Tunable notch filter of ferrite-filled grooves in parallel plates

The characteristics of tunable notch filter of ferrite-filled grooves in parallel plates are investigated. The Fourier transform and mode matching is used to obtain a simple, rigorous solution. The 8.6 to 11.3 GHz tuning has been achieved with the dc magnetic field varying from 0 to 5830oe. The comparison between our theory and measurement data using a rectangular waveguide shows a good agreement.