Novel Bandpass Filter Using Metallic Photonic Crystal Structure

A conventional metallic photonic crystal (M-PhC) point-defect-cavities(PDC) can be realized by removing a rod from the periodical structure. Therefore, to keep the periodicity, the resonant frequency of such cavity is difficult to be changed. In this paper, a novel class of PDCs is constructed by putting a metallic/dielectric rod at the center of the cavity. By changing the radius of the central rod, the resonant frequency can be easily-tuned. After the calculation of band structure of a square-lattice PhC for TE/TM modes, the resonant-frequencies the cavity are calculated and illustrated. Finally, a PDC-based filter is designed to show its potential applications in microwave regime.