PARAMETER EXCITATION OF ALFVEN AND HELICON WAVES IN A MAGNETOACTIVE COMPENSATED SEMICONDUCTOR BY MICROWAVE-RADIATION - COMMENT

The solution of the linearized kinetic equation used by Mamun et al. [ Phys. Rev. B 44, 8685 (1991)] is incorrect, since it is derived using an unjustified approximation that conflicts with the ordering given in the paper itself. This solution, in contrast with the standard gyroki netic one, exhibits no features essential for a magnetized plasma. The refore, it cannot be employed as a basis for the construction of the n onlinear response as well as for obtaining the linear dispersion relat ion.