Modeling of Electromagnetically Induced Transparency With RLC Circuits and Metamaterial Cell

The amplitude and phase characteristics of metamaterial cells consisting of microstrip and dielectric resonators (DRs) were studied. Circuits containing resonators of fundamentally different quality factors in the microwave range and excited on different types of oscillations have two independent energy ways, which allows the simulation of Fano resonances and electromagnetically induced transparency (EIT). The effects associated with the anomalous dispersion of the metamaterial cell as well as the associated positive values of the group delay (GD) are demonstrated. The experimental and calculated characteristics of metamaterial cells were compared. As the model of metamaterial cell calculation, the lattice circuit of an all-passing filter based on lumped elements was used. It was shown that the numerical calculations of systems exhibiting resonant phenomena (including the Fano effect) can be simplified based on the four-pole network containing the following parameters: unloaded, external, and loaded quality factors of resonators and detuning between their resonant frequencies. The calculated and measured characteristics were found to be in good agreement, which indicates the adequacy of the proposed models.