On the Electric Field Distribution in Radiated Emission Rod Antenna Test Setups: Numerical Analysis and Experimental Validation

Abstract

The use of a vertically oriented rod antenna is requested by several standards for the measurement of radiated emissions below 30 MHz both from civil and military equipment. In all the cases, the measurements are performed with the antenna at short electrical distances from the equipment under test. The measurement results depend on the geometrical and electrical parameters of the setup in a not negligible and complex way. For this reason, during the years technical committees have tried to define a setup with boundary conditions able to provide the same measurement results whenever repeated. To that end, different bonding solutions for the counterpoise of the rod antenna have been proposed, obtaining different advantages and drawbacks. In this framework, in this article the authors describe the results of numerical and experimental analysis activities performed on the spatial distribution of the electric field under measurement in the proposed measurement setup. The activities have been done in order to define the optimal operative conditions that allow to obtain measurement results providing a faithful representation of the disturbance field generated by the equipment under test in undisturbed conditions, i.e., the field under measurement. Experimental activities have been performed with an innovative rod antenna with an integrated receiver that can also be operated in a completely isolated mode by using an optical fiber interconnection for its remote control.