Multi-Beam Patch Antenna Design

ABSTRACT: This thesis describes the design procedure of a circular microstrip antenna array to be used for wireless communications. The proposed antenna utilizes a novel feed network that enables the user to change the propagation direction by choosing one or more of the four input ports. Equilateral triangular patches are used as array elements to utilize the space efficiently around the circular feed network. Both the feed network and the radiating elements are placed on a 1.57 mm thick FR-4 substrate, which is suspended 5 mm above the ground plane. The antenna array is designed to operate at a center frequency of 2.45 GHz. Results show that single beams at eight different directions can be obtained by exciting certain combinations of input ports. Other combinations allow the array to radiate simultaneously in two directions. The dual-beam operation is possible in two different configurations. The steering angle is around 10o off the z-axis and the beamwidth is around 20o for all of the main beams. Gain values of up to 8.3 dB were obtained. Keywords: Circular antenna array, Triangular patch, Multi directional, Multi beam, Circular power divider. ……………………………………………………………………………………………………………………………………………………………………………………………………………………