Satellite communication system with a sweeping high-gain antenna
First Claim
1. A satellite communication system comprisinga satellite that receives messages from one or more remote terminal units, the satellite having a high gain antenna with a field of view that sweeps a service area during a sweep period, such that within the sweep period, each of the one or more remote terminal units in the service area is within the field of view of the high gain antenna for an illumination period that is substantially less than the sweep period, and whereinthe one or more remote terminal units communicate via the satellite during the illumination period andthe high gain antenna sweeps the service area by a change of orientation of the satellite relative to the service area.
1 Assignment
0 Petitions
Accused Products
Abstract
The satellite communications system of this invention provides high-gain coverage to a wide geographic area with a minimum number of satellites. The satellites each include a high-gain antenna that periodically sweeps the satellite'"'"'s service area to receive the messages from remote terminal units within the entire service area. In order to provide high gain, the antenna is designed to have a narrow beamwidth in at least one dimension. To cover the entire area, the antenna'"'"'s field of view is swept across the entire service area. In the preferred embodiment, the antenna'"'"'s field of view is essentially rectilinear, having a narrow beamwidth in one dimension and a beamwidth that extends across the entire service area in the other dimension, such that the sweeping effect is akin to that of a common push-broom. Because of the high gain of the satellite antenna, communications via the satellite can be accomplished using a low-gain wide-beamwidth antenna at the remote terminal unit.
-
Citations
23 Claims
-
1. A satellite communication system comprising
a satellite that receives messages from one or more remote terminal units, the satellite having a high gain antenna with a field of view that sweeps a service area during a sweep period, such that within the sweep period, each of the one or more remote terminal units in the service area is within the field of view of the high gain antenna for an illumination period that is substantially less than the sweep period, and wherein the one or more remote terminal units communicate via the satellite during the illumination period and the high gain antenna sweeps the service area by a change of orientation of the satellite relative to the service area.
-
17. A method for satellite communication comprising the steps of:
-
sweeping a service area of a satellite with an antenna having a field of view substantially smaller than the service area by changing an orientation of the satellite relative to the service area; receiving one or more messages at the satellite from one or more remote terminal units when each of the one or more remote terminal units are within the field of view, and transmitting the one or more messages received from the one or more remote terminal units from the satellite to a ground station. - View Dependent Claims (18, 19, 20, 21, 22)
-
-
23. A satellite communication system comprising
a satellite that includes: -
one or more high gain antenna elements, a select one of the one or more high-gain antenna elements being configured as an active antenna, and a receiver that is configured to receive messages from one or more remote terminal units via the active antenna; wherein; the active antenna has a single field of view that sweeps a service area during a sweep period, such that within the sweep period, each of the one or more remote terminal units in the service area is within the single field of view of the high gain antenna for an illumination period that is substantially less than the sweep period, and the one or more remote terminal units communicate via the satellite during the illumination period, the one or more high gain antennas are fixedly attached to the satellite, and the active antenna periodically sweeps the service area via a rotation of the satellite relative to a path of travel of the satellite.
-
Specification