Additional Pulses in the Time Response of a Modal Filter on a Double-Sided Printed Circuit Board.

A quasistatic approach was used to consider the occurrence of additional pulses (APs) in the modal filter (MF) realized on a double-sided printed circuit board, as well as in the three structures obtained from it by removing one reference conductor. It is shown that, for all investigated MFs, the AP delays are determined by a linear combination of per-unit-length mode delays multiplied by the line length. It was found that there are no APs between the pulses of modes with one pass along the line, while they appear with three or more passes. It is revealed that in each of the considered MF structures (except the one without upper-right reference conductor), the APs have greater amplitudes of mode pulses with a triple pass. It was demonstrated that the removal of the reference conductors affects the number, polarity, and amplitude of the APs. [ABSTRACT FROM AUTHOR]