Extension and error analysis of the microstrip transmission-line method for the broad-band measurement of the permeability tensor

In this paper, the theory associated with a noniterative and broad-band method for measuring the permeability tensor components μ=μ´-jμ´´ and κ=κ´-jκ´´ is extended in order to simultaneously determine the test sample-relative permittivity ε=ε´-jε´´. The error sources of the method are equally presented and quantified. Detailed theoretical and experimental studies are performed to estimate the errors in the determination of μ, κ, and ε due to the quasi-static approximation for their calculation, as well as the uncertainty in the measured S-parameters of the test cell and samples length. These define the frequency-validity domain of the method.