The objective is the design an artificial delay line, composed by constant lumped elements, simulating a true delay line. Mathematically this means replacing an essential singularity at infinity of the complex frequency plane \(s= \alpha+ i\omega\) by a certain number of poles and zeros in the finite part of the latter. This objective is “attained” by means of pure phase-shift networks. The error of this approximation is considered to be the deviation of the resulting phase shift from a liner one (in \(\omega\)). Three estimes of this deviation are given.
The terminology used obscures the link to the physical performance.