Design of coaxial aircell fixture for the measurement of electromagnetic properties

Seetha Rama Raju Vengala Raju

Abstract


Coaxial aircells are designed and fabricated to measure the electromagnetic properties of ferrite materials in the frequency range from 1 MHz to 3.6 GHz. The S-parameters are measured connecting the aircell to a vector network analyzer (VNA). The electromagnetic properties such as complex permittivity and complex permeability are extracted using Nicolson-Ross-Weir (NRW) method and suitable air-gap corrections are made. For the optimization of the measured result and to estimate the error, the aircells are characterized in terms of their phase constant and resistivity of the aircell conductor. The measurements show that the electrical length is longer than the mechanical length of the aircell at all frequencies. The arithmetic mean of the resistivity of aircell of 7mm line size of length of 60 mm is about 66 nΩm. This paper presents a simple method whereby the phase constant and resistivity of the aircell can be determined accurately using transmission measurements made using a VNA.


Keywords


Coaxial aircell, S-parameters, Complex permittivity, Complex permeability

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References


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DOI: http://dx.doi.org/10.1590/2179-10742017v16i3908

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