V.N. Gavriushin, A.A. Golovkov

Formed and solved a system of algebraic equations that satisfy the criteria of a frequency dependence of the modules and phase transfer functions of amplifiers and frequency demodulators different options to include pole nonlinear element and parallel to the voltage feedback as a whole in relation to the four-resistor for which are found as a result of the optimal relationship between transfer matrix elements. These relationships are used to form the second algebraic equations whose solutions are possible to obtain mathematical expressions to determine the optimal values of two-terminal resistive impedance of two-model schemes. We also obtain the mathematical model of jet-ports in the form of sets of expressions to determine the optimal dependence of the resistance of the frequency. The values of the parameters of quasi-two-poles, providing match the characteristics of real-governmental with optimal characteristics in a limited frequency band. It is shown that the frequency characteristics of the studied devices, resulting in the mathematical modeling of the system «Mathcad» and circuit simulation in the system «Orcad», are in satisfactory agreement.