  Integrating the wireless power transfer (WPT) technology into the wireless
communication system has been important for operational cost saving and
power-hungry problem solving of electronic devices. In this paper, we propose a
resonant beam simultaneous wireless information and power transfer (RB-SWIPT)
system, which utilizes a gain medium and two retro-reflecting surfaces to
enhance and retro-reflect energy, and allows devices to recharge their
batteries and exchange information from the resonant beam wirelessly. To reveal
the SWIPT mechanism and evaluate the SWIPT performance, we establish an
analytical end-to-end (E2E) transmission model based on a modular approach and
the electromagnetic field propagation. Then, the intra-cavity power intensity
distribution, transmission loss, output power, and E2E efficiency can be
obtained. The numerical evaluation illustrates that the exemplary RB-SWIPT
system can provide about 4.20W electric power and 12.41bps/Hz spectral
efficiency, and shorter transmission distance or larger retro-reflecting
surface size can lead to higher E2E efficiency. The RB-SWIPT presents a new way
for high-power, long-range WPT, and high-rate communication.
