Aperture Coupling and Dipole Excitation in Planar Waveguide Partially Filled With Left-Handed Material

We present physical concepts and formulations for a parallel-plate waveguide which is partially filled with stratified right-handed and left-handed media and fed by apertures. Based on an exact analysis, high power transmissions can be obtained if the medium parameters and layer thicknesses are properly chosen. Such a structure is called a super waveguide since the transmitted power is extremely larger than that in a conventional air-filled waveguide. The equivalence principle and stratified medium theory are used to set up the integral equation in terms of the magnetic currents on apertures. We have applied the method of moments to discretize the integral equation and solved it numerically. The impact of such magnetic currents to the high-power transmission and their interaction to the original dipole source are investigated. From numerical results, we notice that the transmission power is not as high as we anticipated if the source is outside the waveguide. If the source is placed inside the waveguide through apertures, however, the super waveguide will be realized.