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Temperature Coefficient of Microwave Resonance Frequency of a Low‐Temperature Cofired Ceramic (LTCC) System
Author(s) -
Jantunen Heli,
Uusimäki Antti,
Rautioaho Risto,
Leppävuori Seppo
Publication year - 2002
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2002.tb00153.x
Subject(s) - temperature coefficient , ceramic , materials science , microwave , scanning electron microscope , permittivity , dielectric , relative permittivity , dissipation factor , microstructure , analytical chemistry (journal) , dissipation , resonance (particle physics) , composite material , chemistry , optoelectronics , telecommunications , thermodynamics , physics , chromatography , particle physics , computer science
A family of low‐temperature cofired ceramics (LTCC) based on mixtures of a commercial dielectric, MgTiO 3 –CaTiO 3 (designated MMT‐20) and ZnO, SiO 2 , and B 2 O 3 , has been investigated for microwave applications. The main objective was to optimize the three key properties—relative permittivity (ɛ r ), dissipation factor (DF), and the temperature dependence of the microwave resonance frequency (τ f )—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, B 2 O 3 ; 6.95–7.05, SiO 2 ; and 30–30.5, MMT‐20, yielding values of ɛ r = 8.5–9.5, DF < 0.93 × 10 −3 ppm/K, and τ f < ±10 ppm/K.