Properties of Envelope Pulses Developed in Coupled Nonlinear Composite Right- and Left-handed Transmission Lines

We investigate the properties of nonlinear envelope pulses developed in a coupled composite rightand left-handed (CRLH) transmission line with regularly spaced Schottky varactors. It is found that the dispersive distortion of the envelope pulses carried by each mode is well compensated by nonlinearity introduced by the varactors. In addition, we numerically observe that the collision of two nonlinear envelope pulses leads to the development of a new pair of envelope pulses (one traveling forward and the other backward). The newly developed pulses become maximal when phase-matching with the original pulses is established, and their carrier frequency is close to that of the harmonics of the colliding pulses.