>I am looking for a formula for calculating the impedance of
>a microstrip transmission line in an arrangement that does
>not seem to be covered by any of my references.
>The configuration is that of a single sided (ie, no pcb ground
>plane) G-10 circuit board with the transmission line trace
>etched on the side towards the grounded chassis and with
>an air gap between the trace and the chassis ("ground").
>If anyone has any good references on this configuration
>or a formula I would certainly appreciate it.
HP MDS has this configuration available for simulation. They call it
a suspended substrate.
If you are looking for a particular configuration, I can probably help.
The help manual for this component does not list equations, but does
cite the following reference:
J.I. Smith, "The even- and odd-mode capacitance parameters for coupled
lines in suspended substrate", IEEE Trans. Microwave Theory Tech.,
vol. MTT-19, no. 5, pp. 424-431, May 1971.
Chad Kurszewski, WE9V e-mail: Chad_Kurszewski@csg.mot.com
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