Inductance and Capacitance per Temperature

AI Thread Summary
The relationship between transmission speed in a cable and temperature is defined by the formula v=1/√(LC), where L is inductance and C is capacitance per unit length. Inductance and capacitance are expected to vary minimally with temperature changes from 20 to 50 degrees Celsius, particularly when using common dielectrics like PTFE. The dielectric properties play a crucial role in determining these variations, and significant changes are unlikely in this temperature range. For cables adhering to military specifications, relevant data can often be found in datasheets that cover a broader temperature range. Understanding these factors is essential for accurate assessments of transmission speed in varying thermal conditions.
americanforest
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I am studying the relationship between transmission speed in a Transmission Cable and the temperature of the cable. This speed is given by (as per discussion in the Feynman lectures)

v=\frac{1}{\sqrt{LC}} where
  • L is the inductance per unit length
  • C is the capacitance per unit length

Does anyone know how the inductance and capacitance are expected to vary with temperature? The range examined in the experiment is approximately 20-50 degrees Celsius.
 
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How much it will change basically depends on the properties of the dielectric (I am assuming you are referring to a coaxial cable).
The change should be very small assuming one of the more common dielectric is used, e.g. PTFE etc. I doubt creep will be much of an issue in such a small temperature range.

Also, if the range in question includes room temperature you should be able to find this data in a datasheet, they typically list data from -50 to +80 degrees C or so, at least if the cable conforms to military specs (and most coaxes do)
 
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