Just to clarify after seeing several posts below. The magnetic and electric near fields fall off from 1/r^3 to 1/r^2, depending on component. The far fields f

Just to clarify after seeing several posts below. The magnetic and electric near fields fall off from 1/r^3 to 1/r^2, depending on component. The far fields fall off at 1/r, hence the familiar 1/r^2 for power (not amplitude). http://www.rfcafe.com/references/electrical/near-far-field.htm http://www.rfcafe.com/references/electrical/near-far-field.h... This thing operates in the near field, so it is pretty much useless past a distance of a coil diameter.