Teledesic LLC

Asu Ram Jha

Mark Alan Sturza

James R Stuart

Douglas Gene Lockie

Edward F Tuck

Alison K Brown

David Palmer Patterson

Moshe L Liron

Vilnis G Grencions

Donald A Ashford

H Beat Wackernagel, Deceased

The Satellite Communication System disclosed in the specification is a dynamic constellation (C) of satellites (S). The present invention is capable of offering continuous voice, data and video service to customers across the globe on the land, on the sea, or in the air. The preferred embodiment of the invention comprises a low Earth orbit satellite system that includes 40 spacecraft (S) traveling in each of 21 orbital planes at an altitude of 700 km (435 miles). This relatively large number of satellites employed by the preferred embodiment was selected to provide continuous coverage of the Earth's surface at a high minimum mask angle (1230a) of forty degrees. Each of the individual 840 spacecraft (S) functions as an independent sovereign switch of equal rank which knows the position of its neighbors, and independently handles traffic without ground control. The satellites (S) are capable of transporting calls to millions of customers using portable (P), mobile (M) and fixed (F) residential and business terminals, and gateways (G) to public phone networks. The constellation uses the 20 and 30 GHz frequency bands for communications between Earth and the constellation (C), and the 60 GHz band for communicating among the satellites (S). The present invention is designed to support in excess of 2,000,000 simultaneous connections, representing over 20,000,000 users at typical business usage levels, and over 350 billion minutes of use per year. Only a system such as the preferred embodiment, which utilizes 840 satellites at a preferred minimum mask angle of forty degrees, can accomplish these challenging objectives.

Satellite communication system

Terrestrial antennas (10A, 10B, 10C and 10D) which are capable of transmitting and receiving radio signals directly to and from satellites in low Earth orbit are disclosed. The preferred embodiment of the invention employs circularly polarized, dual-frequency printed circuit antenna elements (136) measuring only a fraction of an inch in diameter. One embodiment (10A) includes an elevation array and an azimuth array which both reside on a trapezoidal, semi-conical housing that resembles a flattened pyramid. Both the top and the curved exterior of the pyramid support circular, slotted, printed circuit patches on their surfaces which bound individual radiating antenna elements (18). Since the entire antenna is only a few inches in diameter and is less than two inches high, it can be incorporated as an integral element of a telephone (T) or can be mounted at the end of a collapsible mast (CM). Other embodiments (10B, 10C, and 10D) of the invention employ hemispherical, cylindrical, and truncated hemispherical configurations. These unique antennas permit direct communication with satellites in low Earth orbit using the 20 and 30 GHz frequency bands. The antennas (10A, 10B, 10C and 10D) and their associated circuitry are sufficiently powerful to provide dependable service virtually anywhere on land, sea or in the air.

Terrestrial antennas for satellite communication system

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Cerritos, CA, United States of America

Asu Ram Jha