Element Coefficients for Symmetrical Two-Section Filters Having Tchebycheff Response in Both Pass and Stop Bands

Element coefficients for a normalized symmetrical low-pass filter, having "equal ripple" response in both pass and stop bands, are presented graphically. The coefficients are plotted against the relative selectivity of the filter, with a loss factor as independent parameter. The interval between curves is sufficiently small to permit interpolation with an accuracy of
\pm 1
per cent. Frequency and impedance transformations are included to allow the elements of a practical filter to be derived from those of the appropriate normalized design. The loss function corresponding to a particular design is readily formulated in terms of the loss factor above and the appropriate frequencies of zero loss.