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.