Simulations of the Effects of Dual-Frequency Signal on the Nonlinear Element

Abstract

Due to the significant increase in the number of wireless devices in the conduct of development of modern telecommunication systems there are strict requirements on what should be the spectrum of the transmitted signal. This is because when there is a formation and amplification of the useful signal due to nonlinear characteristics of the transmission path there are different out-of-band radiation. Out-of-band components falling in the frequency region of the transmission channel, such as harmonics of the operating frequency, simply suppressed by the output filter. Intermodulation products of odd order, on the contrary, lie near the operating frequency and directly pass to the output of the transmitting device. The power amplifier is an important part of wireless data transmission, increase the power of the radio signal to the required level before it is broadcast. Currently, amplifiers are widely used transistors and integrated circuits. Nonlinear distortions occur due to the nonlinearity of current voltage characteristics of the amplifying elements (e.g., transistors) and are manifested in the distortion of the amplified signal. Transistor amplifier is a nonlinear element, and the methodology is considered, it can be used for other nonlinear elements used in transmitting and receiving devices. In the analysis of nonlinear circuits usually do not consider the processes occurring within the components of the circuit, and confined to their external characteristics. Usually this dependence of output current versus applied input voltage. Known solution to a model problem in which the coefficients of Berg in the case of single-frequency influence on the nonlinear element. Uses piecewise-linear approximation of current-voltage characteristics of the nonlinear element, i.e. during the analysis of the non linear element real feature is replaced by segments of straight lines with different slopes. In this work the developed methodology and the results of calculations of the coefficients of the Berg for dual-frequency input. The results can be useful in determining the spectral components of the signal in wireless communication systems is to find a compromise between the linearity of the system and its energy efficiency.