Direct digital synthesis based - function generator with digital signal modulations

This paper focuses on signal generation with digital modulations, especially on the possibility of using the direct digital synthesis method. The specific structure of the function generator is explained. The developed construction is designed as a laboratory device. Realization enables to operate this device in two ways, via the user interface in the PC through the USB bus or by the display and keypad located directly on the product. Furthermore, this paper deals with results of measurement digital modulation generating, signal distortion and the test measurement in frequency and time domain.