3 Spectrum Analyzer Mode
3.10 TOI Measurement
Backwards Compatibility Command Current Command
:MEASure:TOINtercept[n]? :MEASure:TOI[n]?
:READ:TOINtercept[n]? :READ:TOI[n]?
:FETCh:TOINtercept[n]:IP3? :FETCh:TOI:IP3?
:MEASure:TOINtercept[n]:IP3? :MEASure:TOI:IP3?
:READ:TOINtercept[n]:IP3? :READ:TOI:IP3?
Measurement Details
The TOI measurement begins by taking a sweep using the current center frequency
and span. It chooses the two highest peaks as the lower and upper tone
frequencies, F
Lower
and F
Upper
. Then the third-order intermod frequencies are
computed as:
ILower
= 2F
Lower
- F
Upper
I
Upper
= 2F
Upper
- F
Lower
The power is then measured at the four frequencies (unless either intermod
frequency falls outside the span).
The third order intercept level is defined (all values expressed in dBm) as:
The third order delta level is defined (all values expressed in dBm) as:
Both values are computed, and the TOI is reported as the worst of the two
measurements.
There are two approaches to TOI measurement acquisition. The first approach is a
simple method to use a single sweep. This method gives the quickest approximate
Spectrum Analyzer Mode User's &Programmer's Reference 1757