High-gain compact circularly polarised microstrip antenna

Abstract

Design of a high gain, small microstrip antenna with circular polarisation (CP) radiation is demonstrated. The small size of the microstrip antenna results from both the high-permittivity superstrate loading and the slits cut in the patch. In addition, the antenna gain is enhanced by setting the superstrate thickness at about one-quarter of the wavelength in the superstrate layer. A typical design with a 30% decrease in antenna size and a 5.2 dB increase in antenna gain, as compared to the conventional CP design, is presented and analysed.