Research On Micro-sensing Circuit Based On Planar Microstrip Antenna And Its Application In Oil Detection

The quality of the oil in the aviation system is critical for the normal operation of the instrumentation.The existing oil monitoring system mainly adopts the offline methods,with a long time period and lagging test results.With the development of microstrip antenna technology in recent years,it has shown great advantages in the miniaturization of the sensing circuit.Compared with traditional antennas,microstrip antennas have the advantages of small size and easy for mass production with PCB manufacturing technology.Aiming at the actual engineering needs of field measurement of oil aging,this paper proposes a micro-sensor based on impedance detection to quickly detect the permittivity of the oil.Microstrip antenna-based microsensors are designed in the shape of interdigitated electrodes and manufactured using MEMS technology.Together with the impedance analysis circuit based on the AD5933 chip,the real and imaginary parts of the complex impedance of the oil can be measured.The core circuit board based on STM32 communicates with the host computer software in the computer and displays the measurement results in real time from the front panel of the host software.Lab VIEW is selected as the host computer software.When the water content in the oil changes,the sensor can detect the impedance information of the oil,and the host computer software can calculate the age of the oil in real time.At the end of the article,experiments are designed to verify the function and performance of the system.The experimental results show that the designed oil aging detection system based on microsensor and impedance test has the advantages of small size,high sensitivity,high accuracy and good repeatability,which verifies the effectiveness of the system design.