Figure 3
(a) Simulated and measured performances of ( \({\mathrm{S}}_{11})\) and a digital photograph and simulated current distribution of the PFR. (b) EM performance of the sensor for different materials, \({\varepsilon }_{r0}=1 \left({f}_{r0}=5.770GHz\right)\), \({\varepsilon }_{r1}=5 \left({f}_{r1}=5.338GHz\right)\), \({\varepsilon }_{r2}=10 \left({f}_{r2}=4.909GHz\right)\), and \({\varepsilon }_{r3}=15 \left({f}_{r3}=4.595GHz\right).\)
