Gyrotron whispering gallery mode coupler with a mode conversion reflector for exciting a circular symmetric uniform phase RF beam in a corrugated waveguide
AssigneeCalabazas Creek Research, Inc.
InventorJeffrey M. Neilson
Life of this patent
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Abstract
A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.
Claims19
A whispering gallery mode (WGM) coupler comprising:
- a corrugated waveguide having an entrance;
- a cylindrical waveguide for propagation of RF energy, the cylindrical waveguide having a sequence of deformations on an inner surface, each said deformation causing a focusing and guiding of incident RF energy to a subsequent deformation of said sequence of deformations;
- said cylindrical waveguide having a launch edge for directing RF energy in a quasi-optical mode to a mode conversion reflector;
- said mode conversion reflector having a first order surface profile for converting said quasi-optical mode RF energy into a circularly symmetric RF beam having a minimum diameter at the entrance of said corrugated waveguide;
- said mode conversion reflector also having a second order surface profile for providing a substantially uniform phase front of said circularly symmetric RF beam at said entrance of said corrugated waveguide.
A Whispering Gallery Mode (WGM) coupler for a gyrotron comprising:
- a WGM waveguide receiving high order mode radio frequency (RF) energy, the WGM waveguide having a succession of internal deformations for repeatedly focusing and guiding said high order mode RF energy which propagates therein and delivering said RF energy to a launch edge of said WGM waveguide as quasi-optical RF energy;
- a reflector receiving said quasi-optical RF energy from said launch edge;
- a corrugated waveguide receiving substantially quasi-optical RF energy reflected from said reflector;
- said WGM waveguide operative on at least one high order mode of said propagating RF energy;
- said reflector also having a first order correction for focusing said substantially quasi-optical RF energy into a substantially circular beam at the entrance of said corrugated waveguide;
- said reflector having a second order correction for phase correcting said substantially quasi-optical RF energy to have a substantially uniform phase at the entrance of said corrugated waveguide.
A whispering gallery mode (WGM) coupler comprising:
- a cylindrical waveguide having a sequence of deformations for focusing and guiding incident RF energy into one or more high order modes, said sequence of deformations selected to form beat wavelengths of said high order modes, said deformations causing a focusing and guiding of said incident RF energy to a launch edge, thereby forming a quasi-optical RF beam having a plurality of high order modes;
- a corrugated waveguide having an entrance;
- a phase transforming reflector receiving said quasi-optical RF beam having said plurality of high order modes, said phase transforming reflector forming a circularly symmetric RF beam having a substantially uniform phase at said entrance of said corrugated waveguide.
Dependencies are inferred from the claim text.