A Conformal AMC-Backed Array of Moderate Gain, Broad Coverage and Wide Bandwidth

This paper presents a conformal array antenna for emergency communication applications. The array consists of six conformal AMC-backed Yagi antennas, for which approximately half-space beam coverage can be achieved via one-dimensional full-azimuthal beam switching. The Yagi antenna is comprised of a bowtie-shaped driven dipole and three directors with optimized lengths and spacing to achieve the desired radiation characteristics. To increase the gain and generate the oblique directional beam, the Yagi antenna is backed by an AMC reflector. To validate the design, a prototype of conformal array element was fabricated and measured. Experimental results have shown the proposed conformal antenna exhibit a bandwidth of 570 MHz at the $2.4-\text{GHz}$ band, a gain of 7.5 dBi and approximately half-space beam coverage. The superior performance has shown its huge potential in balloon-based emergency communication stations.