| Terahertz（THz）is a frequency band between microwave and infrared electromagnetic waves,which has important scientific significance and application prospect.With its unique performance advantages,terahertz（THZ）has been widely used in many fields.As one of the important terahertz devices,terahertz detector has always been the focus of research,but the traditional way designed by terahertz detector has low response,high noise,long response time,and not easy to achieve a compact array size,resulting in low imaging efficiency.The development of terahertz detector based on low cost and high integration CMOS technology is an important way to solve the above problems.In order to solve the problems of low response and low detection efficiency of traditional terahertz detectors,a high response detector array based on 0.18μm CMOS technology is designed in this paper.The research focuses on broadband antenna,high coupling degree self-mixing power detection circuit and integrated voltage amplifier on high gain plate.In order to achieve high responsiveness and short response time,an optimized line array of self-mixing power detector is proposed.Meanwhile,the crosstalk problem between detector pixels is explored and an optimization scheme is proposed.According to the test results,the designed detector has high responsiveness and can identify objects of different materials through transmission experiment.The specific research work of this paper is as follows:（1）Aiming at the problem of narrow band width and low gain of antenna on CMOS chip,curved and rectangular slots are opened on the antenna radiation surface to widen the bandwidth of antenna on CMOS chip.Simulation results show that the bandwidth range of-10 d B is 0.25THz～0.34 THz.In addition,the inner loop arc suspension of the antenna radiating surface is designed as the guide to gather the beam and improve the antenna directivity.The simulation gain for a single antenna is 3.9 d Bc.（2）The working principle of self-mixing power detection based on CMOS process field effect transistor is analyzed.An improved source-difference-driven self-mixing power detection circuit structure is proposed.By using cross-coupling capacitors,terahertz differential signals are coupled to the grid and source poles of the field effect tube,and the strength of the self-mixing terahertz signals in the field effect tube channel is enhanced to improve the responsiveness.In addition,combined with the integrated voltage amplifier to amplify the response signal after mixing,the detector can achieve high responsiveness.The test results show that the maximum response of detector line array under the radiation of 0.3 THz signal is 43.8 k V/W,and the corresponding minimum noise equivalent power is 20.5 p W/Hz1/2.（3）The design method of detector array is studied,the cause of crosstalk of detector array is analyzed,and the corresponding solution strategy is proposed.The layout design of 1×3detector line array and the flow plate are completed.The binding board,test board and peripheral components of detector array were designed,and the test environment was built to complete the static test and dynamic test of detector chip.In general,through the analysis of the terahertz detection theory,the research,design and test of the terahertz detector line array are completed,and the basic function of the terahertz detector line array is realized,which effectively improves the response of the Terahertz detector and improves the detection efficiency of the detector.The test results show that this work achieves the expected design effect. |
