基于晶体振荡器的MIT系统激励源设计及其实现  

Design and implementation of excitation source based on crystal oscillator for magnetic induction tomography system

作　　者：吕华[1] 秦明新[1] 李世俊[1] 王聪[1] 

机构地区：[1]第四军医大学生物医学工程系电子学教研室,陕西西安710033

出　　处：《第四军医大学学报》2005年第10期944-947,共4页Journal of the Fourth Military Medical University

基　　金：全军医药卫生科研基金课题(01Z078)

摘　　要：目的: 设计一种应用于磁感应断层成像技术(mag neticinductiontomography,MIT)系统的10MHz高性能激励源,以提高MIT系统的测量精度. 方法: 根据高频电子电路设计原理及其电磁屏蔽技术,选用高频率精度和稳定性的恒温晶体振荡器,设计和实现了高性能激励源.结果: 激励源稳定输出10MHz正弦信号,频率稳定度优于1×10-7水平,杂波抑制和谐波抑制分别达到90dBc和45dBc,负载时输出电压峰峰值为12V,最大输出功率为1 3W. 结论: 设计的激励源提供了高频率稳定性和高信噪比的激励信号,为高精度的MIT测量奠定了基础.AIM: To improve the measurement precision of magnetic induction tomography (MIT) system by designing a high-performance excitation source.METHODS: On the basis of the principle of the high frequency circuit design and the techniques of electromagnetic shield,an excitation source was designed and implemented by a crystal with high frequency precision and stability.RESULTS: The excitation source output 10 MHz sine wave,with the stability of frequency of 1x10 -7,the cluster suppression of 90 dBc,the harmonics suppression of 45 dBc,the maximum amplitude of 12 V and the maximum output power of 1.3 W.CONCLUSION: Our designed excitation source provides a signal with a higher frequency stability and a higher SNR.The performance of the system lays the basis for high-precision MIT measurement.

关 键 词：磁感应断层成像 晶体振荡器 频率稳定性 激励源 

分 类 号：R318.3[医药卫生—生物医学工程]