Communication via leaky cables

• US 5,465,395 A
• Filed: 01/27/1994
• Issued: 11/07/1995
• Est. Priority Date: 04/22/1991
• Status: Expired due to Fees

• Current Assignee: Hunting Engineering Ltd. (Martin Marietta Corporation)
• Original Assignee: Hunting Engineering Ltd. (Martin Marietta Corporation)
• Inventors: Bartram, David V.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Pham, Chi H.
• Application Number:
  US08/187,817
• Time in Patent Office: 649 Days
• Field of Search: 455/55.1, 174/102 R, 174/102 SP, 174/106 R, 343/770, 343/790, 343/791, 343/873, 333/237
• US Class Current: 455/523
• CPC Class Codes: H01Q 13/203 Leaky coaxial lines
• CPC Class Codes: H04B 5/28 using the near field of leaky cables, e.g. of leaky coaxial cables

Abstract

A communication system that utilises leaky feeder cables (1) has a ruggedised tubular housing (8). The housing is preferably made of stainless steel, and to enable ingress and egress of signals the housing is provided with discontinuities. The discontinuities are preferably arranged to establish a regular pattern on the signals.

Claims

1. A wide band RF mobile communication system comprising:

at least one mobile station;

a continuous installation duct;

a coaxial leaky feeder cable acting as a transmitting and receiving antenna for RF signals;

the installation duct comprising a continuous rugged tube with the leaky feeder cable disposed longitudinally in loosely spaced relationship within the installation duct and withdrawable for inspection and replacement,

and in which the duct comprises substantially perfect RF screening material with relatively widely spaced discontinuities enabling egress and entry of wideband RF radiation to and from said coaxial leaky feeder cable, the discontinuities being disposed to define a filterable pattern on RF radiation incident upon the leaky feeder cable.

2. The wideband RF mobile communication system of claim 1 in which said discontinuities in the duct are 0.02 meters in length.

3. The wideband RF mobile communication system of claim 1 in which said discontinuities in the duct are arranged in a regular pattern to impose time delay periodicity on signals received by the leaky feeder via individual discontinuities.

4. The wideband RF mobile communication system of claim 1 in which one end of said leaky feeder cable is connected to a transmitter and the other end is connected via a low loss cable to a receiver.

5. The wideband RF mobile communication system of claim 1 in which said discontinuities comprise apertures in the duct.