A Wideband Grating Lobe Suppression Scheme Based on Array Factor Reconfiguration and Its Application in Multibeam Antenna Arrays

This paper presents an ultra-wideband E-plane multi-beam antenna array with broadband grating lobe suppression characteristics, operating in the band of 6-18 GHz. Firstly, a grating lobe suppression scheme based on array factor reconfiguration is proposed, along with the corresponding design guidelines. Secondly, based on an ultra-compact ultra-wideband Vivaldi antenna array, a parasitic array and coupling structure corresponding to the array factor reconfiguration scheme are designed, achieving significant grating lobe suppression. For the high port coupling caused by the ultra-compact spacing, a decoupling structure with almost no loss of antenna efficiency is also designed, which extends the antenna’s operating bandwidth by 25% in the lower band. To further enhance practicality, the array is cascaded with a Rotman lens, forming a highly integrated, low-cost, high-performance multi-beam system. The fabricated prototype, along with simulation and measurement results, demonstrates good consistency, validating the effectiveness of the proposed design.