Experimental investigation of a microstrip planar feeding network for a switched-beam antenna array

The main causes of degradation of quality of communication and capacity of communication systems are multipath fading and interference. Conventional antennas are not suitable in hostile environments and more sophisticated antennas have to be developed. We propose a new switched-beam antenna array (SBA) for improving the quality of transmission and enhancing the cellular capacity, range and coverage. This SBA is based on a microstrip planar 8×8-Butler matrix, which allows us to produce 8 or 7 orthogonal narrow beams. According to the received signal power criterion, one of these beams can be selected and steered in the direction of a desired user. In this paper, the prototype implementation of the Butler matrix is presented. To examine the performance of the feeding network, experimental measurements were carried out on the Butler matrix. To validate our approach, a comparison between measurements and simulations is given.