A Near Field Focused Lens Antenna for Wireless Power Transmission Systems

A near field (NF) focused lens antenna fabricated by the 3D printing method for wireless power transmission (WPT) systems are proposed in this paper. The lens antenna operating at Ka band, is employed as the transmitting antenna to focus the electromagnetic power and reduce the diffraction loss during power transmission in free space. The aperture size is 100.8*100.8mm, with a designed focused length of 300mm, while measured results show that the maximum power density occurs at 215 mm along z-position. 3D printing material resin with a permittivity of 2.87 and loss tangent of 0.01 is adopted. Comparison between proposed focused antenna and conventional high-gain antenna in terms of transmitting efficiency is carried out and results show that an improvement of 9.7% can be achieved within a circular area of 50mm radius at the 300mm- plane.