EBG based Circularly Polarised Microstrip Antenna for RF applications

Circularly polarized antenna receives much attention in the Radio Frequency (RF) applications such as Global positioning system (GPS) and Mobile applications. In this paper, a monopole capacitive feed square ring circularly polarized microstrip patch antenna (MSA) is proposed. The geometry incorporates L-shaped strips, lightening-shaped strips and capacitive feed strip which is fed by a coaxial probe. The electromagnetic band gap (EBG) structure is incorporated in the design to reduce the surface waves, increasing the gain and axial ratio (AR) bandwidth (BW). Monopole type of ground plane is introduced here. The proposed structure is designed, simulated and fabricated to cover the frequency of 2.3GHz-2.7GHz. The parameters such as return loss (S11), voltage standing wave ratio (VSWR), impedance, AR and radiation pattern are used for analyzing the performance of the antenna. Simulated result is presented, covering the desired frequency bands.