Flat-plate steerable antennas for satellite communications and broadcast reception

Flat-plate steerable antennas have a number of potential uses; for example, X-band satellite communications to mobile terminals and K-band DBS television reception. A flat-plate array antenna design which could be used for these applications is described. The antenna consists of a printed element face, a polarisation converter, line distribution networks and a Rotman lens. The main beam of the antenna may be slewed in one plane. The second dimension of steering is achieved by rotating the array within its own plane. Two approaches to producing the slewed main beam are given; one uses a multiport lens and the other uses a lens with a single moveable beam port.