A fast network analyzer for the frequency range of 10 MHz to 4 GHz

The developed network analyzer with four channels allows very fast measurements of S-parameters in a frequency range from 10 MHz up to 4 GHz. This is possible because highly linear analogue frequency ramps are used. Thus the settling times of stepped frequency sweeps of conventional analyzers are eliminated. The required high linearity and high stability of the frequency ramps are achieved by using fractional divider phase locked loop circuits. The signal processing from the fast network analyzer differs from that of the conventional network analyzer. The analytical signal is determined by a double Fourier transformation of the complete frequency sweep. Conventional calibration procedures are then applied in order to correct the systematic errors of the fast network analyzer.