Compact Substrate Integrated Waveguide Wideband Bandpass Filter With Post-Manufacturing Tuning Capabilities

[EN] In this paper, a miniaturized wideband bandpass filter in coaxial substrate integrated waveguide (SIW) technology is presented. To improve the response selectivity and coupling control, a multi-layer structure has been implemented, introducing both strong magnetic and electric couplings. To reduce the physical size of the device, surfaced-mounted device (SMD) capacitors have been integrated on the top layer. These allow both resonant frequency and capacitive coupling level control. Thus, a 4-th order Chebyshev filter with an absolute bandwidth (BW) of 2.9 GHz centered at 5.35 GHz has been designed, fabricated and measured. An extremely small filter size of 7 x 7 mm(2) has been obtained. A study of manufacturing tolerances are also presented in this paper, together with a post-manufacturing response correction allowed by the SMD elements. As it is shown in the paper, the filter's out-of-band rejection can be easily enhanced by introducing additional transmission zeros (TZs). This work was supported in part by the European's Union Horizon 2020 Research and Innovation Programme under the MarieSklodowska-Curie Innovative Triangle Networks (ITN) through TESLA under Grant 811232, in part by the European Space Agency(ESA) under Contract 4000124983, in part by the Ministerio de Ciencia e Innovacion (MICIN) through Spanish Government under the Research and Development Project PID2019-103982R-C41 and Project MICIN/AEI/10.13039/501100011033, and in part by the funding for open access charge: Universitat Politecnica de Valencia Messaoudi, EM.; Martínez Pérez, JD.; Boria Esbert, VE. (2023). Compact Substrate Integrated Waveguide Wideband Bandpass Filter With Post-Manufacturing Tuning Capabilities. IEEE Access. 11:2327-2341. https://doi.org/10.1109/ACCESS.2022.3233867