US Patent 7733285 Integrated, closely spaced, high isolation, printed dipoles

An antenna configuration includes two closely spaced antennas each positioned so as to be orthogonally polarized with respect to the other. The antenna configuration increases antenna isolation and reduces electromagnetic coupling between donor side antenna and repeat side antenna. The antennas include printed dipoles connected to respective transceivers through respective baluns to balance the non-symmetrical portions of the antenna feed paths to reduce unwanted radiation therein. Printed features such as chokes and non-symmetrical and non-parallel structures are preferably included in the ground plane of a multi-layer circuit board to reduce or eliminate circulating ground currents.