A Magnetically Tunable Dual-mode Bandpass Filter for Cognitive Wireless System

A novel magnetically tunable bandpass filter for cognitive wireless system is proposed. The filter is based on substrate integrated waveguide (SIW) dual-mode resonator with ferrite slabs loaded near the regions of strongest magnetic field of TE₁₀₂ and TE₂₀₁ modes. With changing of the magnetic biasing filed, the center frequency of the filter can be tuned. The final results show that the proposed bandpass filter exhibits a tunable frequency range of about 11.27% from 11.8 to 13.13GHz with a magnetic biasing filed from 0T to 0.4T.