In a casual discussion about the methods for transmitting RF waves in free space, someone asked why the antenna produces an electric field instead of using a loop to produce a magnetic field.
My response was that the permeability of free space (an empty vacuum) is optimum for the electric field component rather than for the magnetic component which requires permeability similar to iron or an other ferrous material.
Since a vacuum has excellent permeability for the electric field, but poor permeability for the magnetic field, the optimum antenna for electromagnetic waves would be some kind of an air gap rather than a loop of wire.
My response was that the permeability of free space (an empty vacuum) is optimum for the electric field component rather than for the magnetic component which requires permeability similar to iron or an other ferrous material.
Since a vacuum has excellent permeability for the electric field, but poor permeability for the magnetic field, the optimum antenna for electromagnetic waves would be some kind of an air gap rather than a loop of wire.