The implementation of wide angle and UWB retrodirective linear Van Atta array

Abstract

This paper presents the design, fabrication, and experimental validation of a broadband 1×16 Van Atta reflector array based on compact antipodal Vivaldi antennas. The proposed structure achieves wide azimuthal coverage in addition to ultra-wideband operation, ensuring stable retroreflection over ±90°. The unit element is designed for ultra-wideband impedance matching and high polarization purity, while its integration into the array ensures stable retroreflection across the band. Full-wave simulations were performed in Ansys HFSS, and the fabricated prototype was tested in a calibrated anechoic chamber. Monostatic radar cross-section (RCS) measurements showed strong agreement with simulations. The contribution of this work lies in experimentally demonstrating a 1×16 passive Van Atta array with octave-wide impedance bandwidth (8.5–17.5 GHz, with $$|S_{11}| < -10$$ dB for all elements) and wide-angle retroreflection, extending the broadband capability generally achieved in Vivaldi-based designs. Compared with an equal-aperture metallic plate, the array exhibited substantial RCS enhancement across the full angular range, validating its broadband retrodirective behavior. Measurements of the unit element confirmed its polarization purity, with XPDR consistently above 10 dB across the band. Compared with prior studies, the proposed array uniquely combines octave-wide operation, wide angular stability, structural simplicity, and reproducibility, verified by both simulation and experiment. These features highlight its suitability for applications in radar signature management, secure wireless links, asset tracking, and defense applications.