精密相位控制的多通道任意波形发生器设计

Design of Multi-channel Arbitrary Waveform Generator with Precision Phase Control

为了满足对多路波形及其相位进行控制的要求,设计了一种通道可拓展且具有高精密相位控制的多通道任意波形发生器。基于直接数字频率合成技术,由现场可编程门阵列实现多通道任意波形的产生。采用高速模数转换芯片对各通道输出波形同步采样。由ARM微处理器对采样数据进行离散傅里叶变换处理得到相位差,并根据差值对输出相位控制字进行比例-积分-微分调节,实现了相位的闭环实时补偿。多个系统可通过同步时钟接口并行工作,实现输出通道的扩展。试验结果表明:该系统相位精度为±0.02~°,正弦波和方波的频率范围为1μHz^10 MHz,输出幅度范围为±10 V,能够实现多系统并行输出。

Multi-channel arbitrary waveform generator with extensible channel and high precision phase control was designed in order to meet the requirements of multi-channel waveform and phase. Based on the direct digital frequency synthesis technology,multi-channel arbitrary waveform was generated by field-programmable gate array. The output waveforms of each channel was synchronously sampled through high-speed analog to digital acquisition chip. The phase difference was obtained by using advance risc machines( ARM) to deal with sampling data with the method of discrete Fourier transform. The output phase control word was adjusted with proportional-integral-differential regulator according to the difference,to realize closed-loop and real-time phase compensation. Multiple systems could work in parallel through synchronous clock interface to realize the expansion of output channels. Experimental results show that the phase accuracy of this system reaches± 0. 02°. The range of sine and square waveforms frequency is 1 μHz ~ 10 MHz. Output amplitude range is± 10 V. Multi-system parallel output is obtained.