Angle diversity performances on a line-of-sight microwave path using a dual-beam dish antenna

Frequency-selective fading occurring in short time intervals under multipath propagation conditions is a cause of unavailability and transmission quality reduction of digital radio systems, especially when high level modulation schemes are employed. The authors discuss briefly the theory of angle diversity and present the preliminary results of an experimental program to compare the performance of antenna angle diversity and space diversity on a 4 GHz, 16 QAM, 140 Mb/s radio link in the north of Italy. In the experiment, a single dual-beam antenna was used, which represents an economical and versatile solution