characteristic curve
Technical term used in engineering, physics, and electronics to describe a graph showing the relationship between two variables that define a system's behavior.
Please measure the characteristic curve of this transistor.
From the characteristic curve, the yield point of this material can be determined.
特性 is a broader term meaning 'characteristic' or 'property', while 特性曲線 specifically refers to the graphical representation of such characteristics.
曲線 simply means 'curve' in a general sense, whereas 特性曲線 is a compound noun with a specific technical meaning.
Compound of 特性 (characteristic) + 曲線 (curve). A straightforward technical term with no irregular etymology.