A novel low-RCS antenna array based on integration of electromagnetic metasurface and conventional antenna

Aiming at obtaining low scattering antenna array, in this paper a novel method of integrating electromagnetic metasurface with conventional antenna is proposed. The theoretical analysis and practical implementation of this method are presented. Using this method, a novel antenna array is obtained by connecting partial unit cells of metasurface with transmission line and adopting coaxial excitations. In the radiation mode, the metasurface is excited and radiates effectively. Besides, the array has almost the same performance as the conventional array. In the scattering mode, this array demonstrates low in-band RCS due to the scattering cancellation of middle metasurface and other surrounding structures. Using this method, a 2 × 1 array, as an example, is designed and numerically analyzed. The results show that the array has the well-behaved radiation performance and low RCS property. The working principle of the proposed array is illustrated by investigating the current and resultant field. Further analysis also reveals the effecting law of metasurface unit cells in antenna's radiation and scattering performance. Therefore, flexible designs can be obtained to fit different requirements. Finally, experiments are conducted. And the good agreement between computations and measurements further verifies the validity of the proposed design. Moreover, the proposed method also features easy implementation and high integrity and can be extended to the designing of large scale array antennas.