磁通负反馈空心线圈传感器特性和噪声研究  

Research on characteristic and noise of magnetic flux negative feedback air coil sensor

作　　者：符磊[1,2] 林君[1,2] 王言章[1,2] 王世隆[1,2] 杨蒙蒙[2] 

机构地区：[1]地球信息探测仪器教育部重点实验室,长春130026 [2]吉林大学仪器科学与电气工程学院,长春130026

出　　处：《仪器仪表学报》2013年第6期1312-1318,共7页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(40904053);吉林省重大科技攻关项目(2012ZDGG003)资助

摘　　要：时间域空地电磁系统可以实现大深度探测,能够探测金属沉积矿床和地热储层,其接收装置常采用空心线圈传感器,传感器的匹配方式是输出端并联阻尼电阻,该电阻可以有效地抑制线圈的时域振荡,但是增加了传感器的噪声。研制了一种基于磁通负反馈机制的低噪声、大面积空地接收线圈传感器,通过理论分析给出了该方法的实现原理,建立了传统匹配方式和基于磁通负反馈方式的线圈等效模型,并深入分析了2种模型下传感器的幅频特性、带宽及影响空心线圈传感器信噪比的各噪声源,给出了2种方式下使传感器处于临界阻尼状态时系统噪声的仿真结果,将两者在相同带宽下的噪声有效值指标进行对比,证明了基于磁通负反馈方式的接收线圈能够达到与传统方式接收线圈一致的性能。噪声方面,在相同的线圈结构、温度不变(27℃)、频率范围为3 dB带宽的情况下,相比传统方式信噪比提高了10.6 dB。最后,采用小线圈传感器等效模型在野外进行了噪声测量,验证了理论的正确性。The time domain airborne-ground electromagnetic system is able to achieve great depth detection, and detect metal sedimentary deposit and geothermal reservoir; its receiving device usually uses air coil sensor. The sensor matc- hing mode is to connect a parallel damping resistance at the output end. The damping resistance can effectively restrain the coil time domain vibration ;however,it increases the noise of the sensor. This paper develops a low noise and large area airborne-ground receiving coil sensor based on magnetic flux negative feedback mechanism. Through theoretical analysis, this paper offers the implementation principle of this method;builds up the coil equivalent models based on traditional matching mode and magnetic flux negative feedback mode;and deeply analyzes the sensor amplitude-fre- quency characteristics,bandwidths and the noise sources that affect the signal to noise ratio of the air core coil sensor for the two models. Besides, the paper also gives the simulation results of system noise for the two models when the sen- sor is put in the critical damping condition, compares the noise RMS values of the two models under the same band- width;and proves that the receiving coil based on the magnetic flux negative feedback mode can achieve the same per- formance as the receiving coil based on traditional mode. For the noise, under the conditions of the same coil structure, constant temperature （27 ℃ ） and frequency range （3 dB bandwidth） ,the signal to noise ratio for magnetic flux nega- tive feedback mode is improved by 10.6 dB compared with that for the traditional mode. Finally, the small coil sensor equivalent model was used to carry out outdoor noise measurement ,which proves the correctness of the theory.

关 键 词：空心线圈传感器 磁通负反馈 频率特性 噪声分析 等效模型 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]