Fe3O4/PDMS复合材料磁电容微弱信号检测电路的设计

针对Fe3O4/PDMS复合材料磁电容信号变化微弱，检测困难的问题，本文设计了一种基于充放电法的微小电容检测电路。文中详细论述了组成该电路的脉冲激励模块、C-V转换模块、信号调理模块及载波调解模块的原理及功能，同时搭建硬件平台对复合材料磁电容进行实验验证。通过对Fe3O4/PDMS纳米复合材料磁电容平行板结构进行测试实验，结果表明：在pf级范围内进行测试，检测电路的输出线性度较好，电路的标度因数与理论值相差较小。测试电路具有响应快速、外部电路简单、易于集成、稳定好、成本低等优点，具有较好的应用价值。

Design of weak signal detection circuit for magnetic capacitance of Fe3O4/PDMS composite material

In view of the problem that it is weak to change and difficult to detect the magnetic capacitance signal of Fe3O4/PDMS Composites. This paper designed a micro capacitance detection circuit based on the charging and discharging method. The circuit is composed of a pulse excitation module, a C-V conversion modulea, signal conditioning module and carrier mediated module. This paper discusses the hardware design of the circuit in detail and experimental verification. The results show: In the range of pf , the output linearity of the detection circuit is good, it is smaller difference between circuit scale factor and the theoretical value .The test circuit has the advantages of fast response, simple external circuit, easy integration, good stability and low cost, and has good application value.