Why are you using more than one solver? Isn't that a lot of overhead?

No, quite the opposite. Instead of overextending CPU and computer memory usage by forcing one solver to mesh and converge for the most inconvenient geometry in your circuit, μWave Wizard divides a complex circuit up into smaller subcircuits and solves each one of them with a solver best suited for that particular circuit. Then all individual solutions are combined to obtain the RF performance of the entire structure.