A simple switched beamforming network for four‐beam Butler matrix

A simple switched beamforming network with one 90° hybrid, two switches, and delay lines is designed. By controlling the switches, the antenna can produce four beams with the phase differences between adjacent radiating elements being ±135° and ±45°. The proposed feed network is simple, provides a tapered amplitude distribution, and has the same phase characteristics as the four-beam Butler matrix feed network. The measured S11 of the proposed antenna is less than −10 dB at the operating frequency of 11.2 GHz. When switch 1 is in the “on” position and switch 2 is in the “off” position, or when both switches are in the “on” position, the measured radiation pattern shows that the scan angles are −12° and +35°. The proposed array antenna has the advantage of low cost, small volume, and easy fabrication. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1413–1416, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24352