A Microstrip Composite Right/Left-Handed Transmission Line without Vias

摘要

The left-handed (LH) transmission line (TL) is a transmission line which supports backward waves. In this report, a novel via-free microstrip meta-structured left-handed (LH) transmission line (TL) is proposed, when is suitable for low cost LH TL fabrication. The dispersion characteristics of the TL are theoretically obtained based on circuit theory, and the condition for which the TL exhibits the LH characteristics is obtained. The composite right/left-handed (CRLH) property of the TL, in which the TL exhibits both the LH and right-handed (RH: forward wave support) properties, is also shown theoretically, and the condition in which the TL has a smooth transition between LH and right-handed (RH) modes without a bandgap (balanced CRLH condition) is obtained. Experiments on selected prototypes are carried out, and the LH characteristics are demonstrated in terms of transmission and reflection characteristics. In addition, the TL structure is applied to a leaky-wave antenna and backward and forward radiations are demonstrated experimentally.