A new quasianalytical method the multipole theory (MT) method is described
for the computation of cutoff wave numbers of TE and TM modes in a rectangu
lar coaxial transmission-line family. An extensive comparison with the exac
t data of the literature and various configurations of a rectangular transm
ission-line family shows the accuracy and flexibility of the quasianalytica
l MT method. it has been shown that the MT method is an effective approach
for the analysis of TE and TM modes in a rectangular transmission-line fami
ly. (C) 2000 John Wiley & Sons, Inc.