"And this means there can be no '
back-scattering,' which is what causes electrical resistance in conventional electrical conductors."
Shyamnath Gollakota and his colleague Joshua Smith have proved that weak radio signals can indeed provide all an Internet gadget needs, using a principle called
back-scattering. Instead of generating original signals, one of their devices selectively reflects incoming radio waves to construct a new signal--a bit like an injured hiker sending an SOS message using the sun and a mirror.
The analysis of the
back-scattering distributions on tissue optical properties allowed for revealing that the augmentation of the scattering coefficient increases the size of the surface laser spot, while the absorption coefficient decreases its size.
According to GTD theory, noisy radar target
back-scattering data can be expressed as follows:
Brown, "A numerical study of
back-scattering from time-evolving sea surfaces: Comparison of hydrodynamic models," IEEE Trans.
It means that the
back-scattering effect became more and more obvious.