DESIGN OF OPEN STRIPLINE WITH COAXIAL IMPEDANCE MATCHING UNIT FOR AUTOMOTIVE EMC MEASUREMENT

Abstract

In this thesis, the design process and construction method of a stripline for electromagnetic immunity testing is described. The stripline consists of parallel plate transmission lines and characteristics impedance of the stripline was determined to be 150 Ω. The size of the OSL is 200 cm in length, 60 cm in width and 80 cm in height according to CISPR 20. It was verified through TEM verification and field uniformity measurements performed according to the IEC 61000-4-20 standards. By using the tapered coaxial impedance matching unit, its power capability was determined only by the power capability of the terminating load. High power can be injected to the stripline through the tapered coaxial matching unit, and the high intensity field is generated inside the stripline. An open stripline according to the standard CISPR 20 can be used to test equipment up to 70 cm. TEM verification and Field uniformity by IEC 61000-4-20 standards were evaluated in 9 test points at 253 frequencies of the frequency range from 100 kHz to 200 MHz with an increasing frequency step size of 5 % in 10 kHz ~ 80 MHz and 1 % in 80 MHz ~ 200 MHz. The statistical approach and calculation approach results of the TEM mode and field uniformity verification for 75 % of the test points and 6 dB criteria were satisfied.