BASE-STATION TRACKING IN MOBILE COMMUNICATIONS USING A SWITCHED PARASITIC ANTENNA-ARRAY

Base-station tracking in mobile communications benefits from a directi onal antenna and so requires direction finding technology. A novel tec hnique for electronically directing the radiation pattern of an antenn a array employs a directional array with only one active element and t hree parasitic elements operating near resonance. Three different meth ods of direction finding are assessed; a coarse angular location metho d, a precise angular location method assuming one incident beam, and a precise angular location method with multiple incident beams. An arra y with n elements, if used in conjunction with a relatively simple con troller, can be used to resolve n - 1 signals. This technology can be implemented using both wire and patch antenna-array elements and eithe r linear or circular polarization can be used, lending the technology to applications in both terrestrial and satellite communications syste ms.