2000 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

IEEE Transactions on Microwave Theory and Techniques
Volume 48 Number 2, February 2000

On RF Material Characterization in the Stripline Cavity

Page 266.

Abstract:

We examine the accuracy of the air-filled stripline cavity in measuring the dielectric and magnetic properties of bulk materials in the frequency range of 150-2000 MHz. Measured data on complex permittivity and permeability for several different-sized specimens of dielectric and magnetic materials were compared with reference values obtained using other techniques of known uncertainties. Major differences were noted for both complex permittivity and permeability data, and we largely attribute these to less-than-optimal perturbation of the internal cavity fields by the material specimens under test. The technique is particularly unsuited to measuring the dielectric loss of the higher-permittivity low-loss materials due to energy scatter by the specimen under test. In order to improve measurement accuracy, we suggest guidelines on the range of specimen electric and magnetic volume needed for optimal cavity perturbation.

References

1. R. A. Waldron, "Theory of a strip-line cavity for measurement of dielectric constants and gyromagnetic-Resonance line-widths", IEEE Trans. Microwave Theory Tech., vol. MTT-12, pp.  123 -131, Jan.  1964.
2. S. Maxwell, "A stripline cavity resonator for measurement of ferrites", Microwave J., vol. 9, pp.  99- 102, 1966.
3. R. A. Waldron, "Theory of the strip-line cavity resonator ", Marconi Rev., vol. 27, pp.  30- 42, 1964.
4. S. Maxwell, "Strip-line cavity resonator for measurement of magnetic and dielectric properties of ferrites at low microwave frequencies ", Marconi Rev., vol. 27, pp.  22- 29, 1964.
5. " Standard Test Methods for Complex Permittivity (Dielectric Constant) of Solid Electrical Insulating Materials at Microwave Frequencies and Temperatures to 1650 °C", ASTM Standard D 2520-95, 1998.
6. "Microwave Measurement Systems Services and Products, Catalog #17", Damaskos, Inc., Concordville, PA, Jan. 1998.
7. C. A. Jones, Y. Kantor, J. H. Grosvenor and M. D. Janezic, "Stripline resonator for electromagnetic measurements of materials ", NIST, Boulder, CO, Tech. Note 1505, July 1998.
8. C. A. Jones, "Permeability and permittivity measurements using stripline resonator cavities: A comparison", IEEE Trans. Instrum. Meas., vol. 48, pp.  843-848, Aug.  1999.
9. J. R. Baker-Jarvis, M. D. Janezic, J. H. Grosvenor and R. G. Geyer, "Transmission/reflection and short-circuit line methods for measuring permittivity and permeability", NIST, Boulder, CO, Tech. Note 1355 (revised), Dec. 1993.
10. R. E. Collin, Field Theory of Guided Waves, 2 ed.  : IEEE Press, 1991.
11. C. A. Jones, L. Muth, J. Baker-Jarvis, Y. Kantor, J. DeFord and P. Wallen, "Stripline resonator analysis using finite element codes", in Abstracts Nat. Radio Sci. Meeting, CO, Jan. 3-7 1995.
12. R. A. Waldron and S. P. Maxwell, "Note on the measurement of material properties by the stripline cavity", IEEE Trans. Microwave Theory Tech., vol. MTT-13, p.  711,  Sept.  1965.
13. H. M. Musal, "Demagnetization effect in strip-line cavity measurements", IEEE Trans. Magn., vol. 28, pp.  3129-3131, May  1992.
14. S. L. Browning and E. P. Westbrook, "Stripline cavity design for material characterization", in Proc. AMTA Workshop, July 1992 , pp.  3.1-3.16. 
15. E. C. Stoner, "The demagnetizing factors for ellipsoid", Philos. Mag. Ser., vol. 7, no. 36(263), pp.  803- 821, 1945.
16. Y. Kantor, "Novel approach for demagnetization effect in stripline resonator", Jan. 1995
17. J. Baker-Jarvis, R. G. Geyer, J. H. Grosvenor, Jr., M. D. Janezic, C. A. Jones, B. F. Riddle, C. M. Weil and J. Krupka, "Dielectric Characterization of low-loss materials: A comparison of techniques", IEEE Trans. Dielect. Elect. Insulation, vol. 5, pp.  571- 577, Aug.  1998.
18. C. M. Weil, M. D. Janezic and E. J. Vanzura, "Intercomparison of permeability and permittivity measurements using the Transmission/reflection method in 7 and 14 mm coaxial air lines ", NIST, Boulder, CO, Tech. Note 1386, Mar. 1997.
19. M. L. Crawford, "Generation of standard EM fields using TEM transmission line Cells", IEEE Trans. Electromag. Compat., vol. EMC-10, pp.  189-19 5, Nov.  1974.
20. K. F. Sabet, "A rigorous numerical solution for characterization of low-loss dielectric materials from cavity measurements", EMAG Technol. Inc. , Ann Arbor, MI, Dec. 1995 .