The Research Of Frequency Hopping Technology Based On DDS

With the continuous development of telecommunications, frequency-hopping is increasingly applied to military and civilian areas, since it can provide robustness to interference, efficiency in utilizing frequency spectrum and superb privacy. The frequency mixer is the core unit of the frequency-hopping system, which determines the performance of the whole system.This article investigates direct digital synthesis (DDS) and phase lock loop (PPL), further on, selected direct simulating PLL by DSS output as approach to realize the frequency mixer. Controlled by TMS320LF2407, DDS chip AD9858 generated 11 sine waves of different frequencies among 100-110MHz. Taking the output signal of DDS as the reference signal of PLL chip STW81102, the system finally outputs a frequency-hopping signal among 3-3.5GHz. Feasibility of the scheme is testified by means of experiment.