Textile Characterization for Wearable Antenna Application Using Transmission Line Method

This proposed work introduces the textile characterisation analysis based on the effects of fabric thickness and dielectric properties using the transmission line method for a wearable textile antenna. The return loss (S11) and transmission loss (S21) were analysed for denim, felt and Tencel in correlation with the conductivity properties using Computer Simulation Technology with Rogers 5880 as the reference sample. By varying the fabric thickness from 0.5 mm to 4 mm, the optimum thickness and type of fabric can be identified from the S11 and S21 parameters. In the transmission line simulation, the sample-under-test is a stripline with the conductivity values from 10-2 to 108 S/m. Results are further plotted against the thicknesses to observe the behaviour of all three textiles samples. The results show that Felt substrate with 3 mm thickness give the best performance. The felt substrate demonstrates the best transmission performance judging from the lowest transmission loss due to the low tangent loss followed by Tencel and denim. For accuracy analysis, the actual and calculated conductivity were also presented to show the textiles performance at low and high region of conductivity. The study reveals the importance of choosing the correct substrate with suitable dielectric and electrical properties before being implemented into the antenna design for good efficiency

Textile Characterization for Wearable Antenna Application Using Transmission Line Method

This proposed work introduces the textile characterisation analysis based on the effects of fabric thickness and dielectric properties using the transmission line method for a wearable textile antenna. The return loss (S11) and transmission loss (S21) were analysed for denim, felt and Tencel in correlation with the conductivity properties using Computer Simulation Technology with Rogers 5880 as the reference sample. By varying the fabric thickness from 0.5 mm to 4 mm, the optimum thickness and type of fabric can be identified from the S11 and S21 parameters. In the transmission line simulation, the sample-under-test is a stripline with the conductivity values from 10-2 to 108 S/m. Results are further plotted against the thicknesses to observe the behaviour of all three textiles samples. The results show that Felt substrate with 3 mm thickness give the best performance. The felt substrate demonstrates the best transmission performance judging from the lowest transmission loss due to the low tangent loss followed by Tencel and denim. For accuracy analysis, the actual and calculated conductivity were also presented to show the textiles performance at low and high region of conductivity. The study reveals the importance of choosing the correct substrate with suitable dielectric and electrical properties before being implemented into the antenna design for good efficiency

Multilayer hairpin bandpass filter for digital broadcasting / Robi'atun Adayiah Awang … [et al.]

A design of multilayer hairpin bandpass filter at digital broadcasting frequency has been presented. This filter has been presented based on the design specification together with the analyses of the response on the parameter sweeps of coupling gap, width and length of the resonators, metal thickness, substrate thickness and the measurement result of the fabricated circuit. This research has proposed 2.45-2.53 GHz bandpass filter using hairpin resonator in multilayer configuration for digital broadcasting application. The four-pole hairpin resonators centered at 2.5 GHz with bandwidth less than 100 MHz were designed. The best return and insertion losses in the passband are -42.96 dB and -2.55 dB, respectively. Combination of hairpin resonator operating at desired frequency has been optimized and simulated on Flame Retardant 4 (FR-4) with dielectric constant 4.6 together with the analysis using Computer Simulation Technology (CST). Design filter has been fabricated and measured using Network Analyzer and have a good agreement with simulated response. The measurement results of Sn and S21 obtained from the fabricated circuit are -19.56 dB and -7.64 dB, respectively. The analyses have proven that the design work according to the microwave theory. In addition it was observed that a wider bandwidth was achieved by increasing the number of resonators