The Study Of Phase-Demodulation Range-finding Techniques Based On SPAD

With the development of science and technology, the three-dimensional range-finding technology is put into more and more applications in our daily life, industry, military etc. All these applications can be divided into automation and non-automation. The applications of automation: pedestrian detection, volumetric rear vision for parking assistance, blind spot detection for safe lane change, lane departure warning and adaptive cruise control. The applications of non-automation: virtual human-computer interfaces providing immersive experience in gaming devices as well as in computer-aided design software, etc. However, the key technique of these applications is involved in distance measurement. In conclusion, it plays an important role in how to improve the efficiency and accuracy of distance measurement for further development of 3D applications. Therefore, it has great significance on the research of optical range-finding.In this work, the range-finding chip is designed by using of single photon avalanche diodes(SPAD) devices and the phase-demodulation range- finding techniques, and it is fabricated in 0.18-?m CMOS process.The main study of this paper is the phase-demodulation range-finding technique. With the intention of adapting to the requirement of low power consumption and portable for electronic products, our research of the three-dimensional range- finding will be done as following several aspects.Firstly, the existing 3D TOF range- finding is illustrated and the method of the SPAD phase-demodulation range- finding is chosen by comparing those methods with their advantages and disadvantages. We focus on explaining the principle of this technique. What's more, the error-analysis in this system is discussed.Secondly, it introduces the development of SPAD devices and shows the key techniques for SPAD design. Several SPAD structures are designed by compared those SPAD with performance in the deep sub- micron CMOS process. Then the SPAD layout is completed based on 0.18-?m standard CMOS process.Thirdly, it focuses on the discussion of the quenching and recharging circuits after the completion of the SPAD device. O n the one hand, the theory analysis for advantages and disadvantages of the existing quenching and recharge circuits is illuminated. And we propose a new circuit topology, which is referred to passive quenching and positive recharge circuit. On the other hand, the pixel circuit and layout is designed and the system on a chip of the phase demodulation range- finding is built by consisting of auxiliary circuits. Finally, the chip design is totally completed.