The conjugately characteristic impedance transmission lines (CCITLs) implemented by lossless periodic transmission-line (TL) structures can exhibit active characteristic impedances (negative characteristic resistances). In this case, the magnitude of the voltage reflection coefficient is always greater than or equal to unity for passive load terminations. Due to complicated equations involved with terminated finite lossless periodic TL structures, the graphical tool called the modified extended ZY T-chart has been recently developed to assist in the analysis and design of these structures. This paper presents applications of the modified Tchart for problems associated with CCITLs with active characteristic impedances. In the determination of input impedances of terminated CCITLs, it is found that the modified T-chart yields sufficiently accurate results compared to those obtained from the extended ZY T-chart.