Health & Environmental Research Online (HERO)


Print Feedback Export to File
1735301 
Journal Article 
Multilayer BST-COC Composite with Enhanced High Frequency Dielectric Properties 
Teirikangas, M; Juuti, J; Jantunen, H 
2009 
Yes 
Ferroelectrics
ISSN: 0015-0193 
387 
210-215 
WOS:000270472600029 
The 0-3 composites with a mixture of randomly dispersed and separated ceramic particles and thermoplastic polymers provide flexible method to fabricate RF devices with adjusted mechanical and electrical properties. However, high ceramic loading levels are required to achieve high relative permittivity which, on the other hand, dramatically degrades the mechanical properties of the composite. In this work vertical and horizontal 2-2 type multilayer structures were fabricated by hot lamination of injection moulded 0-3 BST-COC composite materials with different loading levels of paraelectric ceramic (Ba(0.55)Sr(0.45)Ti(1.01)O(3)). Each layer and the structures with gradient in permittivity and loss were characterized up to 1 GHz by impedance analyzer. The relative permittivity for the vertical and horizontal gradient structure with identical layer order and average ceramic loading of similar to 16 vol.% was 6.54 and 10.60 at 1 GHz, respectively. The results showed that especially the horizontal structure is able to provide higher relative permittivity values than a vertical one with similar ceramic loading levels and with competitive dielectric losses. Since the introduced structure is composed of combination of ductile and brittle layers, it also offers a way to fabricate devices with improved mechanical properties. 
Thermoplastic polymer; composite structure; RF properties