Figure 4
Laboratory experiments. (a) Schematic of the experimental apparatus. (b–f) Transmission coefficients, \(S_{21}\), in dB scale measured along a coaxial 1-D waveguide as a function of the element position. The waveguide has an inter-element distance of \(d=30\) mm, submerged in (b) free space and (c–f) an aqueous solution. The medium conductivity is (b) \(\sigma _m=0.055\), (c) \(\sigma _m=1.5\), (d) \(\sigma _m=4\), and (e) \(\sigma _m=10\) S/m.
