A compact circularly-polarized conformai antenna using an anisotropic artificial ground

In this paper, we present the design, fabrication, and measurement of a compact circularly-polarized conformal antenna employing a finite-sized anisotropic artificial ground plane. The antenna structure consists of a loop monopole on the top and a metallic sheet backed truncated metasurface on the bottom, which are separated by a foam spacer. The metasurface contains an array of two by two loop resonators with a pair of corners chamfered as well as a pair of slots cut into the inner periphery. The integrated antenna, operating at the 2.4 GHz ISM band, has stable characteristics in terms of the input impedance, axial ratio, and gain under structural deformation. A prototype of the antenna was fabricated and characterized, showing a good agreement between simulated and measured results.