Keynote speaker 1: Antennas for high power applications

Abstract

This talk presents antenna systems for high power applications to test electric equipment and discuss the issues of measurement facilities. Before releasing new electrical products, EMS (Electromagnetic susceptibility) tests are required to verify whether EUT (Equipment under test) causes the malfunction by a peripheral electromagnetic radiation. The EMS test needs to irradiate EUTs by high electric field in wide frequency range inside anechoic chamber. A problem in this facility is the antenna size in HF band, because the limited chamber space forces to design electrically small antenna with high power handling capability. In addition, EUTs under test are placed in the vicinity of the antenna, it is necessary to predict electric near field distributions. The antenna design for this application, this talk presents a multi-element folded dipole antenna in HF band and a pyramidal horn antenna in UHF band. The technique of antenna parameter optimization to provide high electric field at EUT is discussed in detail. The second topic of antennas for high power applications is the anechoic chamber design including with very small reflection from absorbers. Anechoic chambers do not provide artificial free space for antenna measurements. Small reflections from absorbers generate standing waves inside chamber and change the estimated electric field distributions inside chambers. The antenna design including small reflections from absorbers is also discussed to optimize EMS antennas.