Perturbation Approach to Reconstructing Deformations in a Coaxial Cylindrical Waveguide

Abstract EN

We study a detection method for continuous mechanical deformations of coaxial cylindrical waveguideboundaries, using perturbation theory.

The inner boundary of the waveguide is described as a continuousPEC structure with deformations modeled by suitable continuous functions.

In the present approach,the computation complexity is significantly reduced compared to discrete conductor models studied inour previous work.

If the mechanically deformed metallic structure is irradiated by the microwave fieldsof appropriate frequencies, then, by means of measurements of the scattered fields at both ends, wecan reconstruct the continuous deformation function.

We apply the first-order perturbation methodto the inverse problem of reconstruction of boundary deformations, using the dominant TEM-mode ofthe microwave radiation.

Different orders of Tikhonov regularization, using the L-curve criterion, areinvestigated.

Using reflection data, we obtain reconstruction results that indicate an agreement betweenthe reconstructed and true continuous deformations of waveguide boundaries.