Double Negative Metasurface Wideband Antenna Design Using TCM-Based Optimization for 5G Sub-6 GHz Applications

This paper presents a compact, multiband, flexible metasurface (flexi-meta) antenna structure consisting of metasurface antenna elements designed exclusively for 5G sub-6 GHz applications. The proposed flexi-meta antenna is realized by first creating a double-negative (DNG) metamaterial unit cell on a flexible (0.4 mm thick) FR-4 substrate. Then, an array of these DNG unit cells is suitably placed inside the rectangular ring-slotted patch using the Theory of characteristic modes (TCM), to achieve optimal performance in the sub-6 GHz band. The resulting flexi-meta antenna is compact with an overall volume of 300 mm 3 ([Formula: see text]). It exhibits a wide bandwidth of 1100 MHz (3.15–4.25 GHz), a peak gain of 5.5 dBi, a return loss of [Formula: see text] dB, and a radiation efficiency of 85%. These characteristics distinguish the flexi-meta antenna as cost effective, compact, conformal, high-performance contender for 5G sub-6GHz and IoT applications.