An improved formulation of an optimizing Rayleigh-Ritz technique for closed dielectric waveguide analysis

It is shown that use of the E/sub Z//H/sub Z/ formulation to describe the modes of the homogeneous rectangular waveguide leads to a relative convergence phenomenon as well as to incorrect loss calculations. The method is reformulated using an E/sub x//E/sub y//H/sub x//H/sub y/ description of the homogeneous modes. The formulation is validated for step-index waveguides through nonperturbational calculations of the propagation and attenuation constants of the round step-index dielectric waveguide. Comparison with the direct eigenvalue solution shows excellent agreement for the dominant and three higher-order modes. The formulation is validated for graded-index waveguides through calculation of the dispersion curves for three modes of a Gaussian-Gaussian graded-index channel waveguide. Comparison of the results with those of two other methods shows excellent agreement.<
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