The characteristics of two-stage composite right- and left-handed (CRLH) transmission lines are discussed. The dispersion relationship of both balanced and unbalanced two-stage CRLH lines is described, together with numerical calculations that demonstrate their potential.

The characteristics of a left-handed traveling-wave transistor, which is formulated as two composite right- and left-handed (CRLH) transmission lines with both passive and active couplings, are discussed for generating unattenuated waves having left-handedness. The design criteria for convective instability are described, together with results of numerical calculations that solve the transmission equation for the device.