Frequency dependence of loop antenna H-Field in free-space

Thumbnail Image
Su, Zhen
O'Callaghan, Brendan
Kumar, Sanjeev
O'Flynn, Brendan
Barton, John
Bulja, Senad
O'Hare Daniel
Buckley, John L.
Journal Title
Journal ISSN
Volume Title
Royal Irish Academy, RIA
Published Version
Research Projects
Organizational Units
Journal Issue
This paper investigates the effect of frequency on the magnetic field (H-field) strength at a specified distance from a single turn transmitting (TX) loop antenna in free-space. The H-field of a TX loop antenna in the Near Field (NF) region can be estimated using Biot-Savartâ s Law (BSL). However, the BSL method is only valid for DC current flow and does not consider the effects of frequency on the H-field strength. This work introduces the frequency-dependent Antenna Near Field (ANF) method reported in the literature and compares this method against the BSL method and EM simulation results. It is shown that the ANF method can estimate the H-field magnitude with an error of less than 5% when compared with finite-element methods (FEM). In addition, the ANF method computes in a fraction of a second, whereas the FEM method takes several minutes to compute.
Antenna near field , Inductive coupling , Wireless power transfer , Biot-Savart's law , Magnetic field , Loop antenna
Su, Z., O'Callaghan, B., Kumar, S., O'Flynn, B., Barton, J., Bulja, S., O'Hare, D., and Buckley, J. L. (2022) 'Frequency Dependence of Loop Antenna H-Field in Free-Space', The 19th RIA/URSI Research Colloquium on Radio Science and Communications, Dublin, Ireland, 26-27 Oct.