Optimization of electrical properties of parallel plate antenna for EMC testing

摘要

Parallel plate antennas (also known as improved TEM-cell or strip line antenna) are used in electromagnetic compatibility for radiated immunity and interference testing. Appropriately designed antenna represents a transmission line with TEM wave propagation and uniform electromagnetic field distribution between plates for specified frequency range. Device under test is positioned within the region of uniform EM field. In this study, we aimed to optimize electric properties of a small parallel plate antenna which was primarily designed for telecommunication devices testing. We hypothesized that initial design of the parallel plate antenna could be improved in terms of S-parameters by optimizing the impedance matching. Parametric optimization was based on numerical analysis using the finite element method; as an outcome, we achieved approx. 15 dB improvement of S11 parameter and verified the results by measurements. Thus, the optimized parallel plate antenna needs considerably less input power for the same field intensity within the specified frequency spectrum.