Numerical Simulation of a Gyromagnetic NLTL Using an LC Discrete Line Model

Recent studies carried out in Brazil and in other countries such as the United States, Russia, Ukraine and, China have shown that a continuous nonlinear transmission line (also known as gyromagnetic) can generate high power radio frequency for various applications, such as in mobile defense platform, in the interruption of communication in battlefields, as well as in satellites and space vehicles, using a compact system with reduced size and weight. With this motivation, this article analyzes the nonlinear effect generated by the variation of length and number of sections in a continuous line modeled as a periodic structure of LC cells in series with voltage sources expressed by the one-dimensional (1D) gyromagnetic equation of Landau –Lifshitz–Gilbert (LLG) [1] . The results obtained through computational numerical simulation in Mathematica Software showed that the amplitude and modulation voltage depth(VMD) increases with the increase in length. In contrast, the precession frequency generated by the LLG equation does not depend on line length, but it must be lower than the Bragg frequency since a dispersive LC line behaves like a low-pass filter. Furthermore, the number of sections must be selected so that the results observed in the modeling can faithfully reproduce the physical processes that occur in the gyromagnetic continuous line [2] - [3] .