A New Approach for the Analysis of Planar Distributed Two-Dimentional (2-D) Left-Haned (Lh) Structures

A new approach is proposed to analyze planar distributed 2-D LH structures. The 4-port S parameters of the unit cell combined with the Bloch-Floquet theory are used to determine the dispersion relations and Bloch impedance. The LH and RH frequency bands are identified by the signs of the real parts of the wave number and the Bloch impedance. Several advantages of the new approach over the previous unit cell analysis methods are presented. As an example, a capacitance-enhanced LH structure is designed and analyzed with the new approach. FDTD simulation is also performed to study the periodic LH structure with infinite arrays. The results of the simulation at the LH frequency band show the backward wave properties in consistent with those obtained by the proposed approach.