“…As defined in the framework of the EMERALD project, the manufacturing process used to build up accurate ultra-wideband (UWB) phantoms has to be easily reproducible by an electrical engineer in a non-specific environment without extreme precautions, and to some extent at low cost. The specificity of the GeePs-L2S breast phantom and those suggested in our previous and current works on the head [ 19 , 32 ], breast [ 13 , 33 ], and thorax [ 34 , 35 ] phantoms, has been confirmed by the work of [ 14 , 15 , 16 , 17 , 18 ] and [ 36 , 37 , 38 , 39 ]. These phantoms composed of several 3D printed cavities are filled up with liquid mixtures made for example of Triton X-100 (TX-100, a non-ionic surfactant) and salt water, the concentrations are numerically adjusted so that the dielectric properties are close to the reference values over a wide frequency range.…”