I'm looking for software that can simulate an ac circuit. After a quick google, I found several free online services (which I will try out). What I was wondering though is if anyone had some advice concerning my selection. A brief list of requirements: accurate simulation of different conductor behaviours, high frequency simulation (high GHz range but under the THz range), skin effect and proximity effect analysis, ohmic heating, magnetic flux, reflections, magnetic permeability, phase shifting, inductance, eddy current generation, etc. My hopes are to simulate a circuit as close to real world as possible before spending money on actual components. I also realise this may take more than one piece of software or I may have to program some of my own Matlab code. As always, thank you all of you take the time to answer!