Space-based tethered phased-array antenna

• US H1,383 H
• Filed: 03/31/1992
• Issued: 12/06/1994
• Est. Priority Date: 03/31/1992
• Status: Abandoned Application

• Current Assignee: Cynthia King, Michael Kaplan
• Original Assignee: Cynthia King, Michael Kaplan
• Inventors: Kaplan, Michael, King, Cynthia
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US78/686,65
• Time in Patent Office: 980 Days
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

An unsupported, flexible, quasi-linear phased-array antenna within a space-based radar system which is tethered to a host satellite in free space. The antenna is formed by a plurality of antenna elements which are connected serially along a common axis. The antenna points in an Earth-pointing direction via gravity-gradient forces acting thereon. The phased-array antenna is capable of radiating a narrow electromagnetic beam in the end-fire direction along the array either in a spot or conical beam for detecting, identifying and tracking moving targets on or near the Earth'"'"'s surface. According to one aspect of the invention, the phased-array antenna forms an elongated conductor which moves through a magnetic field in space for generating electrical power.

Claims

1. A phased-array antenna for use in a space-based radar system that radiates a narrow, steerable, electromagnetic beam in a specified direction to detect, identify and track targets on or near the surface of the earth, said antenna comprising:

a plurality of antenna elements having a predetermined spacing from one another;

interconnecting means for operatively interconnecting said antenna elements to form an array having a proximal end operatively connected to a satellite and a distal end, said distal end being unsupported and unfixed; and

communications means disposed within said interconnecting means for conveying radar signals between said satellite and said antenna elements.

2. The phased-array antenna as in claim 1, further comprising a means for producing phase shift control signals for controlling the phase of said radar signals, thereby steering a resultant beam produced by said antenna.

3. The phased-array antenna system as in claim 1, wherein said antenna elements are non-rigidly connected by said interconnecting means such that said antenna is bendable both along its length and about said satellite.

4. The phased-array antenna as in claim 1, wherein said antenna elements are interconnected to form a substantially linear array.

5. The phased-array antenna system as in claim 1, wherein said predetermined spacing is between approximately 1/5 and 1/6 Γ

.

6. The phased-array antenna system as in claim 1, wherein said array of antenna elements radiates said electromagnetic beam in a substantially end-fire direction.

7. The phased-array antenna system as in claim 1, wherein said first and second antenna elements are cross-dipole radiating antennas.

8. A phased-array antenna for use within a space-based radar system which provides a steerable, end-fire, electromagnetic beam to detect, identify and track targets on or near the surface of the earth, comprising:

a plurality of antenna elements having a predetermined spacing from one another and receiving phase shifted radar signals so as to produce said beam; and

interconnecting means for operatively connecting said first and second antenna elements to form an array having a proximal end operatively connected to a satellite and a distal end, said distal end being unsupported and unfixed.

9. The phased-array antenna system as in claim 8, further comprising means for producing phase shift control signals for controlling the phase of said radar signals, thereby steering a resultant beam produced by said antenna.

10. The phased-array antenna system as in claim 9, wherein said predetermined spacing is between approximately 1/5 and 1/6 Γ

.

11. The phased-array antenna system as in claim 9, wherein said antenna elements are cross-dipole radiating antennas.