Design Of Sine Waveforms Generator With Adjustable Phase Difference

In production test and teaching experiment, sine waveforms generator is usedmore and more widely. Users want its performances higher and higher. Theamplitude and frequency are adjustable, what’s more, the determinate phasedifference between two signals is required. However, the sine waveforms generatorshaving those functions are expensive. Focus on this problem, this paper developed akind of cheaper sine waveforms generator with adjustable phase difference.FPGA developed rapidly in recent years. Integration is higher and frequency isfaster, but the price is lower than before. FPGA device supports online programmablefunction and has good scalability and portability. DDS is a kind of advanced digitalfrequency synthesis technology. It has a lot of advantages, such as high outputfrequency resolution, fast frequency conversion speed and so on.Based on the FPGA and DDS technologies, the design achieved the sinewaveforms generator, which has adjustable phase difference, by using STC89C52ascontrol center and combining basic operation circuit, modulation circuit and low passfilter. This design used the method of extraction component to generate sinewaveforms (That is extracting the sine waveforms component of lowest frequencyfrom square waveforms). Therefore, the phase difference adjustment between twosine waveforms was transformed into the phase difference adjustment between twosquare waveforms. The square waves were generated by the DDS system, which isbuilt on FPGA device. In addition, this design finished parameter settings by digitalencoder of20pulses/20locations. This method made parameter settings moreconvenient and simpler.The experiment proved that the system worked stably and could generate twoways sine waveforms, the sine waveform’s phase difference range from0°to359°.