What is wave impedance?
This page describes basics of wave impedance with respect to propagation of electromagnetic waves.
As we know during EM wave(electromagnetic wave) propagation in a medium, changing magnetic field(H) produces electric field(E) and vice versa. The waves propagate due to two oscillating H and E fields. The region near to the source of radiation will experience high intensity of fields.
Wave impedance is defined by ratio of E and H.
Wave impedance = |E|/|H|
Wave impedance is high in the region where E is pre-dominant, for example straight wire fed by high impedance voltage driven source.
Wave impedance is low in the region where H is pre-dominant, for example loop/coil fed by low impedance current driven source.