Multiple beam antenna system for simultaneously receiving multiple satellite signals

• US 5,495,258 A
• Filed: 09/01/1994
• Issued: 02/27/1996
• Est. Priority Date: 09/01/1994
• Status: Expired due to Fees

• Current Assignee: Dovedale Investments Ltd.
• Original Assignee: Nicholas L. Muhlhauser
• Inventors: Muhlhauser, Nicholas L., Weakley, Thomas C., Townley, Scott A.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): LE, HOANGANH T
• Application Number:
  US08/299,376
• Time in Patent Office: 544 Days
• Field of Search: 343/753, 343/789, 343/895, 343/754, 343/844, 343/850, 343/853, 342/361, 342/362, 342/375, 342/371, 342/372, 342/373
• US Class Current: 343/753
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 11/083 Tapered helical aerials, e.g. conical spiral aerials
• CPC Class Codes: H01Q 21/0037 linear waveguide fed arrays
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 25/008 lens fed multibeam arrays
• CPC Class Codes: H01Q 3/40 with phasing matrix

Abstract

A multiple beam array antenna system including a first group of right-handed circularly polarized subarrays and a second group of left-handed circularly polarized subarrays. Combined signals from the right-handed subarrays are output via low noise amplifiers to a first electromagnetic lens while the outputs of the left-handed circularly polarized subarrays are sent via low noise amplifiers to a second steering electromagnetic lens. A satellite selection matrix output block allows a user to tap into signals from right-handed circularly polarized satellites, left-handed circularly polarized satellites, and linearly polarized satellites. A plurality of satellites (e.g. right-handed satellite "A" and linearly polarized satellite "B") may be accessed simultaneously thus allowing the user to utilize both signals at the same time.

Claims

1. A multiple beam array antenna system for receiving electromagnetic polarized signals from different satellites, said system comprising:

first and second subarrays of circularly polarized helical antenna elements, said first subarray of antenna elements being right-handed circularly polarized and said second subarray of antenna elements being left-handed circularly polarized;

first and second signal summing waveguides, the received electromagnetic signals from said first subarray being summed in said first waveguide and the received electromagnetic signals from said second subarray being summed in said second waveguide;

first and second low noise amplifiers, the summed signal from said first subarray and said first waveguide being amplified by said first amplifier and the summed signal from said second subarray and said second waveguide being amplified by said second amplifier;

first and second electromagnetic lenses for allowing multiple signals to be received by said multiple beam array antenna system, said summed right-handed circularly polarized signal amplified by said first amplifier being sent to said first electromagnetic lens and said summed left-handed circularly polarized signal amplified by said second amplifier being sent to said second electromagnetic lens whereby said first lens acts upon received right-handed circularly polarized signals and said second lens acts upon received left-handed circularly polarized signals so that said system can receive both right and left handed circularly polarized signals and thereafter output their content.

2. The antenna system of claim 1, wherein said first subarray includes at least four right-handed helical antenna elements and said second subarray includes at least four left-handed helical antenna elements and wherein each of said first and second subarrays are non-symmetrical so as to radiate or receive fan-shaped beams, and said first and second subarrays operate at substantially equal frequencies.

3. The antenna system of claim 2, wherein each of said antenna elements of said first and second subarrays includes a tapered dielectric mandrel with a conductive winding wound around its outer periphery in a helical manner, and wherein each of said antenna elements of said first and second subarrays is mounted on a mounting plate within a conductive cup aperture.

4. The antenna system of claim 3, wherein each of said mandrels includes an impedance matching extension portion protruding from its base for insertion into one of a plurality of mounting apertures defined within said mounting plate, and wherein a conductive member extends from said conductive winding on the mandrel outer periphery through said extension portion and said mounting aperture and into or adjacent the waveguide for the subarray so as to allow the received signals to make their way from said conductive winding into said waveguide.

5. The antenna system of claim 3, wherein said antenna elements of said first subarray are spaced apart from about 0.5λ

to 2.0λ and

said antenna elements of said second subarray are also spaced apart from about 0.5λ

to about 2.0λ

, and wherein said first subarray antenna elements are spaced from said second subarray antenna elements by about 0.5λ

to 2.0λ

.

6. The antenna system of claim 1, wherein said antenna elements making up said firsthand second subarrays are designed to receive satellite television signals from about 10.7-13 GHz, and wherein said system can simultaneously receive two of:

(i) right-handed circularly polarized signals;

(ii) left-handed circularly polarized signals; and

(iii) linearly polarized signals.

7. The antenna system of claim 6, wherein said system scans a fan-shaped beam extending from about 2°

-5°

in the East-West direction and from about 5°

-10°

in the North-South direction, and wherein the array of antenna elements has a directivity of from about 29-32 dBi.

8. An array antenna receiving system comprising:

a first group of right-handed circularly polarized subarrays, each such subarray having a plurality of right-handed circularly polarized helical antenna elements;

a second group of left-handed circularly polarized subarrays, each such left-handed subarray having a plurality of left-handed circularly polarized helical antenna elements;

wherein said subarrays of said first and second groups are arranged in an interleaved or alternating fashion and receive substantially the same frequencies;

a first electromagnetic lens for receiving signals from said first group of subarrays and a second electromagnetic lens for receiving signals from said second group of subarrays; and

means for manipulating said first and second electromagnetic lenses so as to enable said system to receive right-handed circularly polarized signals, left-handed circularly polarized signals, and linearly polarized signals within the scanning field of the system.

9. The system of claim 8, further including means for simultaneously receiving both circularly polarized signals and linearly polarized signals and outputting said simultaneously received signals to a user.