Ferrite-tuned filter

In this paper ferrite-tuned filter designs are described. The YIG sphere and design parameters are described also. This filter covered the frequency range 250 to 800 MHz. The insertion loss was 8 dB with off-resonance isolation of 75 dB. The /spl Delta/f/sub 3dB/ is greater than 5 MHz. The temperature operating range is -40 to +70/spl deg/C.