(TOI)
Use the TO1
The spectrum analyzer computes and displays the third order intercept (TOI) of the displayed signals, marking all four signals with arrows to confirm the correct signal selection. The measurement updates at the end of every sweep, which enables
The third order
TOI = 2 X Amp&ml A - AmP~disto~tion p r o d u c t A + Amplsignal B
2
where the frequency of distortion product A is:
FFldi~to&on product A = 2 2 Freqsignal A - Freqsignal B
Third Order Intercept:
Third order intercept is defined as the absolute power level at which the
The measurement algorithm used by TO1 ON OFF (see above equation) corrects for the two test signals being different amplitudes. The result is a calculated value for the two test signals being equal amplitude, and is independent of the absolute level of either test signal. In order to minimize the measurement error, it is best to keep the test signals as close as possible to the same level and to the top of the screen.
The TO1 measurement accuracy (assuming the measured signals are near the top of the display) is typically about * 1.8 dB.