Design And Implementation Of Multi-channel Synchronous Arbitrary Waveform Synthesis Module For Quantum Control

In recent years,the control platforms for the implementation of quantum chip measurement and control in various scientific research institutions have the defects of large amount of commercial instruments,synchronization disorder,and functional redundancy.In order to improve the current quantum control environment and improve the efficiency of quantum chip test experiments,a special measurement and control instrument is urgently needed to replace the construction and control of traditional commercial instruments.How to synthesize the pulse excitation signal with high precision,high stability and high synchronization performance is the key to the realization of the instrument function.In this paper,a set of multi-channel high-synchronous arbitrary waveform synthesis module is designed for the requirement of quantum logic gate to be compiled into actual pulse waveform transmission during quantum chip measurement and control.A single module is implemented using the hardware architecture of "Vertex-7 FPGA+Kintex-7 FPGA+DAC".The two FPGAs are clearly defined.The Kintex-7 FPGA completes the DAC chip configuration,command and waveform data reception.The Vertex-7 FPGA implements waveform data storage and playback.The paper analyzes the principle of direct digital waveform synthesis and direct digital frequency synthesis technology and the reason that the output between the channels is not synchronized.For the characteristics of short pulse and complex waveform output signals,the direct digital waveform synthesis technology is used to realize the function of arbitrary waveform synthesis module.Based on the AD9739,a software and hardware synchronization scheme is designed.This design uses OSERDES in FPGA to achieve high-speed interface with AD9739.The module has 8 independent output channels,each of which implements 4 waveform sequence data storage by FPGA,which reduces the peripheral circuit design pressure.The control commands are received using the RS-422 protocol,and the waveform data is first downloaded from the Gigabit Ethernet to the Kintex-7 FPGA and then forwarded to the internal memory of the Virtex-7 FPGA via a custom communication interface between the two FPGAs.The output circuit of AD9739 is realized by two methods:balun and op amp.For the requirement of filter performance of pulse waveform,Bessel filter circuit is used to realize low-pass filtering.In addition,PCB design is critical to achieving synchronization,so the stack design and trace design are summarized and analyzed.After testing,the design can work at 2Gsps sampling rate and can better restore the waveform.When the response period trigger signal is played,there is no leakage or multicast phenomenon,the waveform curve is smooth,and there is no disorder or glitch.The pulse signal pulse width and carrier frequency are within the allowable error range of the set value,and the inter-channel synchronization delay is less than 100ps.