Advertisement

Quasi-optical measurement of complex dielectric constant at 300 GHz

  • Bernd Stöckel
Article

Abstract

A two beam interferometer in the Martin-Puplett configuration is used to determine the complex dielectric constant at 300 GHz of teflon, TPX-plastics, SPECTRALON and paraffin waxes with melting temperatures of 48° C and 72° C, respectively. The design of the quasi-optical system leads to a constant beam diameter at the power detector independent of path delay and frequency. The power detector signal is recorded not only along one period but over about 50 periods. A spectrum estimation routine allows to determine more exactly amplitude and phase angle of the signal. A basic problem is noticed: imperfect detector and source match cause harmonic distortion of the power detector signal. The effects on processing the loss tangent and the invalidation are shown. Finally loss tangent and dielectric constant are determined indirectly by optimizing an equivalent microwave circuit using a commercial available microwave design system to take multiple reflections and losses in consideration.

Keywords

Quasi-optics interferometer dielectric constant loss tangent TPX teflon SPECTRALON paraffin harmonic distortion complex overlap integral 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

9 Literature

  1. [1]
    Simonis, G.J.: Index to the Literature Dealing with the Near-Millimeter Wave Properties of Materials; Intern. Journal of Infrared and Millimeter Waves, Vol. 3, No. 4, 1982, pp. 439–469.Google Scholar
  2. [2]
    Afsar, M.N.: Dielectric Measurements of Millimeter-Wave Materials; IEEE Trans. on Microwave Theory and Techniques, Vol. MTT-32, No. 12, December 1984, pp. 1598–1609.Google Scholar
  3. [3]
    Jones, C.R.; Dutta, J.M.; Davé, H.: Complex Dielectric Constants for Selected Near-Millimeter-Waves Materials at 245 GHz; IEEE Trans. on Microwave Theory and Techniques, Vol. MTT-34, No. 9, September 1986, pp. 932–936.Google Scholar
  4. [4]
    Jones, C.R.; Dutta, J.M.; Davé, H.: Two-Beam Interferometer for Optical Constants Measurements at Near-Millimeter Wavelengths; Intern. Journal of Infrared and Millimeter Waves, Vol. 5, No. 3, 1984, pp. 279–299.Google Scholar
  5. [5]
    Qiu Bingsheng, Liu Chengjia, Huang Jiangjun, Qiu Ruman: Automatic Measurement for Dielectric Properties of Solid Material at 890 GHz; Intern. Journal of Infrared and Millimeter Waves, Vol. 13, No. 6, 1992, pp. 923–931.Google Scholar
  6. [6]
    Martin, D.H.; Puplett, E.: Polarized interferometric spectrometry for the millimetre and submillimetre spectrum; Infrared Physics, Vol. 10, 1969, pp. 105–109.Google Scholar
  7. [7]
    Goldsmith, P.F.: Quasioptical Techniques offer Advantages at Millimeter Frequencies; MSN, December 1983, pp. 65–84.Google Scholar
  8. [8]
    Stöckel, B.: Derivation of Invariant Quasi-Optical Systems and Their Applications — Especially at a mm-Wave-Fourier-Transform Spectrometer; Vol. AEÜ-44, No. 4, 1990, pp. 306–312.Google Scholar
  9. [9]
    Kogelnik, H.: Coupling and Conversion Coefficients for Optical Modes; Proceedings of the Symposium on Quasi-Optics, New York, June 8–10, 1964, pp. 333 – 347.Google Scholar
  10. [10]
    Chantry, G.W.: Submillimetre Spectroscopy; Academic Press, London and New York, 1971.Google Scholar
  11. [11]
    Jongbloets, H.W.; Van de Steeg, M.; Van der Werf, E.J.; Stoelinga, J.H. and Wyder, P.: Spectrum distortion in far-infrared Fourier spectrometry by multiple reflections between sample and Michelson interferometer; Vol. 20, Infrared Physics, 1980, pp. 185–192.Google Scholar
  12. [12]
    Chamberlain, J.: The principles of interferometric spectroscopy; Wiley, Chichester, 1979.Google Scholar
  13. [13]
    Schneider, R.: Aufbau eines Autokorrelators zur Verwendung als Spektral-Analysator bei Submillimeter-Wellen; Diploma-Thesis, No. 526, 1989, Lehrstuhl für Hochfrequenztechnik, Universität Erlangen-Nürnberg.Google Scholar
  14. [14]
    Höß H.: Parametrische Schätzung von Frequenzen und Amplituden von Mehrtonsignalen; Diploma Thesis No. XE-417, 1992, Lehrstuhl für Nachrichtentechnik, Universität Erlangen-Nürnberg.Google Scholar
  15. [15]
    Martin, U.: Private Communications; Lehrstuhl für Nachrichtentechnik, Universität Erlangen-Nürnberg, 1992.Google Scholar
  16. [16]
    Hua, Y.; Sarkar, T.K.: Matrix pencil method for estimating parameters of exponentially damped/undamped sinusoids in noise; IEEE Trans. Acoust., Speech Signal Process., May 1990.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Bernd Stöckel
    • 1
  1. 1.Lehrstuhl für HochfrequenztechnikUniversität Erlangen-NürnbergErlangenGermany

Personalised recommendations