Abstract
        A novel bandpass filter design using eighth-mode substrate integrated waveguide resonators is proposed. Resonators’ 
coupling is realized using a conductive bridge which may be tuned to achieve desired coupling coefficient. This realization 
overcomes the PCB resolution, i.e. the minimal gap between the resonators. An equivalent circuit is derived for the secondorder bandpass filter using a series inductor as the coupling bridge. Design curves of the external quality factor and 
coupling coefficient are proposed as closed form expressions. Filter prototypes are fabricated on FR4 substrate. The 
obtained responses show good agreement with 3D electromagnetic simulations, thereby validating the proposed filter 
design.
        Keywords
        Bandpass filter, Conductively coupled resonators, Eighth-mode SIW resonator, Equivalent circuit, Substrate integrated waveguide.
        Citation
        MILOŠ RADOVANOVIĆ, SNEŽANA STEFANOVSKI PAJOVIĆ, MIODRAG TASIĆ, MILKA POTREBIĆ, DEJAN TOŠIĆ, Bandpass filters with conductively coupled eighth-mode  SIW resonators, Optoelectronics and Advanced Materials - Rapid Communications, 16, 9-10, September-October 2022, pp.443-449 (2022).
        Submitted at: Dec. 5, 2021
 
        Accepted at: Oct. 5, 2022