NEC-LIST: microstrip transmission lines

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.

I only need moderate accuracy through the VHF bands so some of the
more esoteric terms are probably not required.

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").

Primary variables are of course the 1) trace width and 2) the height
above the ground plane with air for the dielectric on one side and 3)
the thickness (and dielectric constant) of the G-10 pcb on the "back
side" (and then more air), and 4) the copper trace thickness.

If anyone has any good references on this configuration or a formula I
would certainly appreciate it.

Thanks in advance for any help.

John Brosnahan

La Salle Research Corp
24115 County Road 40
La Salle, CO 80645

970-284-6602
970-284-0979 (fax)
Received on Fri Feb 13 1998 - 04:41:15 EST