Materials Measurement Phil Bartley Shelley Begley

Transmission (Fast) Model• This technique minimizes the difference between themeasured and calculated values of S 21.. The sample isassumed to be non-magnetic.• Often converges to a solution when the NIST model fails.This is because it doesn’t depend on S 11 . The error inmeasuring S 11 is often a order of magnitude worst than whenmeasuring S 21 .The transmission model is based on minimizing the difference between the measuredvalue of the transmission coefficient and the computed value. It assumes that thematerial is non-magnetic. It is an iterative method that starts with an initial guess forpermittivity (usually 1+j0) and improves the guess until the difference is near zero.42