Measurement of the stochastic electromagnetic field coupling to an unshielded twisted pair cable

Measurements of the field-to-wire coupling to an unshielded twisted pair of wires have been carried out in a reverberation chamber. The wires were twisted as a helix around a dielectric support and placed inside the chamber´s working volume. The coupled voltage at one end of the line was measured by amplitude and phase for different pitch lengths, frequencies, and terminations of the other end using a vector network analyzer. To connect the symmetric wire pair with the asymmetric input of the analyzer a balun was used. For comparison with simulations, the quality factor of the chamber was determined from the coupling between two antennas. The measurements were done for different stirrer positions and the results were analyzed statistically.