Applied Research Of Data Acquisition And Transmission System Of LFMCW_THz Imaging Based On FPGA

Terahertz wave which is in the infrared and millimeter wave, and usually refers tothe frequency in the electromagnetic radiation whose frequency is between0.1THz-10THz, is a cutting-edge technology of current international attention.Terahertz wave has many characteristics, such as transient, coherence, transmission,absorption, safety and so on. Terahertz wave can be widely used in various fields, andthe combination of wide-band terahertz and linear frequency modulation continuouswave (LFMCW_THz) can achieve high range resolution and3D imaging, especiallywith the research and utilization of high value in nondestructive detecting and safetytesting. The key technology in the LFMCW_THz imaging and mature productdevelopment is not enough; therefore it is necessary to carry out the applicationresearch in the field.The building of the frequency modulated continuous wave imaging system wascompleted through the research of the generation and detection of terahertz. Thedouble frequency sources were used in the system to generating terahertz radiation andthe vibration signal by frequency doubling technology, and the signal detection and theintermediate frequency signal were completed by using the mixing, and the imagereconstruction was completed with the data which was got through the system of theacquisition and transmission. The dynamic range of system design and construction atleast50dB, range resolution is10mm, can complete two-dimensional andthree-dimensional imaging. The system can be used in the field of nondestructivedetecting, such as the hole, the plastic foam insulation material to complete the airportsecurity check, anthrax and other biochemical items detection in the safety detectionfield.The hardware design of data acquisition and transmission part, data acquisitionpart of the software design and test were completed from the further research about thedata acquisition and transmission of the system. The repetition frequency of1M signalsampling was achieved, and the overall debugging the system of the data acquisitionand transmission system was completed. The results show that the acquisition can wellmeet the system requirements of current sampling, sampling period adjustment canmeet the system after the upgrade of the sampling requirements; at the same time,acquisition and transmission system can be used in other systems, such as X-ray imaging system (industrial CT).In a word, a comprehensive, system, detailed analysis and exploration of thefrequency modulated continuous THz wave imaging system was given in the paper.The study about the data acquisition and transmission of the system was done, and theresearch results are important to the system of the frequency modulated continuousTHz wave imaging.