초록 ▼

An improved very small antenna terminal (VSAT) dual-beam antenna system for use with user subscriber terminals that communicate with low-earth orbiting and other satellites. In one embodiment, the dual-beam antenna system has two offset Gregorian dual-reflector antennas that each has an ellipsoidal

An improved very small antenna terminal (VSAT) dual-beam antenna system for use with user subscriber terminals that communicate with low-earth orbiting and other satellites. In one embodiment, the dual-beam antenna system has two offset Gregorian dual-reflector antennas that each has an ellipsoidal subreflector and a rotatable paraboloidal reflector having a focus in common with a focus of the ellipsoidal subreflector. The rotatable paraboloidal reflector couples energy to and from the ellipsoidal subreflector. An RF feed system couples RF energy to and from the ellipsoidal subreflector. Rotating apparatus rotates the paraboloidal reflector and ellipsoidal subreflector together around an azimuth axis of the antenna. The rotating apparatus independently and simultaneously rotates the paraboloidal reflector about an axis between the paraboloidal reflector and ellipsoidal subreflector which points the antenna at an orbiting satellite. A controller is coupled to the rotating apparatus that controls rotation of the paraboloidal reflector and the antenna to point the antenna toward the orbiting satellite. The two antennas are preferably mounted side-by side and the one antenna is pointed at a first satellite while the second antenna tracks a rising satellite. A VSAT radio is automatically handed-off to the rising LEO satellite by switching it from the one antenna to the second antenna. Another embodiment may be used to track a inclined-orbit satellite having a figure-eight orbit, wherein the actuators move the antenna more slowly to track the satellite. Another embodiment employs a single antenna that is fixed relative to an orbiting satellite.

대표청구항 ▼

[ What is claimed is:] [1.] An antenna system for use in communicating with an orbiting satellite, comprising:an offset Gregorian dual-reflector antenna that comprises:an ellipsoidal subreflector;a rotatable paraboloidal reflector having a focus in common with a focus of the ellipsoidal subreflector

[ What is claimed is:] [1.] An antenna system for use in communicating with an orbiting satellite, comprising:an offset Gregorian dual-reflector antenna that comprises:an ellipsoidal subreflector;a rotatable paraboloidal reflector having a focus in common with a focus of the ellipsoidal subreflector and which couples energy to and from the ellipsoidal subreflector;an RF feed system for coupling RF energy to and from the ellipsoidal subreflector; andpointing apparatus for pointing the antenna at an orbiting satellite that comprises:rotating apparatus for rotating the paraboloidal reflector and ellipsoidal subreflector together around an azimuth axis of the antenna and for independently and simultaneously rotating the paraboloidal reflector about an axis between the paraboloidal reflector and ellipsoidal subreflector so as to point the antenna at an orbiting satellite; anda controller coupled to the rotating apparatus for controlling rotation of the paraboloidal reflector and the antenna to point the antenna toward the orbiting satellite.