Samila A, Safronov I, Hotra O
Department of Radio Engineering and Information Security, Yuriy Fedkovych Chernivtsi National University, Kotsjubynskyi 2, 58012, Chernivtsi, Ukraine.
Department of Radio Engineering and Information Security, Yuriy Fedkovych Chernivtsi National University, Kotsjubynskyi 2, 58012, Chernivtsi, Ukraine.
Solid State Nucl Magn Reson. 2020 Dec;110:101700. doi: 10.1016/j.ssnmr.2020.101700. Epub 2020 Nov 12.
The paper describes development of the detailed structure and circuit diagrams of the continuous wave NQR temperature sensor with increased conversion linearity. It is experimentally established that at amplitude modulation of 40% and change of input voltage in the range of 20-1000 mV, the circuit of a symmetric marginal oscillator with a linear active demodulator provides better linearity of transfer characteristic than the circuits of asymmetric marginal oscillators with JFET or diode detectors. As a thermometric substance of the proposed NQR sensor, copper oxide CuO was used, which is characterized by a strong temperature dependence of the resonance frequency of Cu NQR. In contrast to Cl NQR in KClO, for cuprous oxide the temperature dependence of Сu NQR frequency in the frequency range 26.621-25.658 MHz is linear in the temperature range 100-390 K. It is experimentally confirmed that the use of a low mass sample (less than 200 mg) as a thermometric substance of the proposed NQR sensor is quite sufficient for successfully observation of the resonance line at the SNR equal to 9.1 dB.
本文描述了具有更高转换线性度的连续波NQR温度传感器的详细结构和电路图的研制情况。通过实验确定，在40%的幅度调制以及20 - 1000 mV的输入电压变化范围内，带有线性有源解调器的对称边缘振荡器电路比带有JFET或二极管探测器的非对称边缘振荡器电路具有更好的传输特性线性度。作为所提出的NQR传感器的测温物质，使用了氧化铜CuO，其特征在于Cu NQR的共振频率具有强烈的温度依赖性。与KClO中的Cl NQR不同，对于氧化亚铜，在26.621 - 25.658 MHz频率范围内，Cu NQR频率在100 - 390 K温度范围内呈线性关系。实验证实，将低质量样品（小于200 mg）用作所提出的NQR传感器的测温物质，足以在信噪比等于9.1 dB时成功观测到共振线。
