Circularly Polarized Annular Ring Microstrip Antenna for High Gain Application

Design, simulation and measurement of high gain annular ring microstrip antenna with L-shaped strip for circular polarization is presented. The simulated and experimental results are obtained using Ansoft's commercially available High Frequency Structure Simulator (HFSS, Brookfield WI) software and the Agilen (Santa Clara, CA) vector network analyzer (N5230A.PNA-L), respectively. Parametric study of input characteristics of the proposed antenna is carried out using modal expansion cavity model and circuit theory concept. Theoretical, simulated, and measured results show good accord between each other. For the TM12 mode, measured results illustrated an impedance bandwidth and axial ratio bandwidth of 28.20 and 10.4%, respectively. With high gain, low profile, good radiation pattern, and simple structure, it can find potential industrial application in X-band to communicate between peripherals with each other.