Table of Contents

Characteristic Cable Impedance
- Method 1: Measure C and L of a known cable length
  - Step 1: Measure capacitance
  - Step 2: Measure inductance

Characteristic Cable Impedance

Method 1: Measure C and L of a known cable length

For a transmission line:

Z0 = SQRT( L' / C' )

where:
L' = inductance per meter (H/m)
C' = capacitance per meter (F/m)

Step 1: Measure capacitance

Take a known cable length l. Leave the far end open-circuit. Measure the capacitance between center conductor and shield:

C′= C_measured / l

Step 2: Measure inductance

Short the far end. Measure the inductance seen from the near end. For a shorted transmission line at sufficiently low frequency:

L' = L_measured / l