Abstract: Low pass equivalent processing is a method for use with a network analyzer, that gethers a sequence of NDATA samples, each sample including real and imaginary components of a signal, over a frequency range from F1 to f2 in frequency steps of (f2-f1)/(NDATA-1), where f1 is greater than zero. The sequence of samples is processed to estimate a characteristic of the signal with respect to a selected discontinuity in the signal. The sequence of samples is converted to time domain, to generate time domain data over a range from zero to t. The selected discontinuity is identified as lying within a range of t1 to t2. Next, the phase of the time domain data is unwound to correct a portion of the phase error resulting from the one sided spectrum that is not dependent on the distance to the discontinuity through the network. Next, the magnitude peak JMAX of the data samples between time range t1 to t2, is determined.