A Helmholtz coil for high frequency high field intensity applications

In this work a general introduction to Helmholtz coil is presented and then attention is drawn to the implementation of a wideband (50 kHz) coil for applications requiring high magnetic flux density (up to a few mT) for sensor calibration, immunity tests and exposure of biological specimens. Experimental characterization confirms that field uniformity is quite good: dispersion is within 1.5% and 0.35% inside cubic volumes of 25% and 10% of the coil side respectively for the larger spacing; the measured impedance and the self resonance frequency are in accordance with the proposed simplified model; the magnetic field expanded uncertainty with k=2 is less than 0.5%.