波谱学杂志 ›› 2022, Vol. 39 ›› Issue (2): 163-173.doi: 10.11938/cjmr20212958

• 研究论文 • 上一篇    下一篇

一种无磁化的5 T磁共振射频功率放大器设计

骆俊1,2,刘盛平1,杨兴2,王佳升1,2,李烨2,*()   

  1. 1. 重庆理工大学 药学与生物工程学院, 重庆 400054
    2. 广东省磁共振与多模态成像重点实验室, 劳特伯生物医学成像研究中心(中国科学院深圳先进技术研究院), 广东 深圳 518055
  • 收稿日期:2021-11-23 出版日期:2022-06-05 发布日期:2021-12-27
  • 通讯作者: 李烨 E-mail:liye1@siat.ac.cn
  • 基金资助:
    中国科学院战略性先导科技专项(B类XDB25000000);国家重点研发计划项目(2021YFE0204400);深圳市优秀科技创新人才培养项目(RCYX20200714114735123)

Design of a 5 T Non-magnetic Magnetic Resonance Radio Frequency Power Amplifier

Jun LUO1,2,Sheng-ping LIU1,Xing YANG2,Jia-sheng WANG1,2,Ye LI2,*()   

  1. 1. College of Pharmacy and Bioengineering of Chongqing University of Technology, Chongqing 400054, China
    2. Key Laboratory for Magnetic Resonance and Multimodality Imaging of Guangdong Province, Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
  • Received:2021-11-23 Online:2022-06-05 Published:2021-12-27
  • Contact: Ye LI E-mail:liye1@siat.ac.cn

摘要:

本文介绍了一种可以不接环形器,并在扫描间使用的5 T磁共振射频功率放大器(RFPA).该RFPA基于驻波高耐受的横向扩散金属氧化物半导体(LDMOS)功率管进行设计,共包含三级放大电路.针对传统磁共振RFPA中带磁芯的传输线变压器进行了无磁化的设计,加强了对反射功率的监控,采用模拟负反馈技术实现了对RFPA非线性的自动矫正.测试结果显示该RFPA的输出功率为2 kW,在负载扰动(反射系数Г < 0.5)时,40 dB动态输入范围,其增益线性度≤ 1 dB,相位线性度≤ 10˚,满足成像需求,验证了该设计方案的合理性与可行性.

关键词: 磁共振成像(MRI), 功率放大器, 无磁, 负反馈

Abstract:

This paper introduces the design and implementation of a 5 T magnetic resonance radio frequency power amplifier (RFPA), which can be used in scan rooms without a circulator. The RFPA was designed based on laterally-diffused metal-oxide semiconductor (LDMOS) power tube with high standing wave tolerance, and it contained a three-stage amplifier circuit. The transmission line transformers with magnetic core in RFPA was designed as non-magnetic. The reflected power was monitored tensely. The nonlinear automatic correction of RFPA was realized by using analogic negative feedback technology. The results showed that the output of RFPA power is up to 2 kW, the gain linearity performance is less than or equal to 1 dB, and the phase linearity performance is less than or equal to 10 deg over 40 dB range up to rated power during the load disturbance (reflection coefficient Г < 0.5), which meets the imaging requirements. Thus the rationality and feasibility of the proposed design scheme are verified.

Key words: magnetic resonance imaging (MRI), power amplifier, non-magnetic, negative feedback

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