Hi sarah_spike
I am a little confused. On one hand, there are many programs that give or can give results for microstrip line full wave analysis. On the other hand, you don't need the codes for fullwave analysis unless you have to write yourself a program that does the analysis.
I assume you are supposed to write a program and need something to start with. Although I did similar thing using SDA and wrote codes in FORTRAN, it is long time gone now, but I can recommand FORTRAN program printed in the following book:
Tatsuo Itoh –
Numerical Techniques for Microwave and Millimeter-Wave Passive Structures,
John Wiley & Sons, 1989
There is a chapter on spectral domain analysis written by Tomoki Uwano and Tatsuo ltoh himself with one of the appendices for this chapter being a listing of a SDA program code.
Good luck!
flyhigh