5G as a wireless power grid

TLDR

5G’s mm‑wave design delivers unprecedented radiated power densities, unintentionally creating a wireless power grid that could reach far beyond existing technologies but requires overcoming a fundamental trade‑off in wireless energy harvesting. The authors propose a solution that breaks the usual trade‑off between rectenna angular coverage and turn‑on sensitivity. Their approach uses a Rotman lens between antennas and rectifiers, combined with antenna sub‑arrays, rectifiers, and DC combiners, and a printed flexible mm‑wave lens that provides robust, bending‑resilient operation over more than 20 GHz of gain and angular bandwidth. In planar and bent conditions, the design achieves harvesting up to 2.83 m in its current configuration and exceeds 180 m with state‑of‑the‑art rectifiers, delivering several µW of DC power (≈6 µW at 180 m with 75 dBm EIRP).

Abstract

Abstract 5G has been designed for blazing fast and low-latency communications. To do so, mm-wave frequencies were adopted and allowed unprecedently high radiated power densities by the FCC. Unknowingly, the architects of 5G have, thereby, created a wireless power grid capable of powering devices at ranges far exceeding the capabilities of any existing technologies. However, this potential could only be realized if a fundamental trade-off in wireless energy harvesting could be circumvented. Here, we propose a solution that breaks the usual paradigm, imprisoned in the trade-off between rectenna angular coverage and turn-on sensitivity. The concept relies on the implementation of a Rotman lens between the antennas and the rectifiers. The printed, flexible mm-wave lens allows robust and bending-resilient operation over more than 20 GHz of gain and angular bandwidths. Antenna sub-arrays, rectifiers and DC combiners are then added to the structure to demonstrate its combination of large angular coverage and turn-on sensitivity—in both planar and bent conditions—and a harvesting ability up to a distance of 2.83 m in its current configuration and exceeding 180 m using state-of-the-art rectifiers enabling the harvesting of several μW of DC power (around 6 μW at 180 m with 75 dBm EIRP).