Propagation through a Rectangular Waveguide with Periodic Cross-section

Abstract

The propagation constant of a rectangular waveguide with sinusoidally varying cross-section (width) has been determined by numerically solving a second-order differential equation having periodic co-efficients. The solution of the equation is plotted against the distance along the direction of propagation over the entire period of the periodic structure. Making use of the plot, the phase or the propagation constant for a loss-less case has been obtained. The frequency dependence of this constant is then studied to evaluate other important and useful characteristics of the periodic structure e.g., phase velocity, group velocity, stop band, pass band, cut-off frequency, axial variation of the electric field etc. An experimental verification of some of the theoretical results has been presented.

Indexing Terms:

• Periodically-Loaded Structures
• Propagation Constant
• Numerical Solution of Wave Equation