SrTiO₃‐Filled PTFE Composite Laminates for Microwave Substrate Applications

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.

Preparation, Characterization, and Dielectric Properties of PP/CaTiO3 Composites for Microwave Substrate Applications

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Microwave dielectric properties of flexible butyl rubber–strontium cerium titanate composites

“…This relation is suitable for very low volume fraction of ceramic particles. For higher particle loading, there is reduction in depolarization of fillers and increase in relative permittivity, which are not accounted for in this formula 31. The most widely used relation for the prediction of ε r is Lichtenecker's logarithmic law of mixing.…”

Dielectric properties of modified SrTiO3/PTFE composites for microwave RF antenna applications

“…Figure 3 shows the measured and calculated values of the bulk density of PTFE/SrTiO 3 composites with various volume fractions of SrTiO 3 . The calculated values of the bulk density of composites, q cal , are obtained via the asfollowing equation [16]:…”