The Study About A Controlling Method Of Rfid Communication Distance

Currently, because of the lower power consumption and less transmission power of RFID, while there is few study on controlling of RFID communication distance. In this paper, a new technology-RFID communication distance control was proposed according to the requirement of RFID in financial transactions.In the thesis the main experimental work are the actual measurement on external field-strength of antenna of gemalto viewer using oscillograph,then describe the change trends of field-strength in the chart and analyze that whether the communication distance of coil antenna could be controlled ; actual measurement on external field-strength of element antenna with 2.4GH, then describe the change trends of field-strength through RSSI detection and extract the threshold of communication distance scientifically. At last,measure the rate of successful communication using the threshold to provide basis for whether the communication distance of microwave element antenna could be controlled.The main Contents of study are as follows:(1)In theory, study the working principle and analyze the basic parameters. Analyze the development trend of label antenna from the aspect of RFID development.(2)Obtain the field-strength chart of gemalto viewer through experiments and analyze that whether the field-strength can control the communication distance.(3)Obtain the field-strength measurement of a 2.4G label and extract the threshold scientifically. At last, measure the success rate of credit card according to the threshold, and test that whether the communication distance could be controlled through the threshold.(4)Add the metal detection function to test whether the label is around the viewer , and avoiding the far distance communication of label when the transmission power was increased.In this paper, field-strength can be judged then to control the communication distance precisely before establishing communication through the combination of field-strength detection and metal detection,in theory and experiment test. It can provide some reference for communication reliability and security and can promote the development of RFID.