The limit of this method is that the sinewavegenerator with high performance is necessary, especially the stability, the noise and distortion of generator.
其局限性则是对交流信号源要求较高，要求高稳定性、低噪声及低失真度；
2
The system adopts direct digital synthetic (DDS) technology for building the sinewavegenerator to realize continuous regulation of amplitude, frequency and phase modulation.
系统采用直接数字合成（DDS）技术构建正弦波发生器，实现幅值、频率、相位等连续调节；
3
Skills: 1, a solid basic skills specialized courses, conducted active sinewavegenerator, MF-47 multimeter, transistors FM wireless transmitter, and so the design and production;