Ninja array antenna: novel approach for low backscattering phased array antenna

This study presents a novel concept of a low backscattering phased array antenna, a Ninja array antenna. One of the advantages of the Ninja array antenna over the conventional phased array antenna is low backscattering performance over its operating frequency band, which is not available using a conventional phased array antenna with a band-pass radome. The Ninja array antenna is designed in the same manner as the design of reflectarrays, so that the main lobe of its scattering field is directed to a specific direction except for backscattering one. As a result, its backscattering is reduced in comparison with that of the conventional phased array antenna. Although the Ninja array antenna is composed of non-identical array elements such as the reflectarray, it works as a phased array antenna because desired amplitude and phase of excitation can be obtained numerically via an array element pattern. Numerical simulation is performed and the scattering/radiation performance of the Ninja array antenna is demonstrated.