A super-compact balanced multi-layered CRLH transmission line with wideband LH properties for microwave phase engineerings

This paper newly proposes a balanced multilayered (ML) CRLH transmission line (TL) with defected parallel plates. This TL is super-compact in size (a body of the unit-cell is only 2.0 times 2.0 times 0.67 mm³) and has an ultra-wide passband from 1.8 GHz to 8.7 GHz which fractional bandwidth (FBW) corresponds to 131 % for the center frequency fc = 5.25 GHz) including a very wide left-handed (LH) region from 1.8 GHz to 6.8 GHz (116 % FBW of LH region for fc = 4.3 GHz). The well-balanced CRLH TL with quasi-LH properties is demonstrated for the first time both theoretically and experimentally. This ML architecture is quite useful for phase engineerings in the microwave devices using the phase-advanced properties in the ultra-wide LH region.