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US 5,309,167 AGranted
Multifocal receiving antenna with a single aiming direction for several satellites
AssigneesThomson-LGT Laboratoire General des Telecommunications, Telediffusion de France
InventorsClaude Cluniat, Jean-Jacques Delmas
Life of this patent
Estimating the term…
Abstract
The receiving antenna comprises at least two sectors or sections of paraboloids focusing the radiation onto their axes at points F.sub.1 and F.sub.2 respectively offset by a whole number of wavelengths of the received radiation. Each sector or section is associated with a helicoidal source located in its focal zone and having the same axis as that of the corresponding sector.
Claims19
A multi-focal receiving antenna for receiving radiation of a predetermined wavelength, said antenna having a single aiming direction for more than one satellite, the antenna comprising:
- a reflector having at least two sectors of paraboloids, wherein respective axes of the paraboloids of the at least two sectors extend in a same direction with said at least two sectors having different focal points, and with the foci of said at least two sectors offset by a spacing equal to a whole number of wavelengths of the radiation of a predetermined wavelength to be received, said reflector having a quasi-flat structure with respect to a direction along said axes,
- said antenna further including a respective source for each of the at least two sectors for coupling the radiation, said sources located in zones of concentration of the radiation to be received, said sources merged with the respective axes of the at least two sectors of paraboloids, said sources respectively adapted for reception of differently polarized radiation;
- and
- wherein a first of said sectors is a sector of a paraboloid in which the paraboloid of the first of said sectors forms a central zone, and a second of said sectors is a sector of a paraboloid in which the paraboloid of the second of said sectors forms an external zone, and wherein said central zone is within said external zone.
1 more element
A multi-focal receiving antenna for receiving radiation of a predetermined wavelength, said antenna having a single aiming direction for more than one satellite, the antenna comprising:
- a reflector having at least two sectors of paraboloids, wherein respective axes of the paraboloids of the at least two sectors extend in a same direction with said at least two sectors having different focal points, and with the foci of said at least two sectors offset by a whole number of wavelengths of the radiation of a predetermined wavelength to be received;
- said antenna further including a respective source for each of the at least two sectors for coupling the radiation, said sources located in zones of concentration of the radiation to be received, said sources merged with the respective axes of the at least two sectors of paraboloids, said sources respectively adapted for reception of differently polarized radiation;
- and
- wherein a first of said sectors is a sector of a paraboloid which forms a central zone, and a second of said sectors is a sector of a paraboloid which forms an external zone, and wherein said central zone is within said external zone;
- wherein the sources are surface wave sources formed from helicoidal illuminators respectively connected to low noise amplifiers by coaxial cables;
- wherein two helicoidal illuminators are provided which are respectively adapted for the reception of right and left circular polarization components of the radiation;
- and
- wherein an electromagnetic absorber is disposed between the two helicoidal illuminators such that the helicoidal illuminator which is most distant from the reflecting surfaces of the sectors of paraboloids is not disturbed by a backward wave focused on the other helicoidal illuminator.
5 more elements
A multi-focal receiving antenna for receiving radiation of a predetermined wavelength, said antenna having a single aiming direction for more than one satellite, the antenna comprising:
- a reflector having at least two sectors of paraboloids, wherein respective axes of the paraboloids of the at least two sectors extend in a same direction with said at least two sectors having different focal points, and with the foci of said at least two sectors offset by a whole number of wavelengths of the radiation of a predetermined wavelength to be received;
- said antenna further including a respective source for each of the at least two sectors for coupling the radiation, said sources located in zones of concentration of the radiation to be received, said sources merged with the respective axes of the at least two sectors of paraboloids, said sources respectively adapted for reception of differently polarized radiation;
- and
- wherein a first of said sectors is a sector of a paraboloid which forms a central zone, and a second of said sectors is a sector of a paraboloid which forms an external zone, and wherein said central zone is within said external zone;
- wherein the sources are surface wave sources formed from helicoidal illuminators respectively connected to low noise amplifiers by coaxial cables;
- wherein two helicoidal illuminators are provided which are respectively adapted for the reception of right and left circular polarization components of the radiation;
- wherein the sectors of paraboloids have the same axis, which is also the axis of helicoids of the helicoidal illuminators, the foci of the sectors of the paraboloids being spaced on said same axis by K .lambda., and each sector having a symmetry of revolution about said same axis, wherein K is an integer and .lambda. is the wavelength of radiation to be received;
- and
- wherein one of the helicoids having the same axis is excited from a rear direction in a back-fire mode, and another helicoid is excited from an endward direction in an end-fire mode.
6 more elements
A multi-focal receiving antenna for receiving radiation of a predetermined wavelength, said antenna having a single aiming direction for more than one satellite, the antenna comprising:
- a reflector having at least two sectors of paraboloids, wherein respective axes of the paraboloids of the at least two sectors extend in a same direction with said at least two sectors having different focal points, and with the foci of said at least two sectors offset by a spacing equal to a whole number of wavelengths of the radiation of a predetermined wavelength to be received, said reflector having a quasi-flat structure with respect to a direction along said axes;
- said antenna further including a respective source for each of the at least two sectors for coupling the radiation, said sources located in zones of concentration of the radiation to be received, said sources merged with the respective axes of the at least two sectors of paraboloids, said sources respectively adapted for reception of differently polarized radiation;
- and
- wherein a first of said sectors is a sector of a first paraboloid, said first paraboloid forming a central zone, and the second of said sectors is a sector of a second paraboloid, said second paraboloid forming an external zone, and wherein said central zone is within said external zone,
- wherein said respective axes of the paraboloids of the first and second sectors extend along a common axis, with the foci of said first and second sectors spaced from each other on said common axis, and wherein a spacing between the respective foci of said first and second sectors along said common axis is equal to K.lambda., wherein K is an integer greater than zero, and .lambda. is the wavelength of radiation to be received.
2 more elements
A multi-focal receiving antenna for receiving radiation of a predetermined wavelength, said antenna having a single aiming direction for more than one satellite, the antenna comprising:
- a reflector having at least two sectors of paraboloids, wherein respective axes of the paraboloids of the at least two sectors extend in a same direction with said at least two sectors having different focal points, and with the foci of said at least two sectors offset by a spacing equal to a whole number of wavelengths of the radiation of a predetermined wavelength to be received, said reflector having a quasi-flat structure with respect to a direction along said axes,
- said antenna further including a respective source for each of the at least two sectors for coupling the radiation, said sources located in zones of concentration of the radiation to be received, said sources merged with the respective axes of the at least two sectors of paraboloids, said sources respectively adapted for reception of differently polarized radiation;
- and
- wherein a first of said sectors is a sector of a first paraboloid, said first paraboloid forming a central zone, and the second of said sectors is a sector of a second paraboloid, said second paraboloid forming an external zone, and wherein said central zone is within said external zone,
- wherein said first and second paraboloids have parallel axes including a spacing between said parallel axes, said spacing equal to K.lambda., wherein K is an integer greater than zero and .lambda. is the wavelength of radiation to be received.
2 more elements
A multi-focal receiving antenna for receiving radiation of a predetermined wavelength, said antenna having a single aiming direction for more than one satellite, the antenna comprising:
- a first plurality of sectors formed of a plurality of respective paraboloids forming a first family of paraboloids, wherein apices of the first family of paraboloids are offset by K,.lambda./2 with said first plurality of sectors focusing upon a first focal point, wherein K.sub.1 is an integer greater than zero;
- a second plurality of sectors formed of a second plurality of paraboloids with said second plurality of paraboloids forming a second family of paraboloids having apices offset by K.sub.2 .lambda./2 and with said second plurality of sectors focusing at a second focal point, wherein K.sub.2 is an integer greater than zero and .lambda. is the wavelength of radiation to be received;
- said antenna further including a respective source for each of the first and second plurality of sectors for coupling the radiation, said sources located in zones of concentration of the radiation to be received, said sources respectively adapted for reception of differently polarized radiations;
- wherein said first and second focal points are offset by a whole number of wavelengths of the radiation of a predetermined wavelength to be received, and wherein the axes of the first family of paraboloids and the axes of the second family of paraboloids extend in a same direction, with the multi-focal receiving antenna having a quasi-flat structure with respect to a direction along said axes.
1 more element
Dependencies are inferred from the claim text.