I have a situation where I am getting a non-real solution to my momentum problem. I started out with a capacitor coupled psuedo lumped element resonator tied to a CPW line. I got some funky results, so I effectively removed the coupling capacitor to the resonant circuit and tried again. I get GAIN at approximately the resonant frequency of the circuit (which shouldn't be physcially possible). I've tried different mesh densities etc to no avail. Is anyone at Keysight interested in trying out my circuit to see why the simulation is failing? It's quite possible it's something I've done, but shouldn't the simulator check for non-physicality?