A Wide-Angle Series-Fed Active Metasurface

Wide-angle radiation capability allows antenna systems have wide-angle coverage and provide spectral and angular diversity desirable to many wireless communication systems. Previous schemes have aimed to achieve wide-angle beamforming with a microstrip patch array, but they add considerable complication to the fabrication, weight and cost to the antenna array. In this paper, we demonstrate wide-angle beamforming with a series-fed active metasurface, which is achieved by proper design and concatenation of subwavelength spaced series-fed microstrip patches. The demonstrated active metasurface consists of 14 patch elements and the center-to-center distance between adjacent elements is less than 0.3 λ. The currents on the elements are tapered in a Taylor distribution. The designed metasurface radiates at ±70° in the elevation plane with a 3 dB beamwidth of 35° and a sidelobe level (SLL) of -8.69 dB. These meritorious characteristics of the proposed design demonstrate that the series-fed active metasurface has good prospect to simplify the communication systems and keep the wide-angle function simultaneously.