Use of Huygens’ principle for analysis and synthesis of the fields in oversized waveguides

Abstract

We develop a method based on Huygens' principle for calculation of the traveling-wave field in a cylindrical oversized waveguide with smooth and shallow wall corrugations with allowance for diffraction by the nonsymmetric end of the waveguide. Algorithms for synthesizing the specified field distribution on the surface of such a waveguide are proposed. The performed experiments confirm the adequacy of this approach for calculation of oversized electrodynamic systems.

Development of Mode Conversion Waveguides at KIT

“…Therefore a numerical method for the synthesis of mirror-line launchers has been developed at KIT [6]. This method is completely different from the numerical method presented in ref [5].…”

“…In the method shown in ref [5], 1) the analysis of the field on the launcher wall is based on the KirchhoffHuygens integral; 2) an amplitude distribution which covers several Brillouin zones on the launcher wall is used as the target function in the optimization of the launcher wall profile; 3) the wall profile is synthesized on each Brillouin zone one by one, and the wall deformation defined on a Brillouin zone is calculated according to the phase correction, where the phase correction is the sum of the phases of the forward propagated field and that of the backward propagated field on the Brillouin zone.…”

“…A method to synthesize the helical harmonic perturbation amplitudes has been developed to improve the Gaussian mode content of the wave beam at the aperture and to depress the field at the cuts [4]. In 2006, by use of the Huygens' principle, a numerical method was developed for the analysis and synthesis of oversized mirror-line launchers for high power gyrotrons [5]. Later in 2009 a completely different numerical method for the analysis and synthesis of the fields in such oversized mirror-line launchers has been developed at KIT [6].…”

Numerical Modeling of Millimeter-Wave Transmission Lines

“…This can be used for a fast mode (de)composition via a 2D FFT over the waveguide wall. This approach is decribed in [12], [13].…”

“…In ECRH transmission lines it emanates from a helically cut waveguide with wall perturbations that is driven by a rotating high-order TE mode [11], [13]. The field which is radiated from the helical cut can be calculated with the coupled mode approach [11] or with the scalar diffraction integral [13].…”