Materials Measurement Phil Bartley Shelley Begley

NIST Model• Technique uses all four measured s-parameters to calculatepermittivity. This eliminates the need to know the position ofthe sample in the sample holder. The sample is assumed tobe non-magnetic.• Sometimes has a problem converging to an answer whenthe measurement errors in S 11 and S 22 is large.J. Baker-Jarvis, E. Vanzura, W. Kissick. “Improved Technique for Determining ComplexPermittivity with the Transmission/Reflection Method.” IEEE Transactions on MicrowaveTheory and Techniques, vol 38, no. 8, pp. 1096-1103, August 1990.The NIST model was developed by Jim Baker-Jarvis of NIST (and others). It uses allfour measured s-parameters to determine permittivity. The material is assumed to benon-magnetic. It is an iterative approach and sometimes has problems convergingwhen the measurement errors in S 11 and S 22 are large.40