Design of dual-mode substrate integrated waveguide filter using inductive slots

This paper presents a single-cavity dual-mode bandpass filter design based on a substrate integrated waveguide (SIW) resonator. The proposed resonator has various types of inductive loading, such as symmetrical/asymmetrical, thin and narrow slots which are used to achieve a compact circuit size. The presented structure has also a new perturbation arrangement for dual-mode SIW resonators depending on the movement of narrow slots. The designed structure is fabricated for the experimental verification of the proposed model. According to measured results, center frequency is obtained at 5.1GHz with a fractional bandwidth of %4.5. The measured insertion and in-band return losses are about -1.24 dB and about -15.4 dB, respectively. Measured results show a good agreement with the simulated results.