DESIGN OF COAXIAL AIRCELL FIXTURE FOR THE MEASUREMENT OF ELECTROMAGNETIC PROPERTIES
Keywords:Coaxial aircell, S-parameters, Complex permittivity, Complex permeability
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 nâ„¦m. 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.
dielectric constants and loss tangents at microwave frequencies,” IEEE Trans. Instrum. Meas., vol. 38,
pp. 789-793, 1989.
 P. Skocik, P. Neumann, “Measurement of Complex Permittivity in Free Space,” Procedia Eng.,
vol. 100, pp. 100-104, 2015.
 F. C. Smith, B. Chambers, and J. C. Benett, “Methodology for accurate free-space characterization
of radar absorbing materials,” Proc. Inst. Elect. Eng. Sci. Meas. Technol., vol. 141, pp. 538-546, 1994.
 M. J. Akhtar , L. Feher, M. Thumm, “Measurement of dielectric constant and loss tangent of
epoxy resins using a waveguide approach,” in Proc. IEEE Antennas Propag. Soc. Int. Symp., vol. 1,
pp. 3179 – 3182, 2006.
 H. Soleimania, Z. Abbasb, N. Yahyaa, H. Soleimanib, M. Yeganeh Ghotbic, “Determination of
complex permittivity and permeability of lanthanum iron garnet filled PVDF-polymer composite
using rectangular waveguide and Nicholson–Ross–Weir (NRW) method at X-band frequencies,”
Measurement., vol. 45, pp. 1621-1625, 2012.
 B. Filali, F. Boone, J. Rhazi, G. Ballivy, “Design and Calibration of a Large Open-Ended Coaxial
Probe for the Measurement of the Dielectric Properties of Concrete,” IEEE Trans. Microw. Theory
Tech., vol. 56, pp. 2322-2328, 2008.
 D. M. Hagl, D. Popovic, S. C. Hagness, J. H. Booske, M. Okoniewski, “Sensing Volume of
Open-Ended Coaxial Probes for Dielectric Characterization of Breast Tissue at Microwave
Frequencies,” IEEE Trans. Microw. Theory Tech., vol. 51, pp. 1194-1206, 2003.
 J. Sheen, “Microwave Measurements of Dielectric Properties Using a Closed Cylindrical Cavity
Dielectric Resonator,” IEEE Trans. Dielectr. Electr. Insul., vol. 14, pp. 1139-1144, 2007.
 J. Krupka, A. P. Gregory, O. C. Rochard, R. N. Clarke, B. Riddle, J. B. Jarvis, “Uncertainty of
complex permittivity measurements by split-post dielectric resonator technique,” J. Eur. Ceram. Soc.,
vol. 21, pp. 2673-2676, 2001.
 V. Shemelin, N. Valles, “Improved accuracy of measurements of complex permittivity and
permeability using transmission lines,” Nucl. Instr. Meth. Phys. Res. A., vol. 767, pp. 385-396, 2014.
 J. B. Jarvis, R. Geyer, P. Domich, “Improvements in transmission line permittivity and
permeability measurements,” in Precision Electromagnetic Measurements (CPEM) Conf. on Jun
1990, pp. 232-233.
 J. Xu, M. Y. Koledintseva, Y. Zhang, Y. He, B. Matlin, R. E. DuBroff, J. L. Drewniak, J. Zhang,
“Complex Permittivity and Permeability Measurements and Finite-Difference Time-Domain
Simulation of Ferrite Materials,” IEEE Trans. Electromagn. Compat., vol. 52, pp. 878-887, 2010.
 B. O. Weinschel, “Air-filled coaxial lines as absolute impedance standards,” Microw. J., vol. 7,
pp. 47-50, 1964.
 I. A. Harris, R. E. Spinney, “The realization of high-frequency impedance standards using air
spaced coaxial lines,” IEEE Trans. Instrum. Meas., vol. 13, pp. 265-272, 1964.
 K. H. Wong, “Using precision coaxial air dielectric transmission lines as calibration and
verification standards,” Microw. J., vol. 31, pp. 83-92, 1998.
 G. J. Kilby, N. M. Ridler, “Comparison of theoretical and measured values for attenuation of
precision coaxial lines,” Electron. Lett., vol. 28, pp. 1992-1994, 1992.
 A. M. Nicolson and G. F. Ross, “Measurement of the intrinsic properties of materials by timedomain techniques,” IEEE Trans. Instrum. Meas. vol. 19, pp. 377-382, 1970.
 W. B. Weir, “Automatic measurement of complex dielectric constant and permeability at
microwave frequencies,” Proc. IEEE., vol. 62, pp. 33-36, 1974.
 J. Baker-Jarvis, C. Jones, B. Riddle, M. Janezic, R. Geyer, J. Grosvenor and C. Weil, “Dielectric
and magnetic measurements: A survey of nondestructive, quasinondestructive, and process- control
techniques,” Research in Nondestructive Evaluation, vol. 7, pp. 117-136, 1995.
 J. Krupka, A. Abramowicz, “Measurements of Electromagnetic Properties of Materials at
Microwave Frequencies,” XXXII International Conference of IMAPS - CPMT IEEE Poland Pułtusk
21 - 24 September 2008.
 J. Baker-Jarvis, “Transmission/Refection and Short-Circuit Line Permittivity Measurements,”
NIST Technical Note 1341, July 1990.
 C.A. Stergioun , V. Zaspalis, “Analysis of the complex permeability of NiCuZn ferrites up to 1
GHz with regard to Cu content and sintering temperature,” Ceram. Int., vol. 40, pp, 357–366, 2014.
 T. Nakamura, “Snoek’s limit in high-frequency permeability of polycrystalline Ni–Zn, Mg–Zn,
and Ni–Zn–Cu spinel ferrites,” J. Appl. Phys., vol. 88, pp. 348-354, 2000.
 S. Zaima, T. Furuta, and Y. Yasuda, “ Conduction mechanism of leakage current in Ta2O5 films
on Si prepared by LPCVD,” J. Electrochem. Soc., vol. 137, pp. 2876-2882, 1990.
 V. Seetha Rama Raju, “Effect of Ta2O5 addition on the electrical and magnetic properties of
nanocrystalline MgCuZn ferrites,” J. Mater. Res., vol. 29, pp. 2220-2228, 2014.
 C. G. Koops, “On the Dispersion of Resistivity and Dielectric Constant of Some Semiconductors
at Audio frequencies,” Phys. Rev. Lett., vol. 83, pp. 121-124, 1951.
 V. Seetha Rama Raju, “Complex permeability spectra of PbO and Ta2O5 added nanocrystalline
MgCuZn ferrites,” J. Magn. Magn. Mater., vol. 382, pp. 84-87, 2015.
 T. Krishnaveni, B. Rajini Kanth, V. Seetha Rama Raju, S. R. Murthy, “Fabrication of multilayer
chip inductors using Ni–Cu–Zn ferrites,” J. Alloys Compd., vol. 414, pp. 282-286, 2006.
 T. Slatineanua, A. R. Iordana, V. Oanceaa, M. N. Palamarua, I. Dumitrub, C. P. Constantinb, O.
F. Caltun, “Magnetic and dielectric properties of Co–Zn ferrite,” Mater. Sci. Eng. B., vol. 178, pp.