Experimental validation of analysis software for tunable microstrip filters on magnetized ferrites

Measurements are presented for microstrip filters on layered media containing magnetized ferrites. The measurements show that the filters can be tuned by adjusting the magnitude of the magnetic-bias field. The measured results are compared with full-wave numerical results obtained by the authors via the method of moments in the spectral domain. The agreement between experimental and numerical results is reasonably good. The results show that the bandwidth of the filters appreciably decreases as the tuning frequency increases for frequencies located above the magnetostatic waves range (MWR). However, tuning is achieved without substantial bandwidth reduction for frequencies located below the MWR.