  To satisfy the long-range and energy self-sustaining communication needs of
electronic devices in the Internet of Things (IoT), we introduce a simultaneous
wireless information and power transfer (SWIPT) system using the resonant beam
that incorporates a telescope modulator inside a cavity for suppressing
diffraction losses. We theoretically analyze power transfer in the resonant
beam system with telescope internal modulator (TIM-RBS) considering the
electromagnetic field propagation, the end-to-end (E2E) power transfer, and
power and information reception. The numerical evaluation demonstrates that the
TIM can effectively compress the beam spot, which allows the TIM-RBS to
transmit energy twice as far as the RBS without TIM at higher power.
Additionally, the largest transmission distance and maximum output power are
proportional to the input power, and about 34m transmission distance, 4W
electric power, and 12bps/Hz spectral efficiency can be achieved in the TIM-RBS
with 200W input power. Hence, TIM-RBS can be considered as a promising option
for realizing long-range, high-power, and high-rate SWIPT.
