Improving the accuracy of radiated emission measurements for frequency below 30 MHz by using a fiber optic isolated rod antenna

An ongoing commitment to reducing undesired physical phenomena, typical of radiated emission tests at frequencies lower than 30 MHz, has led to several revisions of the standards and to different approaches for civil, military and aeronautical applications and devices with internal combustion engines. This made it impossible to compare results from different sectors and across different versions of the same standard. The use of an innovative rod antenna, with embedded receiver and data transfer via optical fiber, allowed us to analyze and compare various setups and showed that certain elements, introduced with the intention of improving the repeatability of measurements, actually made the measurements more random as well as less reliable in absolute values. We concluded that simplifying a setup, by removing the coaxial cable and the parts thought necessary to minimize its effects, improves repeatability while bringing the result closer to that achieved under undisturbed field conditions.