Why Do Unwrapped Phase Results Look Incorrect

Unwrapped phase results look incorrect.

Phase is unwrapped by post processing simulation data. For unwrapped phase (AngleU option in Measurements dialog) to be correct: the total phase must be less than 180 degrees at the start of the sweep, and there must be enough sweep points so that every 180 degree crossing can be detected. So, best practice is to start at a very low frequency and have enough resolution in the sweep to get at least one phase point per quadrant.