The Nonlinearity Distortion Analysis And Simulation Of RF Network

Modern digital communication is developing towards increasingly complex modulating scheme and high-power. More and more RF power device were pushed into nonlinear region because of pursuing of low consume and high band-width. It is becoming more and more important to the availability using of device working in nonlinear region. S-parameters ever played very important role in electronic measurement. The theory based on S-parameters results in a revolution of micro-electronics industry. However, S-parameters are applicable only if the superposition theorem holds, or in other words if the device or system behaves linear and aren't applied for analyzing nonlinear system. A technology of Large-Signal Network Analysis Going beyond S-parameters is extensively developed.In this paper, researching from the basic concept of Large-Signal Network Analysis, we discuss the complex and intractability problems of nonlinear microwave systems measurements. Envelope domain technology is a very important concept and analysis method of LSNA technology. We discuss concept and analysis method of envelope domain and demonstrate how apply the method for analyzing RF nonlinear system, explaining the worsen effect of nonlinear distortion in the communication system through simulating constellation, power spectrum and bit-error-ratio of system. Each response elements of fifth-order nonlinear system excited with a two-tone are derived. Based on CDMA signal passed through the nonlinear fifth-order amplifier, closed-form expressions for the ACPR are derived by using power series and high order cumulation, and the analytical results are compared with the simulation results of third-order nonlinear analysis and practical measurement, in order to demonstrate validity of the algorithm.