28 GHz band bandpass filter using high Q dielectric resonators

The high-Q dielectric ceramic Ba(Sn,Mg,Ta)O/sub 3/ was applied to a symmetrically circular filter of a novel configuration. Direct eigenmode expansion was applied to multipole bandpass filter design and was found to be effective for determination of the construction parameters. The overall size of the filter is 10 mm*10 mm*20 mm, and the volume is one fourth that of dielectric resonator filters of conventional parallel structure. The insertion loss of the filter is 0.74 dB at 190 MHz bandwidth, and attenuation is 33 dB at f/sub 0/+or-300 MHz. The filter is suitable for K-band communication equipment.<
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