Research On The Linearization Of Giant Magnetoresistance Sensor And Its Application

In recent years,with the development of the Internet of Things(IOT),as detecting element of IOT,sensor has a great demand.Magnetic sensor based on the giant magnetoresistance(GMR)effect,due to the small size,high sensitivity,easy integration,has becom priority choice for detecting magnetic field,current,movement,etc.According to the application's great requirment to linearized GMR sensor,firstly,introduces the typical structure of GMR sensor which has stable performance,about it's principle,characteristics and preparation,by analysis the influence of sputtering pressure and film thickness to film structure,roughness and magnetoresistance,cofirm the preparation conditions and films thickness of spin valve's structure to get stable magnetoresistance.Secondly,the research on GMR sensor linearization is carry out,based on implementation mechanism of linear GMR sensor,do research on magnetoresistance under different thickness of detecting film and different exchange bias field with regard to orthogonal type of bottom and top spin valves,double exchange biased spin valve,it is find that GMR sensor's linearity range can be tunned by different free film thickness and exchange bias field,on the baise of above research,we use three step lithography process and film deposition technology to fabricate the four end of wheatstone bridge type GMR sensor,and use micro detection platform to test the sample's property,the linear range is ? 10 Oe,and the sensitivity is 0.716mv/Oe.Finally,based on the characteristic parameters of linearized GMR sensor,studied its application in parking detection system,when vehicle stop,the geomagnetic field signal changed,by detecting the change can be used to judge the occupancy of parking spaces.This detection method has the advantages of small size,suit complex weather conditions,low cost and so on.Have important meaning to intelligent transportation system.