Modeling of asymmetric and unbalanced composite right/left-handed transmission line

摘要

The techniques in the parameter retrieval procedure based on Nicolson-Ross-Weir (NRW) approach are discussed for asymmetric composite right/left-handed transmission line (CRLH TL). A 10mm-long microstrip transmission line is calculated by the revised method for validation and comparison. An improved lumped parameter extraction in equivalent circuit modeling is proposed for unbalanced CRLH TL. The prototype CRLH TL proposed by Caloz et al is analyzed for illustration, which reveals that there is weak-unbalance in this prototype. The characteristic of band gap in unbalanced CRLH TL is fully recovered by the proposed algorithm. Finally, good agreement is observed between the response in circuit modeling and the simulation results in practical structure. The potential application of the algorithm lies in efficient guidance and validation for new designs of CRLH TL structures.