The Applied Research Of WiTricity For Body Area Network

Body area network is a communication network composed by multiple sensor nodes.It has important application value in the medical treatment. It can collect important physiological parameters from body, then transmit data to outside and analysis process. As the sensor nodes have to be implanted or placed within the body area, they need to narrow the node cell volume and sacrifice the working life for the human body comfort. Traditional way of rely on energy saving and low power consumption to enhance the node working life have limitations.At this stage, with the body area network intelligence, miniaturization, high precision, real time, the improvement of body comfort needs and the extension of application field. The sensor nodes need to carry more and higher performance. This paper adopts magnetic resonance coupling wireless power transmission provide energy for body area network, Resonator placed in the sensor nodes compose wireless power transmission network.This article first introduced three kinds of wireless power transmission, research status and development trends, then expounded the basic principle of magnetic resonance coupling power transmission.Using the coupled mode theory, analyze magnetic coupling resonance system in theory, deduce the equation of motion from coupled systems, and analyze the power loss and coupling parameters who influence the power transmission from the equation of motion.Two kinds of resonator was made by high frequency simulation software. Chose different resonator size parameters to analyze the variation of the resonance frequency. Then analyzed the influence that resonator in different positions and relay resonator to wireless power transmission by the resonator electromagnetic field distribution. Made actual resonator and set up experimental circuit, observed the actual wireless power transmission effect, measured the voltage of load under different conditions, analyzed the influence of wireless power transmission when the resonator distance and position have changed.Finally, studied the law of multi-user wireless power transmission.Added multiple resonators in the simulation model, calculated the resonator magnetic field distribution in different position and distance. And simulated the magnetic field distribution of the small size resonator between different structure.Then combined experiment to measure multiple load voltage,analyzed the relay resonator influence on multi-user wireless energy transmission.