Radio navigation antenna system
AssigneeE-Systems, Inc.
InventorSidney Pickles
Life of this patent
Estimating the term…
Abstract
Tactical radio navigation systems provide bearing information to an interrogating aircraft in response to pairs of interrogation pulses received at a beacon transponder, such systems also provide distance measuring and identification information. To provide the required bearing information, pulses radiated from a central antenna array are modulated at a 15 Hz frequency and by a 135 Hz frequency, by reflector elements rotating around a stationary central radiator. A counterpoise system associated with the central radiator and the reflector elements uptilts the carrier frequency and the 15 Hz modulation. To provide more uptilt to the radiated signal and further decrease the total energy radiated below the horizon, a double circuit shield counterpoise is provided in the lower part of a radome assembly enclosing the antenna system.
Claims16
An antenna system for radiating energy above the horizon and energized from a radio frequency source, comprising in combination:
- a central radiator coupled to the radio frequency source,
- a first plurality of spaced, reflector elements radially positioned from said central radiator,
- a second plurality of spaced, reflector elements positioned between said central radiator and said first plurality of reflector elements,
- a first counterpoise system disposed around said central radiator for upwardly reflecting radiation from said central radiator, and
- a second counterpoise system axially displaced from said first counterpoise system for providing added uplift to radiated signals and decreasing the total energy radiated below the horizon, said second counterpoise system comprising
- an upper reflecting surface, and
- a lower reflecting surface mounted parallel to and electrically interconnected with said upper reflecting surface.
An antenna system for radiating energy above the horizon and energized from a radio frequency source, comprising in combination:
- a housing including a drive motor,
- a central radiator mounted to said housing to be fixed in position with respect thereto and coupled to the radio frequency source,
- a first plurality of spaced, reflector elements radially positioned from said central radiator,
- a second plurality of spaced, reflector elements positioned between said central radiator and said first plurality of reflector elements,
- support means for positioning said first and second plurality of reflector elements and coupled to the drive motor of said housing and rotated thereby to provide rotation of said reflectors around a central radiator for modulating the electromagnetic waves radiated therefrom,
- a first reflecting surface disposed at one end of said central radiator,
- a second reflecting surface mounted to said support means and disposed from said first reflecting surface and coupled thereto as a counterpoise for reflecting an upward radiation pattern from said central radiator,
- a third reflecting surface axially disposed from said first plurality of reflector elements, and
- a fourth reflecting surface positioned between said first plurality of reflector elements and said third reflecting surface and coupled thereto as a counterpoise for reflecting an upward radiation pattern from the antenna system.
Dependencies are inferred from the claim text.