The survey of the radiotechnical methods for the nonlinear amplifiers analysis is conducted. The presentation of the nonlinear amplifier as typical radiotechnical link, consisting of input and output filters and inertionless nonlinear amplifier, is proposed. The methods of the identification of the radiotechnical link elements are described. The problem of registration of amplitude-to-phase conversion is discussed. The possibility of the successful description of the multifrequency working regimes of the microwave amplifiers using the proposed model is demonstrated.