Gain enhancement of a microstrip patch antenna using a circularly periodic EBG structure and air layer

This paper describes the gain improvement of a circular microstrip patch antenna achieved using an electromagnetic bandgap (EBG) structure and an air layer. The microstrip patch antenna was fed by a coaxial probe and integrated in an EBG substrate that included an air layer. The gain of this antenna was 6.5 dB greater than that of a conventional circular patch antenna. The actual measured radiation patterns and gains of the proposed antenna agreed closely with simulated results.