Numerical modeling of a stripline antenna in a large semi-anechoic chamber

Stripline antennas are used for automotive immunity testing in semi-anechoic chambers at low frequencies (<30 MHz). In order to investigate the behavior of such devices, a numerical model of the radiating elements of such a system has been developed using a 3D field modeling technique (TLM). The field distribution beneath this structure has also been measured for comparison with the computed results. At the operating frequencies of these antennas the absorbing lining of the chamber is too thin to provide significant absorption. Nonetheless, it is found that the presence of even an electrically thin layer of lossy material has a significant impact on the computed performance characteristics of the antenna. It is concluded that the absorbing lining must be represented in models that are used for the investigation and optimization of stripline antennas