The aim of this work is to characterize the electrical conductivity of composite conductors deposited on an alumina substrate. Several half-wavelength coplanar resonators are realized using several pure conductors, silver (Ag), copper (Cu), gold (Au) and tin (Sn), to compare their quality factors (Q0), related to losses, with those from analytical methods. In the literature, losses in coplanar components have been estimated by different analytical methods. We have put in evidence the relationship between electrical conductivity of the conductor and the resonator quality factor. An overall good agreement among quality factor values obtained by the analytical formulas, by numerical simulations and by microwave measurements is observed. The surface roughness is taken into account to better estimate real conductor losses. Therefore, these analytical formulas are used to extract the electrical conductivity values of the composite conductors (Ag-aC, AgSnIn and AgSn), from measured quality factors.
2. Maxwell, E., "Conductivity of metallic surfaces at microwave frequencies," Applied Physics, Vol. 18, No. 2, Jul. 1947.
3. Beilenho, K., et al., "Open and short circuits in coplanar MMIC’s," IEEE Trans. Microwave Theory and Tech., Vol. 41, No. 4, 1534-1537, Sep. 1993.
doi:10.1109/22.245673
4. Holloway, C. L. and E. F. Kuester, "A quasi-closed form expression for the conductor loss of CPW lines, with an investigation of edge shape edge effects," IEEE Trans. Microwave Theory and Tech., Vol. 43, No. 6, 2695-2701, Dec. 1995.
doi:10.1109/22.477846
5. Collin, R. E., Foundations for Microwave Engineering, 2nd Ed., 178-179, McGraw-Hill, New York, 1992.
6. Ghione, G. and C. U. Naldi, "A new analytical, cad-oriented model for the ohmic and radiation losses of asymmetric coplanar lines in hybrid and monolithic MIC’s," Gallium Arsenide Applications Symposium, GAAS, 1992, Noordwijk, Netherlands, Apr. 27-29, 1992.
7. Owyang, G. H. and T. Wu, "The approximate parameters of slot lines and their complement," IRE Transactions on Antennas and Propagation, Vol. 6, No. 1, 49-55, Jan. 2003.
doi:10.1109/TAP.1958.1144556
8. Holloway, C. L. and E. F. Kuester, "A quasi-closed form expression for the conductor loss of CPW lines, with an investigation of edge shape effects," IEEE Trans. Microwave Theory and Tech., Vol. 43, No. 12, 2695-2701, Dec. 1995.
doi:10.1109/22.477846
9. Frankel, Y., et al., "Terahertz attenuation and dispersion characteristics of coplanar transmission lines," IEEE Trans. Microwave Theory and Tech., Vol. 39, No. 1, Jun. 1991.
10. Belohoubek, E. and E. Denlinger, "Loss considerations for microstrip resonators," IEEE Trans. Microwave Theory and Tech., Vol. 23, No. 1, 522-526, Janvier, 2003.
11. Tsang, L., X. Gu, and H. Braunisch, "Effects of random rough surface on absorption by conductors at microwave frequencies," IEEE Microwave and Wireless Components Letters, Vol. 16, No. 4, Apr. 2006.
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