Plural frequency antenna feed
First Claim
1. A method of communicating two different electromagnetic wave signals having frequencies falling within two different frequency bands via a single antenna, the method comprising the steps of:
- providing a first waveguide for concurrently carrying first and second electromagnetic signals without interference therebetween, the first signals having a frequency in a first band and the second signals having a frequency in a second band different than the first band;
locating a second waveguide adjacent and parallel to said first waveguide;
aligning a series of coupling holes defined in said second waveguide with a series of holes defines in said first waveguide; and
dielectrically loading said second waveguide with dielectric material extending along said second waveguide opposite said holes to inhibit the first signals from passing between the first and second waveguides and for facilitating communication of the second signals between said first and second waveguides.
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Accused Products
Abstract
Apparatus and method for providing an antenna feed (10) operative at different microwave frequency bands employ a circular waveguide (14) interconnecting an orthomode transducer (20) to a feed horn (16) thereby providing a feed (10) suitable for illuminating the reflector (54) of an antenna (12). The orthomode transducer provides for a coupling of waves in the first frequency band with both vertical and horizontally polarized waves. Included within the feed is a coupler assembly (26) of waves of the second frequency band operative via a sidewall of the circular waveguide. The coupler assembly includes plural identical coupling sections (28) each having a rectangular waveguide section contiguous and parallel to the circular waveguide with a row of apertures for coupling power into and out of the circular waveguide. Pairs of the coupling sections are disposed in orthogonal planes so as to introduce two linearly polarized waves which are perpendicular to each other. A slab (48) of dielectric material is placed in each of the coupling sections to match the phase velocity of waves in the coupling sections to waves in the circular waveguide at the second frequency band while mismatching the phase velocities at the first frequency band. The dispersion of the waveguides provides for interaction with electromagnetic waves in the second frequency band while inhibiting such interaction at the first frequency band.
227 Citations
21 Claims
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1. A method of communicating two different electromagnetic wave signals having frequencies falling within two different frequency bands via a single antenna, the method comprising the steps of:
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providing a first waveguide for concurrently carrying first and second electromagnetic signals without interference therebetween, the first signals having a frequency in a first band and the second signals having a frequency in a second band different than the first band; locating a second waveguide adjacent and parallel to said first waveguide; aligning a series of coupling holes defined in said second waveguide with a series of holes defines in said first waveguide; and dielectrically loading said second waveguide with dielectric material extending along said second waveguide opposite said holes to inhibit the first signals from passing between the first and second waveguides and for facilitating communication of the second signals between said first and second waveguides. - View Dependent Claims (2, 3)
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4. An antenna feed operative for propagating signals comprising:
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a transducer for generating first signals having a frequency in a first frequency band; a circular waveguide coupled to the transducer; a horn coupled to the circular waveguide opposite the transducer; first and second waveguides at least partially disposed adjacent said circular waveguide, the first and the second waveguides being spaced apart from each other by 90 degrees in a circumferential direction around said circular waveguide, each of the first and second waveguides having a series of coupling holes extending into said circular waveguide for coupling second signals between the first and second waveguides and the circular waveguide, the second signals having a frequency in a second frequency band different from the first frequency band; and first and second dielectric slabs respectively disposed in the first and second waveguides, the first and second dielectric slabs respectively inhibiting the first signals from entering the first and second waveguides from the circular waveguide while respectively facilitating coupling of the second signals between the first and second waveguides and the circular waveguide whereby the first and second signals can traverse the circular waveguide concurrently without interference therebetween. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An antenna feed operative for propagating signals comprising:
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a transducer for generating first signals at a first frequency falling within a first frequency band; a circular waveguide coupled to the transducer; a horn coupled to the circular waveguide opposite the transducer; a first waveguide at least partially disposed adjacent said circular waveguide, the first waveguide having a series of coupling holes extending into said circular waveguide for coupling second signals between the first waveguide and the circular waveguide, the second signals having a frequency falling within a second frequency band; and means for respectively inhibiting the first signals from entering the first waveguide from the circular waveguide while respectively facilitating coupling of the second signals between the first waveguide and the circular waveguide whereby the first and second signals can traverse the circular waveguide concurrently without interference therebetween and wherein the first and second frequency bands are separated by at least 7 GHZ.
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Specification