Broadband dual polarised planar aperture arrays for wide field of view applications

The Square Kilometre Array development demands a radio telescope with a high sensitivity, dual polarization and wide field of view over a broad bandwidth to meet the scientific goals. This paper describes a recently developed compact planar aperture array named Octagonal Ring Antenna (ORA). The ORA represents a novel and potentially breakthrough technology using a planar, easily fabricated, structure. It is expressly designed to be a low cost, low loss, wideband array. Based on initial large scale finite array studies prototypes with different geometries have been fabricated and measured. The characteristics and advantages of ORA over other conventional array antenna structures are discussed. The robustness of ORA is investigated in the applications where low cross polarisation and wide range of scan angle are required.