This paper introduces a decagonal C-shaped complementary splitring resonator (CSRR) textile-based metamaterial (MTM). The overall size of the proposed sub-wavelength MTM unit cell is 0.28λ0 ×0.255λ0 at 3 GHz. Its stopband behaviour was first studied prior analysing the negative index properties of the proposed MTM. It is worth noting that in this work a unique way the experiments were completed. For both simulations andmeasurements, the proposed MTM exhibited negative-permittivity and negative-refractive index characteristics with an average bandwidth of more than 3 GHz (considering 1.7 to 8.2 GHz as the measurements were carried out within this range). In simulations, the MTM exhibited negative-permittivity properties within the range of 1.7 to 7.52 GHz and 7.96 to 8.2 GHz; and negative-refractive index from 1.7 to 2.23 GHz and 2.33 to 5.09 GHz and 5.63 to 7.45 GHz. When measured from 1.7 to 8.2 GHz, negative-permittivity and negative-refractive index characteristics are exhibited throughout an average bandwidth of more than 3 GHz. Similarly, the transmission coefficient attained in simulations and measurements indicated about 3 GHz of bandwidth, from 1.7 to 3.88 GHz and from 6.68 to 7.4 GHz. The satisfactory agreement between simulations and experiments indicates the potential of the proposed MTM for microwave applications.
