Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-27T01:47:34.786Z Has data issue: false hasContentIssue false

New High Temperature Multipurpose Applicator

Published online by Cambridge University Press:  28 February 2011

W.R. Tinga
Affiliation:
Electrical Engineering Dept., University of Alberta, Edmonton, Alberta, Canada, T6G 2G7
B.Q. Tian
Affiliation:
Electrical Engineering Dept., University of Alberta, Edmonton, Alberta, Canada, T6G 2G7
W.A.G. Voss
Affiliation:
Electrical Engineering Dept., University of Alberta, Edmonton, Alberta, Canada, T6G 2G7
Get access

Abstract

Using a new microwave small-sample quasi-TEM mode applicator, heating rates up to 700°C/s were obtained for various oxides and ceramic materials at 915 MHz. Design details are presented. A 60 W solid state power source is used to supply the microwave energy and control material temperature. Temperature is measured using either infrared or thermocouple techniques. The applicator is a TEM resonator with a TM mode gap field modified by a hollow variable radius center conductor acting as a waveguide below or near cutoff. This design creates a microwave materials analyzer equally suited for high or low temperature material studies, is scaleable to different frequencies and can be used to measure dielectric properties up to a temperature of at least 1500°C. Solid, granular, liquid, gas or plasma samples can be accommodated. By using microwave transparent refractory materials around the sample, temperatures greater than 15000 C can be maintained in some materials. Perturbation of the resonator by the inserted material causes a frequency shift which is nearly linear over a permittivity range of at least 1–70. This is an order of magnitude improvement over the conventional perturbation approach. For microwave joining or sintering of ceramic rods, the energy can be concentrated into a symmetrical hot zone as narrow as 1 mm.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Couderc, D., Giroux, M. and Bosisio, R.G., J. Of Microwave Power, 8 (1), 6982, 1973.Google Scholar
2. Araneta, J.C., M.E.Brodwin and Kriegsmann, G.E., IEEE Trans. MTT 32 (10), 13281335, 1984.Google Scholar
3. Bernard, P., Marzat, C. and Miane, J., J. of Microwave Power and Electromagnetic Energy, 23 (4), 218224 (1988).Google Scholar
4. Xi, W., Dept. of Electrical Engineering, Univ. of Alberta, Canada, Internal Report #RP90-Xl, 1990 (unpublished).Google Scholar
5. Collin, R.E., Foundations of Microwave Engineering, (McGraw-Hill, New York, 1966).Google Scholar
6. VanKoughnett, A.L. and Wyslouzil, W., J. of Microwave Power, 6 (1), 2530, 1971.Google Scholar
7. Wyslouzil, W. and VanKoughnett, A.L., J. of Microwave Power, 8 (1), 89101, 1973.Google Scholar
8. Tian, B.Q., Dept. of Electrical Engineering, Univ. of Alberta, Canada, Internal Report #RP90-TI, 1990 (unpublished).Google Scholar
9. Hutcheon, R.M., Jong, M.S. de, Adams, F.P., Hunt, L., Iglesias, F., Wood, G.W., and Parkinson, G., Electromagnetic Energy Reviews, 2, (4), 4651, 1989.Google Scholar