Electronic beam steering in wire and patch antenna systems using switched parasitic elements

We explore the application of two alternative methods of electronically controlling the radiation pattern from an antenna array which has a single feed line. Type (a) involves switching one of the parasitic elements to become active. Type (b) requires switching the parasitic elements located in the vicinity of the active element between short circuit (i.e. continuous conduction in the element) and open circuit at a point where the induced current is minimised. Both techniques offer a reduced radiation loss in the feed network and relatively simple control circuitry and tracking software.