Testing immunity to portable transmitters with helical antennas: Key concepts

Radiated immunity testing in the automotive industry is an activity with ever increasing importance. Immunity tests are being performed in the semi-anechoic chamber of the EMC laboratory, within Continental Automotive Romania. Testing results rely on measurements performed by operators and nominal parameters of the equipment involved, which are input to the testing software. In this paper, we show how deviations of the equipment parameters from nominal values influence the testing outcomes. We performed measurements of impedance and VSWR's of antennas and directional couplers involved in EMC radiated immunity to portable transmitters testing. The results can be used for devising correction procedures for the testing software in order to improve the reliability of the tests.