A Wide-Angle and Ultrawideband Van Atta Array for Monostatic RCS Enhancement

The limited applications of current Van Atta arrays in various fields are primarily due to their narrow working bandwidths. This letter designed an ultrawideband Van Atta retrodirective array. It is based on the generalized phase conjugation principle and leverages the wideband characteristics of the Vivaldi antenna. This array exhibits excellent retrodirective performance over the frequency range of 2.42 GHz to 29.71 GHz, boasting a relative working bandwidth of 170%. To verify the design, a prototype was fabricated and its retrodirective performance was measured over the 2.42 GHz to 18.2 GHz frequency range. The measured results correlate well with the simulated ones. Specifically, the beamwidth remains within ±30°, and the variation in the monostatic radar cross section (RCS) value of the array does not surpass 3 dB. Compared to a metal plate of equal area, the monostatic RCS exhibits an enhancement of 10 dB to 20 dB. This design, with a wide bandwidth and wide-angle retrodirection capabilities, is poised to significantly impact the research and application of Van Atta arrays.