Editing Third-order intercept point (section)

{{Short description|Specific figure of merit in electronics}}
{{Use dmy dates|date=July 2022|cs1-dates=y}}
{{Use list-defined references|date=July 2022}}

In [[telecommunications]], a '''third-order intercept point''' ('''IP<sub>3</sub>''' or '''TOI''') is a specific figure of merit associated with the more general [[third-order intermodulation distortion]] (IMD3), which is a measure for weakly [[nonlinear system]]s and devices, for example [[receiver (radio)|receiver]]s, linear [[electronic amplifier|amplifier]]s and [[frequency mixer|mixer]]s. It is based on the idea that the device nonlinearity can be modeled using a low-order polynomial, derived by means of [[Taylor series]] expansion. The third-order intercept point relates nonlinear products caused by the third-order nonlinear term to the linearly amplified signal, in contrast to the [[second-order intercept point]] that uses second-order terms.

The intercept point is a purely mathematical concept and does not correspond to a practically occurring physical power level. In many cases, it lies far beyond the damage threshold of the device.