Ferrite-Loaded Substrate Integrated Waveguide Frequency-Agile Bandpass Filter

摘要

In this paper, a ferrite-loaded substrate integrated waveguide (SIW) frequency tunable bandpass filter is presented. Two ferrite slabs are loaded at sidewalls of an SIW. When a DC magnetic bias is applied to the ferrite slabs, the equivalent width of the ferrite-loaded SIW is changed, which contributes to the tuning ability. As an example, a ferrite-loaded SIW frequency-agile bandpass filter is designed and fabricated according to this principle. Its center frequency can be adjusted from 12.35 GHz to 13.2 GHz. Within this frequency range, the insertion loss is changed from 2.3 dB to 3.9 dB and the return loss is better than 10 dB.