Why Do I Sometimes See Negative Mutual Inductance in 2D Extractor - White Paper

Sometimes 2D Extractor returns an inductance (L) matrix whose entries cause concern. Some users are surprised to see a negative off‐diagonal term in the inductance matrix (mutual inductance) because these entries are often all positive. Please be assured that these results are correct and not a cause for worry. This note attempts to explain why this is so.