Dual Composite Right/Left-Handed (D-CRLH) Transmission Line Metamaterial

The novel concept of dual composite right/left-handed (D-CRLH) transmission line metamaterial is introduced. The D-CRLH is the "dual" of the conventional CRLH in the sense that it has a series parallel (instead of series) LC tank and a shunt series (instead of parallel) LC tank. This topological duality results in dual properties. The D-CRLH indeed exhibits its left-handed (LH) band at high frequencies and its right-handed (RH) band at low frequencies and is of stop-band nature, in opposition to the CRLH which is low-frequency-LH/high-frequency-RH and pass-band. The so-called balanced condition is still valid in the D-CRLH for broadband matching. However, phase origin is at dc and infinity instead, as at the LH-RH transition, and the gap between the RH and LH bands cannot be closed up in practical implementations. In contrast, the D-CRLH provides an unlimited LH bandwidth. This letter presents the homogeneous and LC-network transmission parameters and the fundamental dispersion/impedance properties of the D-CRLH