Study on noble concept of transmitting signal assisted with evanescent wave energy

摘要

This study proposes a new concept for improvement of transmission characteristics at Gbps region even in wire length longer than 100 m. Our idea is characterized by adding evanescent energy to the common propagating signal energy along a metal wire. The evanescent wave constantly emits and scatters electromagnetic energy to air field due to not a little attenuated signal energy. Reuse of the evanescent energy may asist the propagating signal energy for long-distance signal transmission with lesser attenuation along metal wires. On the basis of this idea, principle experiments were performed to clarify based on the previous study. In this study, trial shielded twisted pair (High-Zo) wires were fabricated as more commercialized base, and their transmission characteristics such as eye-patterns were measured and compared with the unshielded twisted pair Category 6 (CAT 6) cables. Despite its 7 times higher DC resistance than the CAT 6 cable, the High-Zo wire exhibited superior transmission characteristics than the CAT 6 cable. Also, higher characteristic impedance (200 Ω) of the High-Zo wire was found to play an important role to outspread electromagnetic energy to air. As a result, it can be supported that two kinds of energy transmission modes, the evanescent and the conventional propagating waves, exist. Thus, the evanescent wave can assists signal transmission with matched energy timing. This invention might impact long-distance signal transmission systems.