A wideband tightly coupled phased array with reduced scattering characteristics

A low profile ultra-wideband tightly coupled phased array with wide-scan and reduced electromagnetic scattering characteristics is presented. The array is based on the implementation of the continuous current sheet concept, and the tightly coupled dipoles are employed as the array units. The low scattering characteristics of the array is accomplished by the implementation of a novel polarization conversion metamaterial (PCM) and the principle of passive cancellation. Simulated results show that the array can achieve 4:1 bandwidth while scanning up to ±60° in the E-plane for VSWR<2.5 and ±50°in the H-plane for VSWR<3. As a test case, the array without PCM is simulated to demonstrate the proposed strategy for scattering characteristics reduction. The simulated results show that the designed PCM makes the array out-band scattering characteristics dramatically reduced from 12fL (fL denotes the lowest operating frequency) to 36fL. And the radiation characteristics of the array are well preserved.