A compact switched-beam array antenna for mobile satellite communications

This paper presents the design and development of a compact switched-beam array antenna for operation with the Australian mobile satellite communications system. Mobilesat(TM). The antenna is formed by eight aperture-coupled microstrip patch elements that are positioned on the side of a truncated comb Two elements, facing the satellite, are activated using an eight-way two-ports-on radial switch. The output ports of the radial switch incorporate 1-bit phase shifters A total of 24 beams are produced using this beam-forming system. lit order to reduce the manufacturing cost, inexpensive substrates and low-cost UHF p-i-n diodes are employed Further reduction in cast is achieved by eliminating coaxial connectors between the beam-forming network and the antenna elements. Experimental results are presented for the individual antenna elements, the beam-forming network, and the entire switched-beam array. (C) 1999 John Wiley & Sons, Inc.