.1.5 Gsps High-speed Data Acquisition System Design

With the development of electronic industry, high-speed data acquisition is widely used, especially in the applications such as software radio, digital oscilloscope and aperture radar, which all need to solve the problems of acquisition and processing of signals with wide bandwidth. It means that higher requirements are presented of the data acquisition system: higher sampling speed and resolution, larger bandwidth and storage capacity.At present, with the development of the ADC's structure design and semiconductor technology, the performance of ADC devices is improved quickly. There are 3 kinds of framework scheme of ADCs mainly, which can achieve high sampling speed. They are single-chip and single-channel ADCs, single-chip and multi-channel ADCs, several pieces of single-channel, or multi-channel ADCs. Suitable solution can be selected according to the different requirements.But the transmission and storage of the sampled data are limited by the speed of other signal processing devices, which used in the back-end of the system. Therefore, it is necessary to choose an appropriate structure to build a high-speed data acquisition system. Generally, the storage and processing module is constructed by FPGA or DSP or both of them.An ADC+FPGA+DSP's framework is used in this project to implement the task that signals can sampled with the speed of 1.5GHz/s and the sampled data can be stored and processed. A high speed single-chip and single-channel ADC-AT84AS003 of E2V is used in the front of the system, and a FPGA + DSP's framework is used in the storage and processing module in the back-end of the system. FPGA can be used to implement some pretreatment algorithm of signals with large amount data. DSP can be used to implement various and complex digital signal processing algorithm. This framework structure is versatille, flexible for modular design, and can be used in real-time data acquisition and processing.The design of ADC module and data storage module are emphasized in this paper, which are the critical parts of high speed data acquisition system. PCB layout, signal integrity and power design are also introduced in this paper.