Research On Self-powered Active RFID Tags Based On Micro Energy Harvesting

The Internet of Things(IoT)is the third revolution in the world's information technology industry.It uses the Internet to connect any object around the world.The objects can communicate with each other through the Internet.The traditional information collection technology has been changed a lot by the IoT.The IoT has penetrated deeply into all walks of life and brought great convenience to industrial production and social life.The collection of information on the IoT relies on millions of information sensing devices around the world,and today these sensors are still powered by batteries.Batteries have many shortcomings such as limited service life,high maintenance costs,and aggravated environmental pollution,so this is not the best solution for the energy supply of the IoT.With the development of science and technology,a self-powered system has been proposed,and its outstanding advantage is that it can supply equipment by collecting energy from the environment to achieve continuous equipment operation.RFID is an important sensory sensing device in the IoT technology,but traditional passive RFID tags use electromagnetic coupling to obtain working energy and therefore have the disadvantages of short communication distance and only passive identification.In order to overcome these shortcomings,in this thesis a self-powered active RFID tag system based on the mechanical energy harvesting technology was designed,which consist of the energy harvesting unit,power management unit,energy storage unit and radio frequency transceiver.In addition,after completing the verification platform,two typical application demonstrations were also performed.The main work of this thesis includes:(1)The structural characteristics of different working modes of the triboelectric nanogenerators and the electrical characteristics of the triboelectric nanogenerators are summarized,and the triboelectric nanogenerators equivalent circuit model is built.Then the theory of the optimum resistance load,capacitive load and charging characteristics and the optimum capacitive load of triboelectric nanogenerators is studied.(2)A high-performance triboelectric-electromagnetic hybrid nanogenerator was designed by introducing hybrid energy harvesting technology.Combined with its feature of powering wearable electronics,it is designed to be packaged into the human shoes,which can convert the mechanical energy of the human body during walking into electrical energy.(3)According to the electrical characteristics of the triboelectric nanogenerator with high voltage,low current,and high output impedance,a universal transistors-controlled triboelectric nanogenerator power management module(TC PMM)circuit was designed,and the transistors served as electronic switches to automatically change the connection types of transition capacitor array from series in charging state to parallel in discharging state.Experiments show that the TC PMM circuit can significantly improve the huge impedance mismatch between the triboelectric nanogenerator and energy storage capacitor.(4)Utilizing the triboelectric-electromagnetic hybrid nanogenerator,the TC PMM circuit,the LTC3588 ultra-low power voltage regulator circuit and other functional modules to complete the self-powered active RFID tag prototype and the establishment of verification platform,and then use the self-powered active RFID tag prototype and the verification platform to demonstrate two typical applications: remotely controlled automatic doors,single target and multi-target active identification,response and early warning.