Design Of AOTF Drive Circuit And Dual Ultrasound Transducer Matching Circuit

Spectral imaging technology is to study the target material of the image and spectral information collected in different wavelengths,and according to its spectral characteristics of the target substance is detected and analyzed,spectral imaging is widely used in remote sensing,deeply space exploration and other fields.With the development of spectral imaging technology,its spectral measurement range,spectral resolution,image clarity and other requirements are getting higher and higher.The Acousto-Optic Tunable Filter(AOTF),which is currently using the fourth generation of spectroscopic technology,is widely used in imaging systems,AOTF has a decisive influence on the performance of the spectral imaging system,such as the operating wavelength range,the spectral diffraction efficiency and the resolution of the spectroscopic device as a spectral imaging system.Therefore,it is certain practical significance to study how to improve the performance of AOTF.The performance of AOTF is mainly affected by the AOTF drive circuit system and AOTF internal ultrasonic transducer structure and matching circuit.Thus,a high performance AOTF drive circuit and dual ultrasonic transducer matching circuit are designed in the paper.AOTF as a power-driven device,according to the requirements of its work and other requirements,designed a certain bandwidth and power output stability of the AOTF drive circuit,the output power in the 50 ~ 210 MHz bandwidth within the stability of 33 ~ 35 dBm,the AOTF drive circuit system is well suited to meet the AOTF work requirements.Ultrasonic transducers are important components of AOTF.As the ultrasonic transducer has different input impedance at different frequencies,when the output impedance of the AOTF drive circuit and the ultrasonic transducer input impedance mismatch will produce energy loss,resulting in the drive power can not be the maximum transfer to the ultrasonictransducer,So that the AOTF spectral diffraction efficiency is reduced,affecting the spectral image clarity.In this paper,a new type of matching circuit with wide bandwidth,high diffraction efficiency and power efficiency is designed by using filter network matching theory and RF circuit theory by studying the impedance frequency characteristics of ultrasonic transducer in depth.Experiments and optimization of AOTF drive circuit and the dual ultrasonic transducer matching circuit are carried out on the experimental test platform.Finally,the spectral efficiency of AOTF is up to 93.9%,the spectral bandwidth is less than 5nm,dual transducer matching circuit power efficiency is over 90%,which improved spectral diffraction efficiency and resolution in the 420 ~1150nm band.Finally,the imaging of the imaging system prototype was measured,target imaging quality has been significantly improved.