Temperature Coefficient of Microwave Resonance Frequency of a Low-Temperature Cofired Ceramic (LTCC) System |
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Authors: | Heli Jantunen Antti Uusimäki Risto Rautioaho Seppo Leppävuori |
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Affiliation: | Microelectronics Laboratory and EMPART Research Group of Infotech Oulu, University of Oulu.;Materials Engineering Laboratory and EMPART Research Group of Infotech Oulu, University of Oulu. |
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Abstract: | A family of low-temperature cofired ceramics (LTCC) based on mixtures of a commercial dielectric, MgTiO3–CaTiO3(designated MMT-20) and ZnO, SiO2, and B2O3, has been investigated for microwave applications. The main objective was to optimize the three key properties—relative permittivity (?r), dissipation factor (DF), and the temperature dependence of the microwave resonance frequency (τf)—through adjustment of the composition. A further objective was to estimate the limits on compositional variability while maintaining acceptable properties. The developed microstructures, after firing at 900°C, were studied using X-ray diffractometry and scanning electron microscopy/energy dispersive spectrometry techniques and compared with the dielectric parameters. The optimum composition (wt%) was found to lie in the ranges 45.8–44.9, ZnO; 17.25–17.55, B2O3; 6.95–7.05, SiO2; and 30–30.5, MMT-20, yielding values of ?r= 8.5–9.5, DF < 0.93 × 10?3 ppm/K, and τf< ±10 ppm/K. |
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Keywords: | low temperature dielectric materials/properties microwaves |
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