SrTiO3-Filled PTFE Composite Laminates for Microwave Substrate Applications

Volume 6 Issue 5, Pages 553 – 561

Surendran Rajesh, Kodakkattu Purushothaman Murali, Kunnathodi
Vijayaraghavan Rajani, Ravendran Ratheesh
Published Online: May 26
2009 5:03PM

DOI: 10.1111/j.1744-7402.2009.02389.x

ABSTRACT
Strontium titanate (SrTiO₃) filled
polytetrafluroethylene (PTFE) substrates were fabricated through sigma
mixing (SM), extrusion (E), calendering (C) followed by hotpressing (H)
(SMECH) process. The filler dispersion in the polymer matrix and the
surface morphology were studied using scanning electron microscopic
(SEM) technique. The permittivity (ɛ’_r) and loss
tangent (tan δ) of the composites were measured using precision
impedance and vector network analyzers. The experimental permittivity of
filled composites was compared with theoretically predicted values.
Dimensionally stable substrate having a permittivity of 13.1 and a loss
tangent of 0.0055 at X-band was prepared in the PTFE/SrTiO₃
composite system.

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