In this work, we delve into the structure of some typical microwave ferrites while investigating the propagation of nonlinear circularly polarized waveguide excitations. In the standpoint, we consider a ferromagnetic slab insulator of 0.5 mm thickness submitted to an external transverse magnetic field.Combining the Landau-Lifshitz-Gilbert formalism of evolution of the magnetization to Maxwell equations, we survey the interaction process of an electromagnetic wave perturbation with the slab. As a result, using the perturbative scaling approach suitable to high-frequency excitations, we derive some new evolution system describing the propagation of circularly polarized waves in the medium. Pursuing further with the analysis, we unwrap the integrability properties of the new system using the singularity structure method where sufficient arbitrary functions are generated. Taking advantage of such properties, we construct a rich variety of nonlinear excitations, solutions to the ferrite dynamics. Additionally, we address some physical implications of the results obtained previously.