  Generalized coupled-line all-pass phasers, based on transversally-cascaded
(TC), longitudinally-cascaded (LC) and hybrid-cascaded (HC) coupled
transmission line sections, are presented and demonstrated using analytical,
full-wave and experimental results. It is shown that for N commensurate
coupled-line sections, LC and TC phasers exhibit N group delay peaks per
coupled-line section harmonic frequency band, in contrast to the TC
configuration, which exhibits only one peak within this band. It is also shown
that for a given maximum achievable coupling-coefficient, the HC configuration
provides the largest group delay swing. A wave-interference analysis is finally
applied to the various coupled-line phasers, explaining their unique group
delay characteristics based on physical wave-propagation mechanisms.
