IMPROVEMENTS IN AND RELATING TO RADAR

An antenna comprising two or more substantially identical antenna sub-arrays (3A, 3B) each comprising a plurality of separate antenna radiating elements (6A, 6B) connected to a common radio frequency (RF) signal input/output port (4A, 4B). The separate antenna elements are connected to the RF signal input/output port via respective RF signal power dividers (8A, 8B). A variance in values of the power splitting ratio, and/or of the input RF signal reflectivity, and/or of the phase balance of corresponding signal power dividers of the two or more antenna sub-arrays is sufficient to provide a cancellation ratio exceeding 40 dB. Alternatively, the separate antenna elements are connected to the RF signal input/output port via respective transmission paths (7A, 7B) and a variance in values of the transmission path lengths of corresponding signal transmission paths of the two or more antenna sub-arrays is sufficient to provide a cancellation ratio exceeding 40 dB.