Application of Hospital Textile Materials as Dielectric Substrates on Frequency Selective Surfaces
: Textile substrates, textile frequency selective surfaces, textile antenna, electrical characterization.
This work presents the simulated and experimental analyses of antennas and frequency selective surfaces with textile substrates made of cotton and polyester, based on the technical standard ABNT NBR 13734: 2016 - Textile products for health, for operation on ISM 2,4 GHz frequency band. For the design of the antennas and selective surfaces in textile frequencies, three textile materials with different proportions of cotton and polyester were selected and, using the coaxial probe technique, the electrical characterization of the three textile materials was carried out to obtain the electrical permittivity and loss tangent as a function of electrical frequency. The experimental data resulting from the electrical characterization were exported to the commercial software ANSYS HFSS®. The antennas were designed for a fully filled ground plane and rectangular patch fed by a microstrip line, and their dimensions were determined from the Transmission Line Model. The reflection coefficient observed the experimental operation of the antennas within the range of interest as a function of frequency. The frequency-selective surfaces were designed with square spirals with optimized dimensions based on experimental data from the electrical characterization of textiles that were exported to the software. The transmission coefficient observed the practical operation of the frequency-selective surfaces within the range of interest as a function of frequency. For the frequency range of interest, the textiles presented uniformity in electrical permittivity and loss tangent, and all structures (antennas and frequency selective surfaces) operated within the 2.4 GHz ISM band.