenna has been investigated numerically and experimentally. Measured results show that the antenna has an impedance bandwidth of 72.6% and a 3-dB axial ratio bandwidth of 46.9%. The 3-dB gain bandwidth is about 46.3%, with the peak gain level at 7.0 dBi. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1790–1793, 2009; Published online in Wiley InterScience ( DOI 10.1002/mop.24452