A Small Dual-Band Asymmetric Dipole Antenna for 13.56 MHz Power and 2.45 GHz Data Transmission

Despite the disparity between typical small antenna designs for wireless powering and far-field radiation, this letter proposes a single asymmetric dipole antenna for both applications on a printed circuit board (PCB) of dimension 10 × 24 mm
²
. In this design, current cancellation is applied as a technique to enhance far-field radiation efficiency while maintaining inductive wireless power transfer performance. The measured radiation efficiency at 2.45 GHz is 57%, and the power transfer efficiency at 13.56 MHz over a distance of 20 mm is 2.15 dB. The results demonstrate the feasibility of a single dual-band antenna operating at two distinct frequencies while attaining reasonable efficiencies.