Fpga-based Digital Synthesis Signal Generator

The DDS(Direct Digital Frequency Synthesis) technique adopts full-digital synthesismethods. The generated signals have advantages of high frequency resolutions, fastfrequency switching, continuous phase while frequency switching, low noise phase andbeing able to generate arbitrary waveforms.The thesis analyses the principle of DDS and the performance of output signals. An arbitrary waveforms generatorwhich can generate the triangle waveform, sawtooth waveform, FM, PM, AM, burstwaveform and other waveforms is designed with FPGA. Arbitrary waveforms can bedownloaded to the arbitrary waveforms generator via serial port of PC. The structure thatcombines a phase accumulator with frequency word calculation unit is used to design thefrequency modulation circuit. This structure can not only realize broad band linearfrequency modulation, but also nonlinear frequency modulation. The design and debuggingof the hardware and the software are finished.