Change of electrical characteristics of radiofrequency cables under thermal effect
Abstract
Four basic temperature dependent electrical parameters of rf cables are described by expressions which facilitate an analysis of their sensitivity to temperature effects, these parameters being capacitance, wave impedance, attenuation factor and phase shift factor. Calculations for coaxial cables are based on an equivalent dielectric permittivity of the insulation system, including air gap between dielectric and outer conductor produced in the manufacturing process as well as the air gap between dielectric and inner conductor produced by variation of the radius of the latter. Mechanical strains affecting the system geometry are found from the solution to Lame's problem for thin walled cylinders and Hooke's law extended to a three dimensional state of stress. For illustration, numerical results are given for RK328Pr high precision cables with monolithic Teflon4D insulation (dielectric constant epsilon = 2.03 at 20 C).
 Publication:

USSR Rept Electron Elec Eng JPRS UEE
 Pub Date:
 January 1985
 Bibcode:
 1985RpEEE....R..14L
 Keywords:

 Attenuation Coefficients;
 Capacitance;
 Coaxial Cables;
 Electrical Impedance;
 Permittivity;
 Phase Shift;
 Temperature Dependence;
 Air;
 Dielectrics;
 Gaps;
 Hookes Law;
 Lame Functions;
 Radio Frequencies;
 Electronics and Electrical Engineering