Miniaturized Triple-Mode Bandpass Filter using Dielectric Resonators

This paper presents a compact triple-mode dielectric resonator bandpass filter based on a single waveguide cavity. Two barium titanate pucks are used in the design, placed in the middle of the metallic cavity to reduce the size of the filter. A third-order simplified Chebyshev bandpass filter is selected to verify the technique and simulated using HFSS software. The input and output coaxial probes are used to excite the degenerate EH11 modes, while the TM01 mode is excited using a vertical hole etched in the top of the barium titanate pucks. The resonator offers a size reduction ratio of about 15.6% compared with equivalent air-filled coaxial filters. The filter has finite transmission zeros on the high or low side of the passband.