Journal directory listing - Volume 31-41 (1986-1996) - Volume 41 (1996)

Synthesized Crystal Structure and Microwave Characteristics in Bandpass Filter of Dielectric Resonator Ba2Ti9O20 Ceramics Author: Hsiu-Fung Cheng(Department of Physics, National Taiwan Normal University)


An evanescent bandpass filter with resonance frequency f0=5.10 GHz and band width Δf =0.0345 GHz has been designed for testing the feasibility of using Ba2Ti9O20 materials as dielectric resonators. The width of the rectangular cavity was found to af-fect the cutoff frequency of the device most significantly, while the length of the cavity has least influence. The insertion of the dielectrics, on the other hand, lowers the cutoff frequency. The center frequency of the passing band is the same as the resonance fre-quency of the dielectric resonators. As to the synthesis of the materials for dielectric resonators, i.e., Ba2Ti9O20, the sprayed pyrolysis of metallo-organic precursors was found superior to coprecipitation process. The formation of intermediate phases, i.e. BaTi4O9, BaTi5O11, found in coprecipitation process can be completely eliminated by sprayed pyrolysis technique.

Keywords:Microwave bandpass filter, Dielectric resonator, Ba2Ti9O20

《Full Text》