Recharacterizing non-TEM mode propagation

The authors present theoretical aspects which characterize electromagnetic propagation of observed planewaves produced by an X-band open ended waveguide in the radiating zone, at angular offsets which are roughly the halfwidth of the beam generated by the transmitting waveguide. Elements of wave propagation are presented where the magnitude of the Poynting vector propagates with the magnitude of the intrinsic velocity in a direction of interest different from the direction of propagation of the Poynting vector of the uniform TEM (transverse electromagnetic) plane wavefront. Equations are derived which suggest that decreased energy density propagates with an energy transport velocity equal to the magnitude of the phase velocity. The theory presented here agrees with experimental observations.<>