摘要：针对某微波探测载荷超声电机高精度扫描驱动控制的需求，采用直接数字合成(DDS)技术，由通用DDS集成芯片、数模转换器和比较器等构成信号源电路，设计出频率、占空比连续可调、相位连续变化并可分档设置的超声电机驱动PWM控制信号。实验结果表明，该信号源电路不仅可以有效地提高超声电机调频调速时的频率分辨率，而且可以增加超声电机的速度可控性，从而提高超声电机用于扫描驱动的转速控制精度和扫描周期稳定度。
关键词：超声电机；扫描驱动；DDS；信号源

Abstract: To the demand of microwave detection loading ultrasonic motor high precision scanning drive, signal source was introduced which was based on DDS. The circuit of signal source is composed of DDS integrated chip,DAC and comparators,etc. Frequency, duty cycle continuously adjustable phase continuous variation and subfile settings were achieved by ultrasonic motor drive PWM control signal. It is not only has high frequency resolution, but it also can increase the speed of the ultrasonic motor controllability. The results show that the drive speed accuracy and stability of ultrasonic motor scanning drive has been improved.
Key words: ultrasonic motor; scanning drive; DDS; signal source