Slotted dielectric-lined waveguide couplers and windows
First Claim
1. Waveguide coupling apparatus for converting microwave energy in a circular waveguide propagating the HE11 mode to a suitable coaxial waveguide mode, each of said waveguide modes having a phase velocity associated therewith, said apparatus comprising:
- a circular waveguide;
a coaxial waveguide concentric with said circular waveguide and overlapping a portion of said circular waveguide, a common wall separating said circular waveguide from said coaxial waveguide, said common wall comprising an outer wall of said circular waveguide and an inner wall of said coaxial waveguide in the portion of overlap;
means for coupling the microwave energy in said circular waveguide to a corresponding mode in the coaxial waveguide, said coupling means including an array of N equally spaced axial slots placed in said common wall, where N is an integer, said slots being filled with a dielectric;
a dielectric lining on both sides of the common wall in the portion of overlap, the respective thicknesses of said dielectric lining on at least one side of the common wall being tapered to optimize the coupling and to cause an intersection of the phase velocities of the microwave energy propagating the respective waveguide modes in said circular and coaxial waveguides.
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Accused Products
Abstract
Dielectric-filled longitudinal slots in the common wall of concentric circular and coaxial dielectric-lined waveguides allow microwave energy to be efficiently coupled therethrough. Such couplers are used with megawatt level gyrotrons for varied applications. One application provides a double seal waveguide vacuum window with low reflections over a wideband of frequencies. Another application provides an output coupler and window for quasi-optical gyrotrons. Still another application provides a waveguide mode converter for converting high order microwave modes, as are commonly found in waveguide cavities of high power gyrotrons, to lower-order modes suitable for low-loss transmission, such as the HE11 mode.
238 Citations
39 Claims
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1. Waveguide coupling apparatus for converting microwave energy in a circular waveguide propagating the HE11 mode to a suitable coaxial waveguide mode, each of said waveguide modes having a phase velocity associated therewith, said apparatus comprising:
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a circular waveguide; a coaxial waveguide concentric with said circular waveguide and overlapping a portion of said circular waveguide, a common wall separating said circular waveguide from said coaxial waveguide, said common wall comprising an outer wall of said circular waveguide and an inner wall of said coaxial waveguide in the portion of overlap; means for coupling the microwave energy in said circular waveguide to a corresponding mode in the coaxial waveguide, said coupling means including an array of N equally spaced axial slots placed in said common wall, where N is an integer, said slots being filled with a dielectric; a dielectric lining on both sides of the common wall in the portion of overlap, the respective thicknesses of said dielectric lining on at least one side of the common wall being tapered to optimize the coupling and to cause an intersection of the phase velocities of the microwave energy propagating the respective waveguide modes in said circular and coaxial waveguides. - View Dependent Claims (2, 3, 4, 5)
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6. Waveguide window apparatus comprising:
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first waveguide coupling means for coupling microwave energy from a first circular waveguide to a coaxial waveguide; second waveguide coupling means for coupling microwave energy from said coaxial waveguide to a second circular waveguide; pressure tight sealing means for;
(a) sealing said first circular waveguide from said coaxial waveguide in the region of said first waveguide coupling means, (b) sealing said second circular waveguide from said coaxial waveguide in the region of said second waveguide coupling means, (c) sealing said coaxial waveguide from its surrounding environment and (d) sealing said first circular waveguide from said second circular waveguide; andabsorbing means positioned within said first and second circular waveguides and said coaxial waveguide for;
(a) preventing reflections of any microwave energy incident upon said first and second waveguide coupling means in unwanted modes, and (b) avoiding reflections of microwave energy not completely coupled through said first and second waveguide coupling means. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. Output coupler apparatus for coupling microwave energy out of a quasi-optical microwave resonator said microwave resonator including mirrors aligned to reflect resonating microwave energy therebetween, a first mirror having a diameter D, said coupler apparatus, comprising:
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a circular waveguide having a coupling end and an output end, said circular waveguide being adapted to propagate microwave energy in the HE11 mode, said circular waveguide further having an outside diameter approximately equal to the diameter D of said first mirror; a coaxial waveguide concentric with said circular waveguide and overlapping a portion of said circular waveguide proximate said coupling end, a common wall separating said circular waveguide from said coaxial waveguide, said common wall comprising an outer wall of said circular waveguide and an inner wall of said coaxial waveguide in the portion of overlap, the diameter D of said first mirror approximately matching the outside diameter of said common wall, said common wall being attached at one end to a back side of said first mirror, whereby a portion of the microwave energy resonating in said quasi-optical microwave resonator escapes over said first mirror and into said coaxial waveguide; means for coupling the microwave energy propagating in said coaxial waveguide to the coupling end of said circular waveguide, said coupling means including an array of N equally spaced axial slots placed in said common wall in the portion of overlap, where N is an integer, said slots being filled with a dielectric; and a dielectric lining on both sides of the common wall in the portion of overlap. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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21. Waveguide mode converter apparatus comprising:
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(a) a circular waveguide having a coupling end and an output end, said circular waveguide being adapted to propagate microwave energy in a first waveguide mode; (b) a first coaxial waveguide concentric with said circular waveguide and overlapping a first portion of said circular waveguide proximate said coupling end, a first common wall separating said circular waveguide from said first coaxial waveguide, said first common wall comprising an outer wall of said circular waveguide and an inner wall of said first coaxial waveguide in the first portion of overlap; (c) first coupling means for coupling microwave energy propagating in said first coaxial waveguide to a first waveguide mode in said circular waveguide, said first coupling means including an array of N equally spaced axial slots placed in said first common wall in the first portion of overlap, where N is an integer; (d) a coaxial waveguide extension connected to said first coaxial waveguide, an inner wall of said coaxial waveguide extension comprising an extension of said first common wall; (e) a second coaxial waveguide overlapping a second portion of said coaxial waveguide extension, a second common wall separating said coaxial waveguide extension from said second coaxial waveguide, said second common wall comprising an outer wall of said coaxial waveguide extension and an inner wall of said second coaxial waveguide; (f) second coupling means for coupling microwave energy propagating in a second waveguide mode in said second coaxial waveguide to said first coaxial waveguide, said second coupling means including an array of M equally spaced axial slots placed in said second common wall in the second portion of overlap, where M is an integer; and (g) means for separating TE and TM modes of microwave energy propagating through said mode converter apparatus; whereby microwave energy propagating in said second waveguide mode in said second coaxial waveguide is coupled to propagate in said first waveguide mode in said circular waveguide. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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Specification