An Ultra-wideband High-radiated-efficiency Tightly Coupled Dipole Array Integrated With Non-foster Circuits

This paper presents a new method to design a tightly coupled dipole array (TCDA), which can obtain ultra-wideband characteristics while maintaining high radiation efficiency. In this method, an active artificial magnetic conductor (AAMC) with a positive-slope reflection phase is constructed by loading non-foster circuits, and the AAMC is used to replace PEC as the ground plane. The bandwidth ratio of the proposed TCDA reaches 12: 1(0.187-2.23GHz) for VSWR<2.6 with the ± 60° scanning range in E-plane, and the average radiation efficiency across the whole frequency band and scanning range is higher than 92%. Besides, the overall profile of the array is $0.069 \lambda_{low}, \lambda_{low}$ is the wavelength corresponding to the lowest operating frequency.