Floating GPS Cylindrical Slot Antenna
This invention enhances the capabilities of the Buoyant Cable Antenna (BCA). An electrical prototype of a GPS antenna, suitable in size and shape for mounting on the end of a BCA has been developed. It's suitability for submersion in salt water combined with the ability to receive GPS signals both in air and in salt water make this technology distinctive. The electrical matching of the antenna to a transmission line demonstrates the ability to receive GPS data while mounted on an aluminum ground plane. This technology would satisfy any GPS application requiring an antenna which will float and operate in salt water.
The present invention comprises a cylindrical dielectric tube covered on the curved outer surface with a good conductor such as copper foil. A number of slots, preferably four, a half wavelength long at the frequency of interest, e.g., L1 or L2, are cut longitudinally in the foil. All of the slots are connected by a suitable power combiner. The antenna's feed line which is connected prior to the antenna being filled with dielectric keeps the water out of the cylindrical cavity and the slot. The slot which is not shorted by seawater because it is facing up receives the GPS signals. Electrically the antenna behaves similarly to a slot antenna cut into a cylindrical conducting tube operating in air. The unique Antenna technology has successfully received GPS signals in both air and salt water.
Dr. G. R. Jacobovitz
Phone: (443) 778-9899