Waves Guided by a Boundary with Time-Space Periodic Modulation

摘要

Electromagnetic waves guided by a plane surface impedance which is modulated periodically in time and space in the traveling-wave sense are considered. The problem treated is a linearized statement of the nonlinear parametric interaction of waves on an open wave guide structure. In this linear treatment the rigorous approach formerly used on (purely spatial) periodic structures is taken. Parametric wave interactions of both the stable and the (potentially) unstable type are examined. The regions of operation for bound surface waves, as opposed to (radiating) leaky waves are determined rigorously for this structure. A region of operation called herein the 'sonic' region is found which represents a form of an electromagnetic shock wave. This sonic regions precludes, for the model chosen, the possibility of traveling-wave amplification along the length of the structure. The above mentioned results are forthcoming only from the complete treatment, including the effects of all time-space harmonics, carried out below. Finally, the power mixing principle for all harmonic waves is determined to be the Manley-Rowe power-frequency relation applied at the boundary surface. (Author)