Microwave multichannel tunable filter based on transmission and reflection properties of 1D magnetized plasma photonic crystal heterostructures

Abstract

The transmission and reflection properties of one-dimensional magnetized plasma photonic crystal heterostructures have been theoretically investigated. The proposed structure is composed of two sub-PCs containing magnetized cold plasma and lossless dielectric materials. The optical properties of the structure are suitable for multichannel tunable transmission filter and omnidirectional band-stop filters applications. The investigations have been carried out by applying transfer matrix method and employing electrostatic boundary conditions for TE and TM wave, respectively, in microwave region. The transmission spectra of the proposed structure possess external magnetic field-dependent 3N − 3 comb-like resonant peaks called as transmission channels for period number (N) > 1. Due to multiple interactions between forward and backward decaying evanescent waves in plasma and dielectric layers, respectively, 3N − 3 transmission channels are found in defect-free magnetized plasma photonic crystal heterostructure, enabling the structure to work as a multichannel filter. Next, the filter properties have been made tunable, i.e., channel frequency of each channel can either be red or blue shifted, depending upon the RHP and LHP configurations of external magnetic field under magneto-optical Faraday effect, respectively. The number of channels and their positions can also be modulated by changing the number of periods (N) and the incident angle (θ0) for TE and TM waves both besides other plasma parameters. Apart from the transmission properties of the proposed structure, we have also studied the reflection properties to obtain multichannel tunable omnidirectional photonic band gaps under the influence of external magnetic field. These results may be utilized to develop new kind of externally tunable single to multichannel omnidirectional band-stop filters.