volume | PIER Journals

Abstract

A matched triaxial device is designed and constructed to measure the transfer impedance of braided coaxial cables at UHF frequencies. Full design principles of the device have been theoretically developed and the details were given in the paper. The device is particularly suited for accurate measurements of transfer impedances at higher radio frequencies up to 3.8 GHz, for which no comparable technique exists. The performance of the device is evaluated by comparing the results against those obtained from low frequency IEC's triple coaxial apparatus and those obtained by using well known theoretical models.

1. IEC PUBLICATIONS 96.1 "Screening efficiency," IEC working group doc, No. SE22/A/WG5, 1967. Google Scholar

2. Fowler, E. P., "Test rings for ZT measurements at high frequency," IEC Working Group document, No. SC46/A/WGl (Fowler 2), 1973. Google Scholar

3. Martin, A. R. and M. Mendenhall, "A fast accurate and sensitive method for measuring surface transfer impedance," IEEE Trans., Vol. EMC-26, 66-70, 1980. Google Scholar

4. Madle, P. J., "Contact resistances and porpoising effects in braided shields," IEEE Trans., Vol. EMC-23, No. 1, 231-236, 1980. Google Scholar

5. Goldberg, J. L. and R. J. Slaugther, "Braid construction and attenuation of coaxial cables at microwave frequencies," Proc. IEE, Vol. 113, No. 6, 384-389, 1966.

6. Sali, S., "Coupling problems in a system of multicoaxial cables in homogeneous and inhomogeneous medium," Ph.D. Thesis, No. 10, 1982. Google Scholar

7. Tyni, M., "The transfer impedance of coaxial cables with braided conductors," EMC Symposium, 22-24, 1976.

8. Bayrak, M. and F. A. Benson, "Intermodulation products from nonlinearities in transmission lines at microwave frequencies," Proc. IEE, Vol. 122, No. 4, 361-367, 1975.

9. Sali, S., "Screening efficiency of triaxial cables with optimum braided shields," IEEE Trans., Vol. EMC-42, No. 8, 26-33, 1991. Google Scholar

10. Kraus, A., "Reflection coefficient curves of compensated discontinuities on coaxial line and determination of optimum dimensions-Part II," Journal of British Inst. of Radio Eng., Vol. 5, No. 5, 365-372, 1962. Google Scholar

11. Fowler, E. P., ''Observations on the use of ZT(C) for comparing the breakthrough capacitance of cable braids, No. '' IEC Working Group document SC46/A/WG1 (Fowler 3), '' IEC Working Group document No. SC46/A/WG1 (Fowler 3), 1973.

12. Homann, E., "Geschirmte kabel mit optimalen geflectschirmen," Nachrichtentechnishe Zeitschrift, Vol. 21, No. 3, 155-161, 1968. Google Scholar

13. Schelkunoff, S. A., "The electromagnetic theory of coaxial transmission lines and cylindrical shields," Bell System Technical Journal, Vol. 13, No. 4, 532-578, 1934. Google Scholar

Dr. S. Sali