Development of planar antennas with textile metamaterial substrate in the 5G frequency band for WBAN applications
Microstrip Antenna, Textile antenna, WBAN, Textile metamaterial, 5G.
The incessant development of implanted or promoted biometric sensors has led to the growth of Wireless Body Area Network (WBAN) technology. A WBAN can be used for many applications, such as monitoring of physiological signals and industrial communication applications. In this context, the textile antenna is an important element in wireless communication in smart fabrics, being the subject of recurrent research in industrial, military and medical applications. These antennas are flexible and, therefore, become convenient in applications where antenna rigidity is an obstacle This work presents the development of planar antennas with a textile metamaterial substrate in the 5G frequency range for WBAN applications, showing all process from making the substrates to the manufacture and testing of the antennas. Three types of textile substrate with different structure and composition were selected, and in each of them a conductive thread was inserted through different techniques (manual insertion, knitting and automatic sewing). The characterization of the materials was performed using simulations in the HFSS and the coaxial probe method, to obtain the electrical parameters. The antennas were designed and simulated to operate at 3.5 GHz, the best results being manufactured and tested in a Vector Network Analyzer (VNA). The results obtained in the simulations and tests were analyzed and the presence of a metamaterial characteristic was found in the loop and straight stitch geometries. Antennas with a textile metamaterial substrate had a lower resonance frequency than those with a dielectric textile substrate, indicating the possibility of reducing the dimensions of the device.