A miniaturized rectangular cavity by three-dimentional (3D) anisotropic metamaterials

In this letter, a further miniaturization approach for the exiting MCR design extending analysis to 3D isotropic case. It is shown that the subwavelength resonance occurs when transversal permeability components have opposite signs. In this case, the rectangular cavity supports subwavelength resonance, and the width and length of such the rectangular cavity resonator can be in principle simultaneously arbitrarily small. Based on these results, a IMCR filled partially with MSRRs, which transversal permeability component is negative, partially with a conventional material is designed and simulated. It is shown that the the length and width are simultaneously shortened by 70%, compared with a conventional cavity resonator. Those results indicate that the IMCR can be realized with only MSRRs or other structures with single negative permeability instead of a double-negative LHM, and the volume of the cavity resonator is only limited by the size of the unit cell of the double-ring. In fact, the structure with a single negative permeability is much simpler than a double-negative LHM in designs and fabrications.