Passive intermodulation distortions induced by ferromagnetic materials at GSM frequencies

The problem of intermodulation distortions introduced by ferromagnetic materials inclusions in the construction of equipment used for transmission and processing of GSM signals is addressed. A Rayleigh model is implemented for determination of the response of ferromagnetic materials to two-tone signals. Results of experiments performed on coaxial transmission lines built with ferromagnetic materials and fed with two-tone signals are reported and compared to the predictions of the models.