| 摘要 |
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.
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