Modeling and Research of a Microstrip Ferrite Filter by Computer Simulation

Simulation of microwave tunable devices in programs that calculate multimode S-parameters greatly simplifies of the transmission line optimal parameters selection (dimensions and relative permittivity of the substrate, dimensions of conductors) and parameters of resonators. The paper considers the design and principle of a ferrite band-pass microwave filter operation. A microstrip two-resonator ferrite filter made on a dielectric material on which transmission lines are in the form of non-resonant length coupled microstrip lines. The resonators are made in the form of disks of yttrium iron garnet. Also, computer modeling of a microstrip filter in the HFSS Ansoft program was carried out, and the amplitude-frequency dependences of the filter characteristics on the geometry of strip lines and the thickness of ferrite resonators were obtained. Studies have been carried out for disk thicknesses from 50 to 130 µm. Microwave bandpass filters in the receiving devices play an important role in suppressing out-of-band signals.