Influence of the Antenna's Height to the Standing Waves Ratio When Performing the Electromagnetic Susceptibility Tests in Anechoic Chambers

摘要

Immunity tests to radiated electromagnetic field are one of the most common tests performed within the framework of the electromagnetic compatibility. These tests are performed inside a shielded chamber provided the requirements given by the appropriate standards are kept. As the levels of the generated fields can be high and the output power of the transmitting amplifiers cannot be infinite, it is necessary to achieve a good performance of the transmitting antenna. By means of the real experiment the author of this paper shows how the height of the antenna placed above the conductive floor can affect the antenna's voltage standing waves ratio and how this phenomenon affects the parameters of the whole measurement system.