Dual-Band Filter Composed of Dielectric and Waveguide Resonators with In-Band Transmission Zeros

This paper presents the design of a hybrid narrowband dual-band bandpass filter with in-band transmission zeros (TZs) in the Ku-band, whose passbands are realized by different types of resonators. The upper passband is realized by waveguide resonators, while the lower one is implemented by TE01δ mode dielectric resonators (DRs). The filter synthesis process is based on using frequency transformation. To validate the mixed resonator design, the proposed filter is manufactured and the measurement results are compared with the simulation. The passbands of the manufactured filter are designed for a bandwidth of 40 MHz and center frequencies of 13.47 GHz and 14.05 GHz, respectively.