Accession Number : AD0656424

Title :   LEAKAGE OF ELECTROMAGNETIC ENERGY FROM COAXIAL CABLE STRUCTURES,

Corporate Author : ARMY SIGNAL ENGINEERING LABS FORT MONMOUTH N J

Personal Author(s) : Ikrath,Kurt

Report Date : 1957

Pagination or Media Count : 131

Abstract : Starting with a general discussion of the field relations involved in the guidance of electromagnetic energy by cylindrical structures, the non-ideal boundary problem for a common coaxial cable is presented. Complete solutions for the outside leakage fields in terms of the cable voltage or cable currents have been derived for solid-wall shielded cables. The underlying conditions and the method of approach are thoroughly discussed and numerical examples are given. The physical significance of the solutions is demonstrated by showing the amount of power 'guided' along the outside of the cable as a function of the power flowing inside of the cable. The similarity of the leakage energy transmission phenomena with that of Sommerfelds' wire surface waves is emphasized. Formulas for the leakage fields emanating from braided cables are derived. The underlying concepts are discussed and the physical significance of the solutions is explained. Magnitude and polarization of the leakage fields emanating from braided cables are shown as a function of frequency by specific numerical examples. Formulas obtained in this way are of great value for further experimental work in this direction because they explain the generally observed but not well understood variation of the leakage as a function of frequency, with distance as a parameter. Measures regarding the suppression of electromagnetic leakage through mesh wire shields, e.g., cable braids, as well as the utilization of this type of leakage for wave launching devices are suggested. (Author)

Descriptors :   (*COAXIAL CABLES, LEAKAGE(ELECTRICAL)), ELECTROMAGNETIC PROPERTIES, RADIOFREQUENCY POWER, ELECTROMAGNETIC FIELDS, BOUNDARY VALUE PROBLEMS, TRANSMISSION LINES, WAVE PROPAGATION, MATHEMATICAL ANALYSIS

Subject Categories : Electrical and Electronic Equipment
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE