Circularly polarized proximity-coupled microstrip antennas

A novel design for the production of circularly polarized radiation (CP) in proximity‐fed microstrip antennas is presented. To achieve this circular‐polarization design, the two orthogonal modes of the microstrip antenna are excited in series through the proximity coupling of an L‐shaped open microstrip line. The experimental results show that the 3‐dB axial‐ratio CP bandwidth of the proposed design is increased by more than 30%, as compared to a conventional CP microstrip antenna of the same size. The details of the simulated and experimental results for the proposed design are presented and discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 429–430, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21006