微尺度高功率核磁射频功率合成器研究

Micro – scale High Power RF MRI power combiner design

核磁共振工作频率在百兆赫兹频率左右,利用常规四分之一波长实现无源合成器尺寸较大,承受功率较低,分析了高功率下无源合成器的微尺度技术,利用无源微尺度技术设计了小型化高功率合成器,在大功率工作状态下,该器件输入输出回波损耗在-30dB,插入损耗小于0.3dB。在核磁共振3.0T频段下,实现功率等级为12KW峰值功率,平均功率为1.2KW,尺寸比四分之一波长缩小10倍,可以满足核磁共振系统3.0T射频大功率放大器无源合成需求。

MRI（magnet resonance imaging） system RFPA（Radio Frequency Power Amplifier） working frequency is about 100MHz, and the Combiner withλ/4 line size is large and support power is about 100Watte. So big size and lower power is big issue. This paper present the combiner micro-scale technical under the high power condition, and get the micro-scale higher RF combin-er with integration technical, and the return loss is＆lt;-30dB, insert loss is＆lt;0.3dB. This combiner working frequency is 3.0T MRI sys-tem frequency band（128MHz）, and could support 12KW peak power and average power 1.2KW, and size reduce 10 times, it could meet the 3.0T MRI RFPA combiner requirements.