Substrate integrated waveguide filter based on the magnetized ferrite with tunable capability

Abstract

AbstractIn this paper, a miniaturized substrate integrated waveguide filter on the magnetized ferrite is presented. The proposed filter has a small size, high power transmission capability, relatively good bandwidth, and tunable frequency bandwidth. This filter is tunable due to the magnetic bias applied to the ferrite substrate. Compared to the tunable filters reported in previous references based on PIN diode, varactors, and mechanical changes, the proposed filter has a relatively wide adjustment on the operation frequency. Using this method dramatically reduces the complexity of the external control system. This tunable filter is optimized using the Ansoft HFSS software and then fabricated. The measured operating frequency of the filter is tunable from 5.3 to 7.15 GHz by changing the magnetic bias from 100 Oe to 1100 Oe. In the frequency range of 5.55 to 6.95 GHz, an insertion loss of less than 1.1 dB and a return loss of better than 20 dB are achieved. A good agreement between the simulation and experimental results was achieved.