Variations of microwave transmission coefficient through Fe films and Fe/Cr superlattices have been studied caused by ferromagnetic resonance at frequencies from 26 to 38 GHz. The shape of resonance line is described in frames of the model where its asymmetry is obtained by adding of lorenzian dispersion line to the absorption line. It has been shown that the shape of resonance line for superlattices with continuous Fe and Cr layers and also for Fe films is well described in this model. For the superlattices with thin Fe or Cr layers only qualitative agreement is observed. In magnetic fields less than the field of ferromagnetic resonance, essential distinction is observed of experimental magnetic field dependence of transmission coefficient comparing to the model, for superlattices which have giant magnetoresistive effect.

The microwave giant magnetoresistance effect in a (CoFe/Cu) superlattice with micron-sized holes has been studied. Measurements of the frequency dependences of the transmission coefficient, as well as the dependences of the microwave transmission and reflection coefficients on the magnetic field, are performed. The measurements were performed on the superlattice samples without holes, having one hole with a diameter of 6.3 m and seven holes with a diameter of 1.7 m. It is shown that the presence of a hole with a diameter of 6.3 m leads to a significant frequency dependence of the microwave giant magnetoresistance effect. Magnetic and magnetoresistance measurements of superlattice samples were performed.