Wide Microstrip Line Type Probe With Slits and Permeability Evaluation of Thick Magnetic Material

We have developed a new microstrip line type probe with a wide conductor having some slits to eliminate the measurement error of the demagnetizing effect in thick samples. The slits enhanced the homogeneity of the high-frequency current in the wide direction of the microstrip conductor, which resulted in the application of a uniform high-frequency magnetic field to the sample. Complex relative permeability of thick NiZn ferrite sheet and carbonyl iron particle (CIP) sheet (
$3\times $
1 mm,
$100 ~\mu \text{m}$
in thickness) has been evaluated accurately using the probe. The measurement error of permeability was evaluated within about 15% in 0.1–20 GHz compared with the conventional Nicolson–Ross–Weir method.