Linear-polarized three-beam four-element antenna array with reduced sidelobe level

摘要

A recently developed method of sidelobe level reduction in multibeam circularly polarized antenna arrays fed by Butler matrices has been extended on linearly polarized multibeam antennas with broadside beam. It has been shown that in a three-beam four-element antenna array sidelobe level reduction can be achieved with theoretically lossless feeding network by taking advantage of two-port radiating elements at the expense of having two squinted beams featuring orthogonal linear polarizations with respect to the broadside beam. The presented concept has been verified by the design and measurements of the antenna array operating at 3 GHz for which sidelobes as low as -20 dB have been achieved.