Monolithic Gallium Arsenide Receiver for NMR Microscopy

9319399 Peck， T.本研究的目的是通过在单个单片GaAs衬底上制造射频（RF）检测线圈和前置放大器来提高核磁共振（NMR）显微镜系统的性能。这种电路元件的组合可以设计为提供最佳的信噪比（SNR）。射频微线圈将在平面几何结构中由4-7圈金导体形成。一个简单的调谐和阻抗匹配网络将射频线圈连接到一个单级，通用源配置，GaAs金属半导体场效应晶体管（MESFET）。放大器将被设计为高增益和低噪声在相对较窄的带宽（300+/- 0.1赫兹）所需的核磁共振信号检测。砷化镓MESFET放大器是实现这一目的的理想选择。该项目特别侧重于核磁共振显微镜原型集成电路的制造和测试。目标是建立这种方法的可行性，作为刺激更先进的核磁共振研究集成电路的未来发展。核磁共振显微镜（微线圈阵列、扫描核磁共振显微镜和超导射频线圈）的未来发展将依赖于核磁共振集成电路技术的进步。这项提案汇集了一个由核磁共振、射频和制造专家组成的团队，他们正在合作开发新技术。该项目的成功预计将对核磁共振显微镜产生重大影响，特别是对整个核磁共振光谱和成像领域具有潜在的优势。＊＊＊

9319399 Peck, T. The objective of this research is to improve the performance of nuclear magnetic resonance (NMR) microscopy systems by fabricating the radio-frequency (RF) detection coil and preamplifier on a single monolithic GaAs substrate. This combination of circuit elements can be designed to provide an optimum signal-to-noise ratio (SNR). The RF microcoil will be formed from 4-7 turns of a gold conductor in a planar geometry. A simple tuning and impedance matching network will link the RF coil to a single stage, common source configuration, GaAs metal semiconductor field effect transistor (MESFET). The amplifier will be designed for high gain and low noise over the relatively narrow bandwidth (300+/- 0.1 NHz) needed for NMR signal detection. Gallium arsenide MESFET amplifiers are ideal for this purpose. This project focuses specifically on the fabrication and testing of a prototype integrated circuit for NMR microscopy. The goal is to establish the feasibility of this approach as a stimulus to the future development of more advanced integrated circuitry for NMR research. Future developments in NMR microscopy (microcoil arrays, scanning NMR microscopes, and superconducting RF coils) will rely on advances in NMR integrated circuit technology. This proposal effort assembles a team of NMR, RF, and fabrication experts who are collaborating to develop the new technology. The success of this project is expected to have a major impact on NMR microscopy in particular, with potential advantages for the entire field of NMR spectroscopy and imaging. ***