Compact reconfigurable triple‐mode triple‐band substrate integrated waveguide bandpass filter

In this study, a reconfigurable triple-band triple-mode substrate integrated waveguide filter is designed and fabricated in the C-band spectrum. A novel and simplified design procedure based on analytical equations is proposed. The filter design also benefits from a reconfigurable structure, using metallic via holes as perturbation, allowing wide-band selectivity of the C-band spectrum (from 4.4 to 6.9 GHz). Moreover, the filter benefits from a magnetic coupling solution between the resonators, which only couples the first three modes and rejects the next resonating modes. Therefore, a large bandgap in the spectrum is achieved. The proposed structure is fabricated and measured, and a high similarity between the simulation and fabrication is observed. The measured results show that the first band can be tuned in the frequency range of 4.4 to 7, the second band can be tuned in the range 5.8 to 7.7 GHz, and the third band from 5.8 to 7.7 GHz. The insertion loss 1.5 to 2.5 dB, 2 to 3 dB, and 2.5 to 3.5 dB for the first, second, and third bands, respectively.