Flat cable crosstalk

QuickField simulation example

We take a 28 AVG 0.050" pitch flat ribbon cable as a test model. Two wires carry a high frequency signal. The potentials of adjacent wires are measured.
To reduce the crosstalk the victim line can be screened off by the grounded wire. The idea of this example is taken from the How to minimize crosstalk in cable designs blog post by Collin Wells from Texas Instruments.

Problem Type
Plane-parallel problem of AC conduction.

Geometry

Given
Relative permittivity of insulation ε = 2;
Frequency f = 1 MHz.

Task
Calculate the induced voltage in the victim line.

Solution
We apply potential difference of ~2V at the signal line. The induced voltage in the victim line is measured in two cases: the intermediate strand is grounded, and the intermediate strand is insulated (floating conductor).

Results
Induced voltage in the victim line is 71 mV. The grounded wire helps to reduce the induced voltage down to 16 mV.

• Download simulation files (files may be viewed using any QuickField Edition).