Electrical & Electronics Standards, National Physical Laboratory Dr. K. S. Krishnan Road, New Delhi-110012. E-mail: kpatel@nplindia.org
Online published on 10 August, 2015.
Complex permittivity of flexible polyurethane foam and rigid polyethylene foam are determined by the free space transmission method in 8.2–12.4 GHz frequency range. The calculated dielectric constant were found in the range of 1.011 to 1.075 and 1.004 to 1.032 for the polyurethane foam and polyethylene foam respectively, whereas the loss tangents are in the range of 2.33 x 10−3 to 0.04 x 10−2 and 3.65 x 10−4 to 2.77 x 10−2. The results along with their combined uncertainty may be treated as a standard data for the applications of these easily available foams in the microwave frequency range. To establish the reliability, a traceability link of these dielectric property measurements is also presented through the S-parameters measurements, frequency and dimensional metrology.
Dielectric property, material sheet, measurement uncertainty, calibration, free-space method, traceability, Vector network analyzer
