The Methods of External Excitation for Analysis of Arbitrarily-Shaped Hollow Conducting Waveguides

Abstract

Abstract-A new numerical technique is proposed for analyzing arbitrary shaped hollow waveguides.The method is based on mathematically modelling of physical response of a system to excitation over a range of frequencies. The response amplitudes are then used to determine the resonant frequencies. The results of the numerical experiments justifying the method are presented. The method is validated by circular waveguide, rectangular waveguide an equilateral triangular waveguide. We apply the method for multi connected domains and for waveguides with boundary singularities like the Lshaped waveguide. Good agreements between the simulated and the published results have been obtained. The method does not generate spurious eigenfrequencies.

Solving Periodic Eigenproblems by Solving Corresponding Excitation Problems in the Domain of the Eigenvalue

“…Also, it is not necessarily required to observe the voltage across the port resistors. It is rather possible to work with some arbitrary observable of the field solution such as the electric field within the solution domain or some integral measure of it (as for instance suggested in [11,12]). A particular strength of this method is that the excitation can be chosen in a way that a desired eigenmode is more excited than others.…”

“…In [10][11][12], so-called methods of external and internal excitation are proposed for the solution of eigenproblems. These methods apply an excitation to the eigenproblem under consideration and observe a norm of the solution dependent on the varying eigenvalue.…”

“…The method is implemented together with two different regularization schemes. In [10,11] homogeneous waveguide problems and in [12] generalized Sturm-Liouville problems are considered. The particular property of these methods is that they do not require the solution of an algebraic eigenproblem, but the repeated solution of corresponding excitation problems.…”

“…Such methods can never focus the entire excitation energy into an isolated eigenfrequency and they are restricted by the always limited observation time, where even several eigenmodes have to be resolved simultaneously. In contrast, our method and the methods presented in [11,12] directly work in the domain of the eigenvalue and have thus the possibility to direct the entire excitation engergy into one isolated eigenmode. Moreover, not only eigenfrequencies are considered in this paper, but also complex propagation constants.…”

Influence of the Spot-Size and Cross-Section on the Output Fields and Power Density Along the Straight Hollow Waveguide

“…A numerical technique has been proposed for the analysis of various hollow conducting waveguides [11]. The method is based on mathematically modelling of physical response of a system to excitation over a range of frequencies.…”