I'm doing some EM simulations on the GHz range for some transmission lines on semiconductor substrates and I'm struggling with something.
For just a bit more context, the structures are often some metal tracks on top of some micrometer-thick doped or undoped semiconductor layers. The problem I have with this is that the most common approach is to simulate using a full 3D solver for the structure, such as CST studio. However, these structures are invariant on the propagation axis, and the modes are oftentimes quasi-TEM, therefore a RLGC transmission line model should be good enough provided we know characteristic impedance and propagation constant of the input modes. Thus, it should suffice to do only a 2D mode finding solver on a cross section and go analytical after that.
The problem is:I can't figure out how to get CST how to do find that information alone. When doing a full 3D sim on CST with waveguide ports the software does compute the modes for each port at the various frequencies, which is exactly what I want, but I want it to stop there and not propagate anything, and find the modes' properties for the various frequencies. With the Frequency Domain Solver, I can set it to 'Find port modes only', but that does only a single frequency.
To put it simply: how do I retrieve Zc(omega) [characteristic impedance] and gamma(omega) [propagation constant] of the waveguide port modes only for a wide range of frequencies?
