Magnetically tuned Zn2Z filters for the 18-40 GHz frequency range

Magnetically tunable filters operating in the 18-26.5 and 26.5-40 GHz frequency ranges have been constructed with spherical single crystal Ba3Zn2- Fe24O41(Zn2Z) resonators. Substantial reduction in the external magnetic field required for resonance (Ho) has been achieved by making use of the large anisotropy field (Ha) of Zn2Z. The design and performance of two-resonator Zn2Z filters which tune the 18-26.5 and 26.5-40 GHz frequency ranges are described. By using measured values for the saturation magnetization (Ms), Ha, and resonance linewidth (ΔH), the calculated filter 3 dB bandwidth (BW) and loss are 220 MHz and 6.4 dB respectively at 26.5 GHz. Experimentally measured filter performance characteristics reported herein are in substantial agreement with these calculations.