中文摘要：

在自主研制的动态核极化（Dynamic Nuclear Polarization,DNP）分子影像装置的基础上，提出了一种集DNP和电子顺磁共振（Electron Paramagnetic Resonance,EPR）于一体的多功能谱仪，并对其中的关键部件之一——微波桥进行了设计．微波桥的引入，实现了DNP微波发射机的集成化，以及在DNP谱仪基础上的EPR功能扩展．通过结构设计、电路仿真及系统测试，完成了高频谱纯度、高动态范围的微波发射机以及低噪声系数的微波检测系统的设计与制作．并通过DNP增强实验以及连续波EPR实验对微波桥的性能进行了验证．

英文摘要：

A multi-functional spectrometer,capable of dynamic nuclear polarization(DNP)and electron paramagneticresonance(EPR)experiments,is put forward on the basis of a home-built DNP-magnetic resonance imaging(MRI)spectrometer.A key component of the multi-functional spectrometer,microwave bridge,was designed and implemented.The microwave bridge was used to integrate the microwave transmitter of the DNP spectrometer and to enable the EPRcapability.A transmitter system with high spectrum purity and dynamic range as well as a detector with low noise figurewere also implemented by structure designing,circuit simulation and system evaluation.DNP and continuous wave EPRexperiments were conducted to verify the reliability of the microwave bridge.