Solid Phantom for Body-Centric Propagation Measurements at 60 GHz

The first solid skin-equivalent phantom is developed to characterize the propagation channel for 60-GHz wireless body-centric systems. This phantom is designed to emulate the same reflection coefficient at the air/phantom interface as at the air/skin interface. It is fabricated by combining carbon black powder with polydimethylsiloxane (PDMS) and metallizing the resulting flexible carbon-PDMS composite on one side. Compared to the water-based semi-solid phantoms suffering from evaporation, this solid phantom allows avoiding the deterioration in time of the electromagnetic properties. This paper reports the design procedure and peculiarities of the phantom preparation. Using two open-ended waveguides, it is demonstrated, both numerically and experimentally, that the propagation along flat and cylindrical phantoms is similar to the propagation along the skin in the 58-63-GHz frequency range. The phantom is further validated using two dipoles and two wearable textile Yagi-Uda antennas demonstrating that it can be successfully used for propagation studies.