Dual band phased array antenna

摘要

The antenna (Fig.1 not shown) comprises a plurality of apertures (2). Each aperture comprises a first antenna element (4) for operating in a first frequency band and a plurality of second antenna elements (5) for operating in a second frequency band. The antenna further comprising control means (8) for controlling the phase of the antenna elements (4, 5) within each aperture relative to the phase of antenna elements (4, 5) within each adjacent aperture. Each aperture (2) is fully filled with respect to the first antenna element (4) and partially filled with respect to the second antenna elements (5) and the second antenna elements are randomly arranged within each aperture. The first antenna element (4) is positioned in accordance with the random arrangement of the second antenna elements (5) within that aperture. The spacing between the apertures (2) ensures no grating lobes for the array formed from the first elements (4) and the random spacing of the second elements (5) also reduces grating lobes despite the low filling factor of e.g. 12%.