| The third generation mobile communication system figured of high speed digital transmission and image transmission requires better performance of communication equipments. And it will generate a new revolution in mobile communication terminal. As the standards of 3G , WCDMA, CDMA2000 and TD-SCDMA were approved by ITU. These standards will be compatible with the second generation mobile communication system and work on the basis of the second. Therefore, the mobile communication terminal should work on the condition of multi-mode and multi-frequency. The research level of the mobiles mentioned above decided by the advanced components such as antennas and fileters which are the keypoints of the front-end RF components. The conventional design concept of front-end RF components can not fulfil the requirements of 3G components. Multilayer structure design based on LTCC technology provided a solution for advanced RF components such as 3G antennas and filters. The key technology of LTCC was the research on low temperature firing microwave dielectric ceramic which can cofire with silver electrode. Thus the research were developed all over the world. Presently, some systems of the ceramic has been investigated deeply and obtained some breakthrough. However, it was disjunct among material properties, components design and preparation technics. Most of the materials had various problems such as difficult to prepare stable slurry or reacting with silver electrode. Few low temperature firing microwave dielectric ceramics can put into practice. Since the restriction of materials and the high request of the design and manufacture technology in muti layer structure, the development of multilayer laminated microwave components were confined. It can not fulfil the requirement of development in mobile communication technology.The research mode that Combined material properties, components design and preparation technics was adopted for the first time and the microwave dielectric ceramic and the corresponding components were developed in this paper.According to their sintering characteristics and dielectric properties.ceramic systems of Ca[(Li,/3Nb2/3), TiJOjXCLNT for short), ZnO-Nb2O5-TiO2(ZNT for short), ZnO-TiO2(ZT for short), Li2O-Nb2O5-TiO2(LNT for short) were selected as the research objects Based on the wetting characteristics between sintering aids and the basis materials and the requirements of multilayer components on slurry property and cofiring of ceramic and silver electrode, the sintering aids and preparation processes were optimized; several kinds of low temperature firing microwave dielectric ceramics which had excellent properties and application value were acquired. (1) Low temperature sintering ceramic CLNT was prepared with multiple additions of ZnO,Bi2O3 and ZnO-B2O3-SiO2 glass(ZBS glass for short). It acquired microwave dielectric properties of r=37.8, Q ?f=11000GHz, r/=12 10~VC sintered at 920 . (2)The ZNT ceramic dielectric properties was modificated by main constituent TiO2,modifying agent SnO2, and sintering aids and its sintering temperature decreased by CuO, V2O5 addition. It acquired microwave dielectric properties of e r=42.3, Q ?f=9000GHz, 77=8 x 10"6/ sintered at 860 . (3) The low temperature sintering ZT ceramic was prepared with ZnO-B2O3-SiO2 doped by sol-gel method for the first time. It acquired microwave dielectric properties of e r=27.05, Q -f=20000GHz, r/=8 IQsintered at 9001). (4) The LNT ceramic sintering temperature decreased and dielectric properties were modificated by V2Os and ZBS glass. It acquired microwave dielectric properties of e r=57, Q ?f=4420GHz, ry=3 x lO"6/ sintered at 900 . All the ceramic systems mentioned above realized a series of low temperature microwave dielectric ceramic, could prepare stable slurry, had a good interface bonding condition with silver electrode and meet the demand of multilayer microwave frequency components of the diffement frenquency.The wetting mechanism of liquid phase low temperature sintering was illustrated according to the low tempe...
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