| A switched parasitic array with 360 degrees of coverage is described. This antenna makes efficient use of the entire aperture for each beam position to produce a set of shaped azimuth sector beams. A fed element excites a field of parasitic elements which serves as an artificial dielectric lens. The challenges of optimizing large parasitic arrays are discussed, and a successful method of dealing with these issues is described in detail. Beam scanning is accomplished by switching the feed element and reactive loading on some of the parasitic elements. Prototype test results are provided. This antenna provides a low-cost, compact alternative to mechanically-scanned or phased array systems with comparable gain. |
