Title :
Characterization of loaded TEM-waveguides using time-domain reflectometry
Author :
Kärst, J.P. ; Garbe, H.
Author_Institution :
Inst. fur Grundlagen de Electrotech. & Messtech., Hannover, Germany
Abstract :
An approach is presented to characterize the load state of a TEM-waveguide using the local characteristic impedance Zc(z) derived from time-domain reflectometry (TDR) measurements. The field homogeneity and the field polarization can be estimated using the deviation from the intended Zc=50 Ω of the empty TEM-waveguide. Considering wave propagation only in the TEM-mode an analytical relationship between load state and characteristic impedance is derived. Multiple reflections due to the nonuniformity of the loaded TEM-waveguide and higher order modes excited by the load are taken into account. Experimental results are presented using a GTEM-cell with several load states
Keywords :
electric impedance measurement; electromagnetic compatibility; electromagnetic fields; electromagnetic interference; electromagnetic wave polarisation; electromagnetic wave reflection; time-domain reflectometry; waveguide theory; waveguides; EMC test sites; EMI; GTEM-cell; TDR; TEM-mode; emission measurement; empty TEM-waveguide; experimental results; field homogeneity; field polarization; higher order modes; load states; loaded TEM-waveguides; local characteristic impedance; multiple reflections; susceptibility measurement; time-domain reflectometry measurements; wave propagation; Impedance measurement; Polarization; Reflection; Reflectometry; Shape measurement; Testing; Thumb; Time domain analysis; Time measurement; Velocity measurement;
Conference_Titel :
Electromagnetic Compatibility, 1999 IEEE International Symposium on
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-5057-X
DOI :
10.1109/ISEMC.1999.812881
