An improved RF circuit for Overhauser magnetometer excitation

作者：Zheng Di; Zhang Shuang^*; Guo Xin; Fu Haoyang

来源：Conference on Radiation Detectors - Systems and Applications XVI, 2015-08-12 To 2015-08-12.

DOI：10.1117/12.2187183

• Overhauser magnetometer
• proton magnetometer
• dynamic nuclear polarization (DNP)
• RF polarization
• quartz crystal oscillator
• RF power amplifier
• harmonic suppression
• high sensitive field observation

Overhauser magnetometer is a high-precision device for magnetostatic field measurement, which can be used in a wide variety of purposes: UXO detection, pipeline mapping and other engineering and environmental applications. Traditional proton magnetometer adopts DC polarization, suffering from low polarization efficiency, high power consumption and low signal noise ratio (SNR). Compared with the traditional proton magnetometer, nitroxide free radicals are used for dynamic nuclear polarization (DNP) to enhance nuclear magnetic resonance (NMR). RF excitation is very important for electron resonance in nitrogen oxygen free radical solution, and it is primarily significant for the obtention of high SNR signal and high sensitive field observation. Therefore, RF excitation source plays a crucial role in the development of Overhauser magnetometer.
In this paper, an improved design of a RF circuit is discussed. The new RF excitation circuit consists of two parts: Quartz crystal oscillator circuit and RF power amplifier circuit. Simulation and optimization designs for power amplifier circuit based on software ADS are presented. Finally we achieve a continuous and stable sine wave of 60MHz with 1-2.5 W output power, and the second harmonic suppression is close to -20dBc. The improved RF circuit has many merits such as small size, low-power consumption and high efficiency, and it can be applied to Overhauser magnetometer to obtain high sensitive field observation.

• 出版日期2015
• 单位吉林大学