RADIATING COAXIAL CABLE AND METHOD OF MANUFACTURE THEREOF

• US 3,691,488 A
• Filed: 09/14/1970
• Issued: 09/12/1972
• Est. Priority Date: 09/14/1970
• Status: Expired due to Term

• Current Assignee: Alfred G. Jr. Holtum
• Original Assignee: Alfred G. Jr. Holtum
• Inventors: Holtum, Alfred G. Jr.
• Primary Examiner(s): Saalbach, Herman Karl
• Assistant Examiner(s): Punter, Wm. H.
• Application Number:
  US05/071,804
• Time in Patent Office: 729 Days
• Field of Search: 343/770,771,905 333/95A,96,95S
• US Class Current: 333/237
• CPC Class Codes: H01B 11/1808 Construction of the conductors
• CPC Class Codes: H01B 13/225 Screening coaxial cables
• CPC Class Codes: H01Q 13/203 Leaky coaxial lines
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

The crests of the corrugated outer conductor of a coaxial cable are partially removed along the length of one portion of its circumference to produce apertures in the corrugation crests while leaving the corrugation roots intact. The cable is thus made '"'"''"'"''"'"''"'"'leaky'"'"''"'"''"'"''"'"' for use as a radiator for tunnel communications systems and the like. Desirable aperture sizes and shapes are described.

Claims

1. A radiating high-frequency transmission element for tUnnel communications and the like comprising an elongated transversely corrugated conducting tube having longitudinally aligned apertures in all corrugation crests, the corrugation roots being unapertured.

2. The radiating transmission element of claim 1 wherein the conducting tube is the outer conductor of a coaxial cable.

3. The radiating transmission element of claim 2 having a foam dielectric within the outer conductor.

4. The radiating transmission element of claim 1 having a low-loss dielectric sheath encasing the corrugated tube.

5. The radiating transmission element of claim 1 having the apertures of generally oval shape.

6. The radiating transmission element of claim 1 comprising a corrugated generally circular tube having at least one portion of the circular periphery thereof cut away from circularity along its entire length to form the apertures.

7. The transmission element of claim 6 wherein the transverse shape is free of concavities.

8. The transmission element of claim 6 wherein the apertures are of a width from one-half to twice the distance of the spacing therebetween.

9. The radiating high-frequency transmission element of claim 1 comprising a corrugated foam-dielectric coaxial cable having generally oval-shape apertures in the corrugation crests and enclosed in a low-loss dielectric sheath.

10. In a method of making a radiating high-frequency transmission element for tunnel communications and the like, the improvement comprising removing at least one angular sector of all the corrugation crests of a corrugated high-frequency transmission element while leaving the corrugation roots intact.

11. The improved method of claim 10 wherein the transmission element is substantially circular and said sector of the corrugation crests is removed by cutting away a circumferential portion leaving the transverse shape free of concavity.

12. The improved method of claim 10 including the added step of thereafter encasing the element in a low-loss dielectric sheath.