Development of Patch Antenna Substrate in BaO-4.TiO2 System
| Autor: | B. Masin, Mariamma Mathew, H. Sreemoolanadhan, S.C. Sharma |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Mechanical Engineering Sintering Mineralogy Substrate (electronics) Dielectric Condensed Matter Physics Microstructure Grain growth Mechanics of Materials visual_art visual_art.visual_art_medium General Materials Science Ceramic Composite material Temperature coefficient Phase diagram |
| Zdroj: | Materials Science Forum. :425-428 |
| ISSN: | 1662-9752 |
| DOI: | 10.4028/www.scientific.net/msf.830-831.425 |
| Popis: | BaTi4O9(BT4), has dielectric constant (εr)≈36 and unloaded Q-factor (Qf) >35,000GHz, but has temperature coefficient of frequency (τf~16-20ppm/°C). Ba2Ti9O20(B2T9), very near to BT4 in the BaO-TiO2phase diagram, has εr~38, Qf~35,000GHz and τf3added BaTi4O9ceramics are reported. The ceramics have been prepared by the solid state method. Raw materials have been homogenized and calcined at 1125°C. Calcined powders are ball-milled, compacted and sintered in 1275−1350°C to get dense ceramics with ρ=4.38-4.44 g/cc (TD>97.5%). XRD analysis has confirmed the BaTi4O9phase formation along with secondary phases. FeSEM microstructures show liquid phase assisted sintering leading to fused grains and exaggerated grain growth. The dielectric properties have been measured near 4GHz by standard rod resonator methods using cylindrical specimens. The ceramics have εr36.5−38, τf17THz. It is possible to further improve the Qf of these ceramics by controlling the processing. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|