Research On Simultaneous Wireless Information And Power Transfer Based On Magnetic Resonance

The simultaneous wireless information and power transfer(SWIPT)technology is a combination of wireless power transmission and wireless communication.Because information and energy can be transmitted synchronously,the transmitting end and the receiving end do not need independent energy transceiving and signal modulation/demodulation equipment,therefore the device complexity is greatly reduced.In this paper,the human implanted organ is used as the application scenario to study the principle,scheme design and rate-energy boundary(R-P boundary)of SWIPT technology.Finally,a physical system is built for verification.Firstly,this paper studies the advantages and disadvantages of the three technical solutions for wireless energy transfer and determines the magnetic resonance type as the wireless energy transfer scheme.Then,the coupled-mode theory is used to study the basic requirements of magnetic resonant wireless power transfer and the principle of frequency splitting is explained.Secondly,the voltage,current and power gain of the four wireless power transmission circuit structures of series-series(SS),series-parallel(SP),parallel-series(PS),and parallel-parallel(PP)are analyzed through the mutual inductance theory.Finally,the SP structure was selected as the circuit structure of the wireless energy transfer,and the specific circuit parameters were determined.Thirdly,combined with the frequency splitting of wireless energy transmission,2FSK is determined as the modulation scheme of communication,and a SWIPT model based on 2FSK is proposed.Then the expressions of the received energy and channel capacity are derived separately for this model.On this basis,the SWIPT is realized through power allocation,and the boundary between energy and information is obtained,which provides the theoretical maximum boundary for the system design.Finally,based on the circuit structure and the derived circuit parameters obtained by simulation,the actual system is built.For the wireless energy transfer,the experiment is performed in the resonant state and the non-resonant state.The experimental data is compared with the simulation results and the correctness of the analysis and simulation for wireless energy transfer theory is verified.For wireless communication,the channel capacity and bit error rate are obtained experimentally.Finally,the energy rate point of the actual system is within the limits of the R-P boundary,which verifies the correctness of the R-P boundary derivation process.