Dual-Band Bandpass Filter Based on Two Pairs of Degenerate Modes of a Regular Hexagonal Prism Dielectric Waveguide Resonator

In this work, a novel dual-band single-cavity dielectric waveguide (DW) bandpass filter (BPF) is proposed. Two pairs of degenerate modes, i.e., TE
121
, TE211, TE122, and TE212, are excited in a regular hexagonal prism. The resonant frequencies of each mode can be controlled by the length and height of the regular hexagonal prism. Thus, the center frequencies and bandwidths of each passband can be controlled to some extent. For verification, a 5.6 GHz / 6.54 GHz DW BPF with equal ripple of 0.0432 dB and FBW of 2.8% / 3.4% is designed. Simulated results show that the bandwidth and center frequencies of proposed dual-band BPF can be easily controlled.