Method and apparatus for mitigating interference from terrestrial broadcasts sharing the same channel with satellite broadcasts using an antenna with posterior sidelobes

• US 7,917,080 B2
• Filed: 07/11/2007
• Issued: 03/29/2011
• Est. Priority Date: 12/03/1999
• Status: Expired due to Fees

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Anderson, Paul R.
• Primary Examiner(s): Pan; Yuwen
• Application Number:
  US11/827,259
• Publication Number:
  US 20090004967A1
• Time in Patent Office: 1,357 Days
• Field of Search: 455/3.2, 455/3.02
• US Class Current: 455/3.02
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system

Abstract

An apparatus for simultaneously receiving a first signal from a non-terrestrial source and a second signal from a terrestrial source on the same or overlapping channels using a receive antenna with posteriorly-directed sidelobes is disclosed. The apparatus comprises at least one terrestrial transmitter transmitting information on at least one frequency simultaneously usable by at least one satellite transmitting to a satellite receive antenna having a sensitivity characterizable by a primary sensitive axis directed substantially at satellite. The terrestrial transmitter includes a azimuthal gain characteristic directed substantially away from the Earth'"'"'s Equator. In an alternative embodiment, the terrestrial transmitter is disposed at a location defining a vector angularly displaced from the primary sensitive axis by an angle of less than 90 degrees.

A method of transmitting information is also disclosed. In this method the information is transmitted on at least one frequency simultaneously usable by at least one satellite transmitting to a satellite receive antenna having a sensitivity characterizable by a primary sensitive axis directed substantially at the satellite and a posterior secondary sensitive axis. The method is performed by transmitting the information from a terrestrially-based transmitter to a terrestrial receive antenna in a direction substantially away from the Equator.

Claims

1. An apparatus capable of substantially simultaneous and non-interfering reception of a first signal transmitted on a channel from a non-terrestrial source and a second signal transmitted on the channel from a terrestrial source, comprising:

a first antenna, having a primary sensitive axis directed substantially at the non-terrestrial source and at least one secondary sensitive axis directed away from the primary sensitive axis by a first angle greater than 90 degrees; and

a second antenna having a sensitive axis directed away from the primary sensitive axis by a second angle less than 90 degrees;

wherein the second angle comprises a second angle azimuth component and a second angle elevation angle component, and wherein the second angle azimuth component is between approximately −

90 and 90 degrees and the second angle elevation component is between approximately 10 and 90−

δ

degrees, wherein δ

describes and angle from due South to a vector from the satellite receive antenna to the satellite.

2. The apparatus of claim 1, wherein second angle is between approximately 10 degrees and 90 degrees.

3. The apparatus of claim 1, wherein the second angle is approximately 10 degrees.

4. The apparatus of claim 1, wherein the first angle is between approximately 96 and 132 degrees.

5. The apparatus of claim 1, wherein the second antenna is disposed proximate the first antenna.

6. The apparatus of claim 1, wherein the non-terrestrial source is a satellite.

7. The apparatus of claim 6, wherein the satellite is disposed in a substantially geosynchronous orbit.

8. The apparatus of claim 6, wherein the satellite is disposed in a substantially geostationary orbit.