Low profile dual frequency magnetic radiator for little low earth orbit satellite communication system

• US 7,227,506 B1
• Filed: 09/07/1999
• Issued: 06/05/2007
• Est. Priority Date: 07/08/1999
• Status: Expired due to Term

• Current Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Original Assignee: ViaSat Incorporated
• Inventors: Lewis, Donald Ray Jr.
• Primary Examiner(s): Ho; Tan
• Application Number:
  US09/391,267
• Time in Patent Office: 2,828 Days
• Field of Search: 343/700.MS, 343/767, 343/770, 343/713, 343/872
• US Class Current: 343/767
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/357 using a single feed point
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements

Abstract

A dual-frequency antenna (100) includes a ground plane (105) that is substantially planar and a radiator (110) that is substantially planar and formed of a conductive material. A slot (115) having first and second ends is formed in the radiator (110), and first and second apertures (120, 125) are formed at the first and second ends, respectively, of the slot (115). The radiator (110) also includes transmission connections (140) for coupling to external transmission circuitry and receiving connections (130) for coupling to external reception circuitry. The transmission connections (140) and the receiving connections (130) are located along the slot and separated by a distance of approximately one-quarter wavelength. Preferably, the height of the antenna (100), i.e., the distance between the radiator (110) and the ground plane (105) is equal to or less than about 1.9 centimeters for low-profile mounting on truck-drawn trailers.

Claims

1. A dual-frequency antenna, comprising:

a ground plane that is substantially planar; and

a radiator that is substantially planar, formed of a conductive material, and coupled to the ground plane, the radiator having formed therein a slot having first and second ends, a first aperture formed at the first end of the slot, and a second aperture formed at the second end of the slot, the radiator comprising a transmitting terminal and a receiving terminal formed along the slot and separated by a distance of approximately one-quarter wavelength.

2. The dual-frequency antenna of claim 1, wherein the conductive material is copper.

3. The dual-frequency antenna of claim 1, wherein the conductive material is aluminum.

4. The dual-frequency antenna of claim 1, wherein:

the ground plane is substantially parallel to a plane in which the radiator is held.

5. The dual-frequency antenna of claim 4, wherein the ground plane is held a predetermined distance from the radiator.

6. The dual-frequency antenna of claim 5, further comprising:

conductive fasteners for electrically coupling the radiator to the ground plane; and

a spacer for holding the ground plane the predetermined distance from the radiator.

7. The dual-frequency antenna of claim 6, wherein the spacer comprises a foam spacer.

8. The dual-frequency antenna of claim 6, wherein the ground plane comprises a portion of an external vehicle to which the dual-frequency antenna is mounted.

9. The dual-frequency antenna of claim 1, further comprising:

a radome for covering the radiator.

10. The dual-frequency antenna of claim 9, wherein the radome is formed from an electrically insulative material.

11. The dual frequency antenna of claim 1, further comprising:

a substrate mounted to the radiator for transmitting electrical signals to the radiator from an external device.

12. The dual-frequency antenna of claim 11, wherein the substrate comprises:

a first conductive region coupled to a region on a first side of the loaded slot of the radiator; and

a second conductive region coupled to a region on a second side of the loaded slot, opposite the first side, of the radiator;

a nonconductive region separating the first conductive region and the second conductive region; and

a capacitor electrically coupled between the first conductive region and the second conductive region.

13. The dual-frequency antenna of claim 1, wherein the radiator is configured to transmit radio frequency signals of about 150 MHz.

14. The dual-frequency antenna of claim 1, wherein the radiator is configured to receive radio frequency signals of about 137 MHz.

15. A dual-frequency antenna, comprising:

a ground plane that is substantially planar; and

a radiator that is substantially planar, formed of a conductive material, and coupled to the ground plane, the radiator having formed therein a slot having first and second ends, a first aperture formed at the first end of the slot, and a second aperture formed at the second end of the slot, the radiator comprising a transmitting terminal and a receiving terminal formed along the slot and separated by a distance of approximately one-quarter wavelength,

wherein the distance between the ground plane and the radiator is less than or equal to about 2.54 centimeters.