Tunable Filters Based on Fano Resonance Using Asymmetric Moving Resonators in a Single Loop System

Abstract

We report a novel characteristic of the phenomenon of Fano resonance obtained by the interaction of incident electromagnetic waves and waveguides system formed of loop and resonators. The Green Function Method (GFM) is employed to calculate the transmittance of the incoming electromagnetic waves. Our proposed system achieve a selecting and filtering device either by total transmission or by total reflection with a very high performance. The proposed structure contains four segments of the same lengths, and asymmetric resonators (N and N ′ resonators) are moving in the structure. Through parameters optimization, we show that the system creates Fano resonances, which are sensitive to the variations of the segment lengths, the resonator lengths, the positions of the resonators, and the physical properties of the system components. Then, the proposed system is able to filter at least two resonance modes with different frequencies. This system has potential applications in the field of microwave communication antennas.