Dual-band half-cut dielectric resonator filters

This paper introduces a dual-band filter using Dielectric Resonator (DR) technology, based on the half-cut cylinder resonator. Two orthogonal modes of the resonator are used to carry the two operating passbands of the filter. It is shown that full control over the two passbands is achieved, through the independent control of the center frequencies, inter-cavity couplings, and input/output couplings of each band. Filter design is simple and is carried out separately for each band, owing to the orthogonal modes. Spurious improvement techniques are also discussed. Designs are presented, and measurement results show the validity of the proposed concept. These filters harness the high Q feature of DR technology for dual-band filters.