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US 7,746,190 B2Granted
Polarization-preserving waveguide filter and transformer
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsFelice M. Vanin, Edward J. Wollack
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Abstract
A microwave waveguide filter includes an input waveguide section, an output waveguide section, a plurality of resonator sections disposed between the input and output waveguide sections, and a plurality of coupling sections disposed on either side of each of the resonator sections. The input waveguide section, the resonator sections, and the output waveguide section have at least four fold symmetric quadruple ridge cross-sections and the coupling sections have at least four fold symmetric cross-sections.
Claims29
A waveguide filter, the waveguide filter comprising:
- an input waveguide section, the input waveguide section supporting two polarization modes that are degenerate in frequency;
- an output waveguide section;
- a plurality of resonator sections disposed between the input and output waveguide sections;
- a plurality of coupling sections disposed on either side of each of the resonator sections,
- wherein the input waveguide section, the resonator sections, and the output waveguide section comprise at least four-fold symmetric quadruple ridge cross-sections, the cross-sections being four-fold symmetrical along the axis of propagation, and the coupling sections comprise at least four-fold symmetric cross-sections such that polarization of each input mode is preserved.
2 more elements
A waveguide filter, the waveguide filter comprising:
- an input waveguide section, the input waveguide section supporting two polarization modes that are degenerate in frequency;
- an output waveguide section;
- a first at least four fold symmetric quadruple-ridge section adjacent the input waveguide section;
- a plurality of resonator sections disposed between the first quadruple-ridge section and the output waveguide section, a first resonator section being disposed adjacent the first quadruple-ridge section;
- a plurality of coupling sections alternately disposed between the resonator sections,
- wherein the input waveguide section, the resonator sections, and the output waveguide section have second, at least four-fold symmetric quadruple ridge cross-sections, the cross-sections being four-fold symmetrical along the axis of propagation,
- the coupling sections have at least four-fold symmetric cross-sections, and the first quadruple-ridge section adjacent the input waveguide section includes ridges having lengths that are less than lengths of ridges of the second quadruple ridge cross-sections,
- such that polarization of each input mode is preserved.
5 more elements
A transformer, the transformer comprising:
- a housing with an at least four fold symmetric interior perimeter, the housing including a number of sides, where the number of sides equals 2·2n, where n is an integer greater than or equal to 1;
- and
- four ridges disposed at ninety degree intervals inside the interior perimeter, each ridge comprising a series of steps.
An apparatus, the apparatus comprising:
- a waveguide filter, the waveguide filter comprising:
- an input waveguide section, the input waveguide section supporting two polarization modes that are degenerate in frequency;
- an output waveguide section;
- a first at least four fold symmetric quadruple-ridge section adjacent the input waveguide section;
- a plurality of resonator sections disposed between the first quadruple-ridge section and the output waveguide section, a first resonator section being disposed adjacent the first quadruple-ridge section;
- a plurality of coupling sections alternately disposed between the resonator sections,
- wherein the input waveguide section, the resonator sections, and the output waveguide section have second, at least four-fold symmetric quadruple ridge cross-sections, the cross-sections being four-fold symmetrical along the axis of propagation,
- the coupling sections have at least four-fold symmetric cross-sections, and
- the first quadruple-ridge section adjacent the input waveguide section includes ridges having lengths that are less than lengths of ridges of the second quadruple ridge cross-sections;
- and
- a transformer comprising an at least four fold symmetric quadruple ridge cross section having four ridges, each ridge comprising a series of steps wherein ridge length increases along a longitudinal axis in the house,
- wherein the second end of the transformer is fixed to the waveguide filter such that the four ridges of the transformer abut the quadruple ridge cross section of one of the input and output waveguide sections,
- such that polarization of each input mode is preserved.
10 more elements
An apparatus, the apparatus comprising:
- a waveguide filter, the waveguide filter comprising:
- an input waveguide section, the input waveguide section supporting two polarization modes that are degenerate in frequency;
- an output waveguide section;
- a plurality of resonator sections disposed between the input and output waveguide sections;
- a plurality of coupling sections disposed on either side of each of the resonator sections,
- wherein the input waveguide section, the resonator sections, and the output waveguide section comprise at least four-fold symmetric quadruple ridge cross-sections, the cross-sections being four-fold symmetrical along the axis of propagation, and the coupling sections comprise at least four-fold symmetric cross-sections;
- and
- a transformer comprising an at least four fold symmetric quadruple ridge cross section having four ridges, each ridge comprising a series of steps wherein ridge length increases along a longitudinal axis in the house,
- wherein the second end of the transformer is fixed to the waveguide filter such that the four ridges of the transformer abut the quadruple ridge cross section of one of the input and output waveguide sections,
- such that polarization of each input mode is preserved.
7 more elements
A waveguide structure, the waveguide structure comprising:
- a pair of quadruple ridge waveguide sections having at least four fold symmetry, the waveguide sections supporting two polarization modes that are degenerate in frequency, the four fold symmetry being along the axis of propagation;
- and
- a four fold symmetric evanescent section disposed between the pair of quadruple ridge resonator sections, the modes being evanescent along the axis of propagation.
Dependencies are inferred from the claim text.