Magnetic Field Leakage Cancellation in Multiple-Input Multiple-Output Wireless Power Transfer Systems

This letter presents a method to cancel magnetic field leakage while maintaining high power transfer efficiency (PTE) in multiple-input multiple-output wireless power transfer systems. To achieve low leakage and high PTE, the problem of PTE maximization under the cancellation condition of the magnetic field leakage is solved, which is a maximization problem of affinely constrained Rayleigh quotients. Subsequently, the optimal amplitudes and phases of the input voltages at the transmitter array and the optimal load impedances at the receivers are shown. This method can further reduce the magnetic field leakage by up to 31 dB compared with the PTE maximization method, while having a PTE drop within 5.5%.

Automated summary

This letter presents a method to cancel magnetic field leakage while maintaining high power transfer efficiency (PTE) in multiple-input multiple-output wireless power transfer systems. The method solves the maximization problem of PTE under the cancellation condition of magnetic field leakage and provides optimal solutions for input voltages and load impedances. The proposed method can significantly reduce magnetic field leakage by up to 31 dB with only a slight drop in PTE.