Mutual Coupling Correction Factor for Optimized Multiaxis Shielded Loop Antenna Magnetic Field Measurements

Standard measurement procedures CISPR 36 for magnetic field measurements below 30 MHz is time consuming. To maintain realistic measurement time, standards limit the amount of the measurement positions and antennas orientations as well as evaluation of the operational modes of the electric vehicle being tested. This article introduces a multiaxis shielded loop antenna (MSLA) for magnetic field measurements below 30 MHz, proposing a new measurement approach that evaluates all three orientations simultaneously, significantly reducing the required time. The proposed methodology employs multichannel time-domain measurements, providing access to all three axes simultaneously. The article thoroughly analyses the effects of the MSLA construction on the measurement results under the influence of the mutual coupling (MC) effect between the antennas. The available phase information from each measurement axis due to the proposed measurement method is used to utilize the MC correction factor. Altogether, the novel multiaxis measurement setup with the provided MC correction factor can greatly improve measurement accuracy of the MSLA and drastically reduce standard measurement time.