Design of a Simultaneous Information and Power Transfer System Based on a Modulating Feature of Magnetron

According to the nonlinear response characteristics of magnetron, this article proves that a 2.45 GHz band continuous-wave magnetron can perform as a modulator in communication system. The intermediate frequency (IF) signal coupled to the power supply of magnetron, as the ripple of anode voltage, can be modulated to a nearby band centered on the resonant frequency of magnetron. We deduced the output expression of free oscillating magnetron under the influence of anode voltage ripple. And electromagnetic simulation was accomplished to testify the validity of the theoretical derivation. Moreover, we designed the circuit to couple signal with frequencies of 2, 3, and 4 MHz to the anode voltage. The output spectrum of magnetron changed as the frequencies were tuned, to satisfy the frequency requirements for modulating. Finally, a simultaneous information and power transfer system based on a magnetron combined with the power supply coupling circuit was developed and tested. This system achieved the modulation, amplification, transmission, and demodulation of low-frequency signal which is equivalent to human voice. This research reveals that the proposed techniques have great potential for future simultaneous wireless information and power transfer (SWIPT) system because they provide higher power at lower cost.