一种USB接口功率任意波发生器设计

为了缩短井下短距离无线传输发射机的研发时间，没有采用常规的使用商用任意波发生器的技术路线。专门设计了一种功率任意波发生器，上位机通过USB接口下载波形数据文件，信号发生器可以输出高达6W的信号。为了实现该设计，使用专用USB-SPI桥接芯片完成上位机与高集成度模拟前端芯片的USB接口通讯。由于上位机的非实时操作系统不能产生稳定、高速的指令发送，使用同步FIFO来存储并回放SPI总线上的信号，解决了SPI通讯速率的匹配问题，增强了输出更新频率的稳定性。该功率任意波发生器可以输出6W、10位精度，500 kSa/s采样频率的任意波形，具有512 k采样深度，满足井下SDR发射机设计需求。其模拟前端电路与井下发射机完全相同，实现了一次性硬件开发验证，缩短了研发时间。

Design of a power arbitrary wave generator with USB interface

In order to shorten the development time of downhole short-distance wireless transmitter, the conventional technical route using commercial arbitrary wave generator is not adopted. A power arbitrary wave generator is specially designed. The host computer downloads waveform data files through USB interface. The signal generator can output up to 6W signal. In order to realize this design, a special-purpose USB-SPI bridge chip is used to complete the communication between host computer and the highly integrated analog front-end (AFE) chip via USB interface. Because the non-real-time operating system of the host computer can not produce stable and high-speed command transmission, the synchronous FIFO is used to store and play back the signals on the SPI bus, which solves the problem of matching the SPI communication rate and enhances the stability of the output update frequency of signal. This power arbitrary wave generator can geneartes 6W, 10-bit, 500 kSa/s arbitrary waveforms with 512 k samples deep memory meeting the design requirements of downhole SDR transmitter. Its analog front-end circuit is exactly the same as the underground transmitter, which realizes one-time hardware development and verification, and shortens the development time.