Rectangular Ring Antenna Excited by Circular Disc Monopole for WiMAX System

This research presents a rectangular ring antenna excited by a circular discmonopole (CDM) mounted in front of a square reflector. The proposed antenna is designed to cover a frequency range of 2.300-5.825 GHz and thereby is suitable for WiMAX applications. Multiple parametric studies were carried out using the CST Microwave Studio simulation program. A prototype antenna was fabricated and experimented. The measurements were taken and compared with the simulation results, which indicates good agreement between both results. The prototype antenna produces an impedance bandwidth (vertical bar S-11 vertical bar < 10 dB) that covers the WiMAX frequency range and a constant unidirectional radiation pattern (theta = 0 degrees and empty set = 90 degrees). The minimum and maximum gains are 3.7 and 8.7 dBi, respectively. The proposed antenna is of compact size and has good unidirectional radiation performance. Thus, it is very suitable for a multitude of WiMAX applications.