Mutual synchronization of oscillating pulse edges in point-coupled transmission lines with regularly spaced tunnel diodes

•Mutual synchronization of edge oscillations in point-coupled tunnel diode transmission lines is investigated.•Phase reduction scheme is applied to evaluate phase difference/frequency shift between the synchronized edges.•Results of time-domain calculations validate the phase reduction scheme.

In this paper, we investigate the mutual synchronization of oscillating pulse edges developed in point-coupled transmission lines periodically loaded with tunnel diodes (TDs). When supplied with an appropriate voltage at the end of a TD line, a pulse edge exhibits a spatially extended limit-cycle oscillation on the line. In this study, the properties of this mutual synchronization of edge oscillation established in two coupled TD lines are discussed. We examine the mutual synchronization using phase sensitivity calculated by applying phase-reduction scheme to the transmission equation of a TD line. The phase difference between the synchronized edges and oscillation frequency is calculated depending on the coupling cell. We then validate the reduced model via time-domain calculations of edge oscillations.