Design of planar LHM with broad bandwidth and miniaturized cell

In 1968, the idea of left-handed metamaterial (LHM) with simultaneously negative permittivity and permeability was conceived by Veselago. Although the LH property is no longer questioned, the performance including the bandwidth, loss and the unit cell size of the LHM are still calling for improvement. In view of this consideration, a C band planar LHM, in which the unit electrical cell size is 0.067 and relative bandwidth is 56.4%, is designed with CST´s Microwave Studio (MWS) simulation tools. The reflection (S11) and transmission (S21) results are given for the scattering of the normally incident plane wave from the LHM slab constructed from the SSRR (split square ring resonator). The effective permittivity and effective permeability of the LHM are extracted from the reflection and transmission data based on Nicolson-Ross-Weir (NRW) approach. Calculation results show that the effective permittivity and effective permeability are simultaneously negative within 4.2~7.5 GHz. In addition, in order to verify the double negative (DNG) property the reflection (S´11) and transmission (S´21) for the scattering of the normally incident plane wave from an ideal uniform LHM slab described by Drude model, which is equivalent to the composite one, are simulated. Results show the S´11 and S´21 are in good agreement with S11 and S21 for both magnitude and phase, respectively