Characterization of lossy transmission lines of arbitrary characteristic impedance by time domain measurements

This paper deals with the characterization of lossy transmission lines. The method developed here delivers the complex propagation coefficient ¿ and the characteristic impedance of any arbitrary characteristic impedance transmission line, embedded in an arbitrary environment. This approach is based upon time domain analysis, made with a commercial sampling oscilloscope. The method only requires the realization of two transmission lines of different lengths and allows a complete correction for the systematic errors of the measurement system. The problem of the random errors is also addressed and a sensitivity study on the effects of random errors is made. The method is demonstrated with microstrip transmission lines. A comparison of the developed technique with a classical frequency domain extraction is also carried out.