Glass-ceramics as dielectrics for anntenas in microwave electronics

This paper presents a new alternative technology to conventional ceramic techniques for the fabrication of compact and efficient microwave components like antennas and filters. It uses glass-ceramics as dielectrics which can be casted to net shape in their glassy phase and which can be crystallized afterwards. The resulting pore-free bulk materials exhibit high homogeneity and surface smoothness, while keeping high permittivity, low dielectric loss and low temperature coefficient. In this paper, for the first time a glass-ceramic has been implemented in dielectric loaded antennas for GPS application. The Ba-Ti-Al-Si-O material system exhibits ε_r=33 and Qf=10000 GHz. Characterizations of fully functional GPS antenna have confirmed its advantage in miniaturization and radiation efficiency.