Cover story: He PH, Niu LY, Fan Y, Zhang HC, Zhang LP et al. Active odd-mode-metachannel for single-conductor systems. Opto-Electron Adv 5, 210119 (2022).

Although single-conductor transmission media possess many advantages compared to multi-conductor ones, they are still far away from systematic applications. Key reason of the underdevelopment of single-conductor systems compared to multi-conductor ones is the poor compatibility between single-conductor transmission media and active semi-conductor components. Single-conductor construction makes it difficult to produce sufficient electrical potential difference on transmission media for exciting active semi-conductor components including amplifier, harmonic generator and mixers. Thus, seeking a feasible method to break the bottleneck of single-conductor transmission media is still urgent. The research group of Prof. Tie Jun Cui from the Institute of Electromagnetic Space of Southeast University proposes a new kind of active odd-mode-metachannel (OMM) that can support odd-mode spoof surface plasmon polaritons (SSPPs) to perform as the fundamental transmission channel of single-conductor systems. The OMM is realized by introducing zigzag decoration into the typical SSPP structure to strengthen the field confinement and broaden the bandwidth of odd-mode SSPPs simultaneously, which makes it possible to achieve active semi-conductor component integration on planar single-conductor media. As an instance, an amplifier chip is successfully integrated on the single-conductor OMM to realize both loss compensation and amplification of signals. Meanwhile, the merits of OMM including crosstalk suppression, low radar cross section (RCS), and flexibility are comprehensively investigated in this work as well, which further demonstrates the application value of the active OMM. Hence, the proposed technology of active OMM breaks the major obstacle in developing single-conductor systems and provides a new avenue for future smart skins.