COMPUTER CONTROLLED SYSTEM FOR COMPLEX PERMEABILITY MEASUREMENT IN THE FREQUENCY RANGE OF 5 Hz - 1 GHz

Rastislav Dosoudil – Elemír Ušák – Vladimír Olah

   Two different methods have been used to determine the complex permeability over the frequency range 5 Hz to 1 GHz of several toroidal-shaped spinel ferrite samples. Automated measurements are obtained by means of two different computer controlled analyzers. At low frequencies (5 Hz - 10 MHz), an inductance measurement method is used. A simple method was used to eliminate the coil effects from the sample response. At high frequencies (1 MHz - 1 GHz), a coaxial transmission line measurement method has been used. The operation principle as well as calibration and compensation procedures for both the analyzers are discussed. Measurements are optimised by the partial elimination of undesirable influences. For computer control and measurement process, two different programs have been written in the VEE environment (Agilent technology).

Keywords: complex permeability, sintered ferrite, low-capacitance winding, coaxial line cell, impedance, reflection coefficient

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