volume | PIER Journals

Abstract

A new technique for broadband material characterization, using a whispering-gallery-mode (WGM) resonator, is proposed. The resonant perturbation method is applied for the measurement of both the dielectric constant and loss tangent of various types of materials and over a wide frequency band. A comprehensive study on the reliability of using such technique, via simulations and measurements, is conducted as well. The feasibility of this device in sensing small variations of the dielectric properties of the material is investigated. Furthermore, the geometry of the resonator is slightly modified to fit liquid materials as well. This can be a promising solution for sensing human-body tissues or liquids such as blood or urine due to the sensitive nature of these resonators. The experimental setup is successfully utilized to measure the dielectric constant of a water droplet as a liquid sample as well as different material samples of arbitrary shapes and dielectric properties. The measurements are performed over the whole X- and K-bands where the obtained results are with a maximum deviation of only 3.3% for solids and 4.5% for liquids.

1. Baker-Jarvis, J., R. G. Geyer, J. H. Grosvenor, Jr., M. D. Janezic, C. A. Jones, B. Riddle, C. M. Weil, and J. Krupka, "Dielectric characterization of low-loss materials: A comparison of techniques," IEEE Trans. on Dielectrics and Electrical Insulation, Vol. 5, No. 4, 571-577, Aug. 1998.
doi:10.1109/94.708274

2. Williams, T., M. A. Stuchly, and P. Saville, "Modified transmission-reflection method for measuring constitutive parameters of thin flexible high-loss materials," IEEE Trans. on Microwave Theory and Tech., Vol. 51, No. 5, 1560-1566 , May 2003.
doi:10.1109/TMTT.2003.810139

3. Ocera, A., M. Dionigi, E. Fratticcioli, and R. Sorrentino, "A novel technique for A complex permittivity measurement based on a planar four-port device," IEEE Trans. on Microwave Theory and Tech., Vol. 54, No. 6, 2568-2575, Jun. 2006.
doi:10.1109/TMTT.2006.872914

4. Kheir, M. S., H. F. Hammad, and A. Omar, "Measurement of the dielectric constant of liquids using a hybrid cavity-ring resonator," PIERS Proceedings, 566-569, Cambridge, USA, Jul. 2008.

5. Chen, L. F., C. K. Ong, C. P. Neo, V. V. Varadan, and V. K. Varadan, Microwave Electronics: Measurement and Material Characterization, John Wiley & Sons Inc., 2004.

6. Cros, D. and P. Guillon, "Whispering gallery dielectric resonator modes for w-band devices," IEEE Trans. on Microwave Theory and Tech., Vol. 38, No. 11, 1667-1674, Nov. 1990.
doi:10.1109/22.60014

7. Jiao, X. H., P. Guillon, L. A. Bermudez, and P. Auxemery, "Whispering-gallery modes of dielectric structures: Applications to millimeter-wave bandstop filters," IEEE Trans. on Microwave Theory and Tech., Vol. 35, No. 12, 1169-1175, Dec. 1987.
doi:10.1109/TMTT.1987.1133834

8. Neshat, M., S. Gigoyan, D. Saeedkia, and S. Safavi-Naeini, "Travelling-wave whispering gallery resonance sensor in millimetre-wave range," Electronics Letters, Vol. 44, No. 17, 1020-1022, Aug. 2008.
doi:10.1049/el:20081445

9. Krupka, J., K. Derzakowski, A. Abramowicz, M. E. Tobar, and R. G. Geyer, "Use of whispering-gallery modes for complex permittivity determinations of ultra-low-loss dielectric materials," IEEE Trans. on Microwave Theory and Tech., Vol. 47, No. 6, 752-759, Jun. 1999.
doi:10.1109/22.769347

10. Krupka, J., D. Mouneyrac, J. G. Hartnett, and M. E. Tobar, "Use of whispering-gallery modes and quasi-TE0np modes for broadband characterization of bulk gallium arsenide and gallium phosphide samples," IEEE Trans. on Microwave Theory and Tech., Vol. 56, No. 5, 1201-1206, May 2008.
doi:10.1109/TMTT.2008.921652

11. Shaforosat, E. N., N. Klein, S. A. Vitusevich, A. Offenhausser, and A. A. Barannik, "Nanoliter liquid characterization by open whispering-gallery mode dielectric resonator at millimeter wave frequencies," Journal of Applied Physics, Vol. 104, No. 7, 1-7, Oct. 2008.

12. Shaforosat, E. N., N. Klein, S. A. Vitusevich, A. A. Barannik, and N. T. Cherpak, "High sensitivity microwave characterization of organic molecule solutions of nanoliter volume," Applied Physics Letters, Vol. 94, No. 11, 1-3, Mar. 2009.

13. Kheir, M. S., H. F. Hammad, and A. Omar, "Non-destructive broadband material characterization over the K-band using whispering-gallery-mode resonators," Proceedings of the 27th Conference on Precision Electromagnetic Measurements (CPEM2010), 285-286, Daejeon, Korea, Jun. 2010.

14. Chen, L., C. K. Ong, and B. T. G. Tan, "Amendment of cavity perturbation method for permittivity measurement of extremely low-loss dielectrics," IEEE Trans. on Instrumentation and Measurement, Vol. 48, No. 6, 1031-1037, Dec. 1999.
doi:10.1109/19.816109

15. Kraszewski, A. W. and S. O. Nelson, "Observations on resonant cavity perturbation by dielectric objects," IEEE Trans. on Microwave Theory and Tech., Vol. 40, No. 1, 151-155, Jan. 1992.
doi:10.1109/22.108334

16. Khanna, A. and Y. Garault, "Determination of loaded, unloaded, and external quality factors of a dielectric resonator coupled to a microstrip line," IEEE Trans. on Microwave Theory and Tech., Vol. 31, No. 3, 261-264, Mar. 1983.
doi:10.1109/TMTT.1983.1131473

17. Kajfez, D. and P. Guillon, electric Resonators, Artech House, Norwood, MA, 1986.

18. Pozar, D. M., Microwave Engineering, 2nd Edition, John Wiley & Sons Inc., 1998.

19. , , , CST Microwave Studio, 2009, http://www.cst.com.

20. Wilkes, C. E., C. A. Daniels, and J. W. Summers, PVC Handbook, Hanser Publications, 2005.
doi:10.1109/TIM.2011.2122170

21. , , , Cuming Microwave Corp., http://www.cumingmw.com.

22. Kheir, M. S., H. F. Hammad, and A. Omar, "Graphical representation and evaluation of attenuation and coupling parameters of whispering-gallery-mode resonators," IEEE Trans. on Instrumentation and Measurement, Vol. 60, No. 8, 2942-2950, Aug. 2011.

Dr. Mohamed Kheir

Professor Hany Fathy Hammad

Prof. Abbas Omar