Flexible dual-mode antenna for mobile stations

摘要

A dual-mode Mobile Station (MS) supports both a satellite mode and a cellular mode using a combined swivel-type cellular and satellite antenna. The combined antenna has on one end a quarter wave stub for the cellular mode, and at the other end a compressible quadrifilar helical antenna for the satellite mode. The satellite antenna is preferably made of a plastic film in the form of a cylinder, on which a metallized film is deposited. The plastic film is filled with a foam rubber that keeps its cylindrical form. In the cellular mode, the flexible satellite antenna is compressed between the main housing of the MS and a sliding lid on the side of the MS to occupy a volume that is only a fraction of its uncompressed volume. In the satellite mode, the lid is opened and the combined antenna is rotated 90 to 180 degrees, at which point the satellite antenna resumes its cylindrical form due to the foam rubber expanding or mechanical driving inside of the plastic film.