Antenna for air-to-ground communication

• US 6,735,438 B1
• Filed: 08/14/2000
• Issued: 05/11/2004
• Est. Priority Date: 08/14/2000
• Status: Expired due to Fees

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Sabatino, Anthony
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): MILLER, BRANDON J
• Application Number:
  US09/638,231
• Time in Patent Office: 1,366 Days
• Field of Search: 455/427, 455/431, 455/11.1, 455/12.1, 455/13.3, 455/422.1, 455/448, 455/13.2, 455/562.1, 455/13.1, 343/705, 343/835, 343/874, 343/890
• US Class Current: 455/427
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service

Abstract

A system and method for providing wireless communication services to passengers of an aircraft through the use of a standard mobile telephone. A system of antennas on an air base station radiates above a horizontal plane in order to provide coverage for an aircraft flying through a service airspace. The air system may be conveniently overlaid on an existing terrestrial wireless system in order to share based station facilities. A stretched dome shaped antenna pattern provides 360 degrees of coverage in the horizontal plane. A cardioid direction antenna pattern in the horizontal plane provides coverage in a specific portion of the air space such as an air corridor. Various combinations of antennas, and transceivers are interconnected in order to provide the proper coverage, capacity and interference control requirements for a particular air cell.

Claims

1. A system for use in providing wireless communication service between a base station and an aircraft, the system comprising:

an antenna system disposed at the base station and producing a radiation pattern directed upward into an air space above the antenna system;

the radiation pattern defining a stretched dome shape;

the stretched dome shape defining a substantially circular pattern about an axis substantially normal to the surface of the earth and further defining a first surface portion closest to the axis but farthest from the surface of the earth and a second surface portion farthest from the axis but closest to the surface of the earth; and

in a plane normal to the surface of the earth, the stretched dome shape defining a variable radius of curvature extending from a largest radius of curvature at the first surface portion to a smallest radius of curvature at the second surface portion,

whereby, when the aircraft is disposed within the radiation pattern, signals may be communicated within the radiation pattern between the base station and the aircraft.

2. The system of claim 1, wherein the antenna system comprises a plurality of antenna elements.

3. The system of claim 1, wherein the antenna system consists of a single antenna element.

4. The system of claim 1, wherein the antenna system is coupled to the base station.

5. The system of claim 1, further comprising an external antenna disposed on an exterior portion of the aircraft, whereby, when the external antenna is disposed within the radiation pattern, signals may be communicated within the radiation pattern between the base station and the external antenna.

6. A method of establishing a radiation pattern for use in providing wireless communication service between a base station antenna system and an aircraft, the method comprising:

radiating bi-directional signals between the base station antenna system and the aircraft in a stretched dome shaped radiation pattern directed upward into an air space above the base station antenna system,

wherein the stretched dome shape defines a substantially circular pattern about an axis substantially normal to the surface of the earth and further defines a first surface portion closest to the axis but farthest from the surface of the earth and a second surface portion farthest from the axis but closest to the surface of the earth, and

wherein, in a plane normal to the surface of the earth, the stretched dome shape defines a variable radius of curvature extending from a largest radius of curvature at the first surface portion to a smallest radius of curvature at the second surface portion.

7. The method of claim 6, wherein the bi-directional signal comprises a transmit signal and a receive signal, the method further comprising:

transmitting the transmit signal from at least one transmit antenna disposed at the base station; and

receiving the receive signal from at least one receive antenna disposed at the base station.

8. The method of claim 7, wherein the transmit signal defines a transmit signal strength, and the receive signal defines a receive signal strength, the method further comprising:

increasing the transmit signal strength in response to a determination that the receive signal strength is less than a first threshold level; and

decreasing the transmit signal strength in response to a determination that the receive signal strength is greater than a second threshold level.

9. An aircraft antenna system for providing wireless communication service between a base station and an aircraft, comprising:

the aircraft antenna system disposed at the aircraft and producing a radiation pattern directed into an air space below the aircraft;

the radiation pattern defining a stretched dome shape;

the stretched dome shape defining a substantially circular pattern about an axis substantially normal to the direction of flight and further defining a first surface portion closest to the axis but farthest from the aircraft and a second surface portion farthest from the axis but closest to the aircraft; and

in a plane normal to the direction of flight, the stretched dome shape defining a variable radius of curvature extending from a largest radius of curvature at the first surface portion to a smallest radius of curvature at the second surface portion,

whereby, when the base station is disposed within the radiation pattern, signals may be communicated within the radiation pattern between the base station and the aircraft.