Metamaterials for Wearable Textile Antennas: Materials, Structures, and Fabrication.

With the rapid development of wearable body-centric wireless systems, there is a growing demand for textile antennas with stable on-body performance, low profile, flexibility, and garment compatibility. Textile metamaterials provide an effective approach to address the limitations of conventional textile antennas by regulating antenna-body coupling, backward radiation, surface-wave propagation, frequency selectivity, local resonance, and polarization. Although existing reviews have discussed the mechanisms and structures of metamaterials, systematic discussions that connect metamaterial structures with textile materials, fabrication, and performance remain limited. This review summarizes representative metamaterials used in textile antennas and analyzes their roles in gain enhancement, SAR reduction, miniaturization, multiband operation, and polarization improvement. Common substrates, spacers, and conductive materials are further reviewed, together with fabrication methods such as lamination, embroidery, sewing, weaving, knitting, printing, coating, and laser patterning. Current studies indicate that material variability, conductor loss, fabrication tolerance, layer alignment, deformation stability, and garment integration still restrict practical application. This review is expected to provide a reference for the design and realization of reliable metamaterials for textile antennas.