The solitonic regimes of signal's propagation in nonlinear waveguides are of practical interest from the point of view of creating communication systems with high speed of information transmission, that are resistant to interference. The active investigation of nonlinear waves takes place in the physics of magnetic phenomena. The waves in magnetic media are characterized by wide possibilities of dispersion varying. That allows us to provide the existance of the particular domains of the dispersion curves where the conditions of the modulational instability's (MI) observation are satisfied.

In the present work the results of the nonlinear effects' experimental observation in the microstrip line on the substrate of ferrite-dielectric magnetized parallel, along the strip, are discussed. Those effects take place in the domain near the lower frequency of the bandstop and are interpreted in the work as MI of the electromagnetic wave in the line. The MI phenomenon observation is significantly connected with the decay effects [9].