The closed cavity method is proposed to measure the frequency temperature coefficient (τf) of a dielectric resonator. The τf polynomial, which is linear combination of the temperature coefficient of relative dielectric constant and the linear expansion coefficient of the dielectric and cavity, is given. The coefficients of τf polynomial are discussed in detail. The intrinsic temperature coefficient of resonant frequency (τf0) is introduced to improve the measurement precision. Resonators made of BaO-TiO2-Sm2O3 and (Zr0.8Ti0.2)TiO4 ceramics with Teflon and alumina as supports were measured. The results show that the τf values of the same resonator with above supports are different, and the measured variation between them is more than 3 ppm/˚C. Using the concept of τf0, the variation is less than 2 ppm/˚C.
2. Kobayashi, Y., Y. Kogami, and M. Katoh, "A method of evaluating the temperature dependence of dielectric resonators and materials," Proc. of 23th European Microwave Conference, 562-563, Sep. 1993.
3. Abramowicz, A. and J. Modelski, "Accurate method of measuring the temperature coefficients of dielectric resonator materials," 21st European Microwave Conference, 1391-1396, 1991.
4. Nishikawa, T., K. Wakino, H. Tamura, H. Tanaka, and Y. Ishikawa, "Precise measurement method for temperature of dielectric resonator material," IEEE MTT-S Int. Microwave Symp. Digest, No. J-6, 277-280, 1987.
5. Nikawa, Y. and Y. Guan, "Dynamic measurement of temperature dependent complex permittivity of material by microwave heating using cylindrical cavity resonator," Proceedings of Asia-Pacific Microwave Conference, 1-4, 2007.
6. Tobar, M. E., G. L. Hamilton, J. G. Hartnett, E. N. Ivanov, D. Cros, and P. Guillon, "Accurate characterization of the temperature coefficients of permittivity of sapphire utilizing the dual-mode frequency locked technique," Proceedings of the 2003 IEEE International Frequency Control Symposium, 365-370, 2013.
7. Silva, M. A. S., T. S. M. Fernandes, and A. S. B. Sombra, "An alternative method for the measurement of the microwave temperature coefficient of resonant frequency (τf)," Journal of Applied Physics, Vol. 112, 074106-1-7, 2012.
8. Krupka, J., "Resonant modes in shielded cylindrical ferrite and single-crystal dielectric resonators," IEEE Transactions on Microwave Theory and Techniques, Vol. 37, 691-697, 1989.
doi:10.1109/22.18841
9. Sheen, J., "Microwave measurements of dielectric properties using a closed cylindrical cavity dielectric resonator," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 14, No. 5, 1139-1144, 2007.
doi:10.1109/TDEI.2007.4339473
10. Kafjez, D. and P. Guillon, Dielectric Resonators, Artech House, 1986.
Submit
