Toward 5G Wireless Power Harvesting: A Promising Broadbeam Equiconvex Lens-Integrated mmWave Harvester for Smart City Environments

For the first time, the authors propose a 3-D lens-enabled, broadbeam energy harvester capable of mW-level of harvested power across a wide angular coverage. The design incorporates a 25-rectenna “pixel” array, each featuring a circularly polarized antenna with a highly sensitive half-wave rectifier, and an equiconvex 3-D dielectric lens to enhance power capture and angular coverage. In a proof-of-concept testing, the harvester achieved a peak power capture of 6.5 mW and maintained mW level of harvested power, at incident power densities as low as 0.1 mW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, across a broad solid angle of 2.68sr, representing the highest combined harvested power across angular coverage among mmWave harvesters. With 5G/mm-Wave EIRP of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm {75~dBm}$</tex-math> </inline-formula>, the harvester can theoretically capture 6.5 mW at 40 m and sustain 1 mW out to 80 m. With broadbeam coverage and efficient energy harvesting, this system enables advanced smart city applications while reducing reliance on traditional power sources.