Design And Development Of Electrical Circuits For MEMS Based NIR Spectrometer

The rapid development of MEMS has greatly promoted the miniaturization and portability of NIR spectrometer in the recent years.However,the signal from the optical system is weak due to the characteristics of MEMS,and then performs of spectral resolution and reproducibility of absorbance are limited,the improvement of which requires more on noise suppression,acquisition speed,etc.To solve the problems mentioned above,electrical circuits are designed and developed to improve the performances of MEMS based NIR spectrometer,which have high SNR and can acquire light signal synchronously.Firstly,the background and significance of MEMS based NIR spectrometer is introduced.And domestic and overseas development of MEMS based NIR spectrometer and weak signal detecting technology is clarified,then the key points and difficult points of this topic are determined.In chapter 2,the whole scheme design of electrical circuits for MEMS based NIR spectrometer is proposed,and the working principle of MEMS based NIR spectrometer and requirements of system are described.Then key technologies of the scheme are illustrated,including signal amplifing,signal acquiring synchronously,data transferring by high-speed and controller selecting.After that,the software and hardware design is analysed in details.In chapter 3,according to characteristics of weak light signal,we design a low-noise and data acquiring circuit by means,including I-V converting,bandpass filtering,differential signal inputting and common-mode signal suppressing,magnetic coupling and optical coupling separating.Then the MEMS synchronous driving circuit is designed to drive the micromirror in a certain direction.Finally,we design and analyze power module and core-board module to ensure stability of the system.In chapter 4,we develop software modules of system based on FPGA and ARM.In order to ensure the efficient operation of the system,the software is developed according to the features of FPGA and ARM.Then the system can collect light signal synchronously and drive MEMS micromirror.And in the meanwhile,the data collected are transmitted to spectrum processor with high speed USB.Finally,the light signal acquiring module and MEMS driving module of electrical system for MEMS based NIR spectrometer are debugged and tested in this paper.And then,the overall debugging is taken and problems encountered in this experiment are analyzed and solved.The test results show that the system completely meets the requirements and achieves the desired purpose.The electrical circuits for MEMS based NIR spectrometer designed in this paper have higher SNR and functions of acquiring light signal with high speed,which have a very import significance and reference value for the development and popularization of MEMS based NIR spectrometer.