Chaos Characteristics Analysis about Transient Signals of FH Radio with PLL Synthesizer

Chaos characteristic analysis of the phase-locked loop (PLL) synthesizer has been made in this paper based on the phase model of it, and we conclude the state equation of this model and the condition when the system becomes chaos. Because the parameters of the PLL synthesizer will be changed when the FH radio switch the frequency, the system may turn to be chaos caused by the parameters of it meet the very condition. Some analysis about the transient signals of the frequency-hopping (FH) radio with PLL synthesizer is made in this paper. The fractal dimension of the transient signals is estimated by Cao´s method, and the maximal Lyapunov exponent of these signals is positive. The unique double-ring attractor of them is also reproduced through the phase space reconstruction. All the result approve that the output of the FH radio is chaotic when the frequency changing.