Integrated filtering in a planar array of connected dipoles including a common-mode rejection module

A smart design strategy for a planar X-band phased-array antenna of connected dipoles with inherent filtering properties is described. As shown in previous works, the use of a common-mode rejection module is necessary in order to suppress undesired resonances excited when scanning on the E-plane. In the present solution, part of the filtering function is performed by the dipole, acting as first resonator, while the other part is integrated in the common-mode rejection module consisting in a planar hybrid-ring. As shown in the simulation results, scanning capabilities up to 45° in the H-plane and up to 30° for the E-plane are achievable with a fractional bandwidth of 21%.