Keysight Technologies N9340B User Manual page 58

Making Measurements
Making Distortion Measurements
Third-Order Intermodulation Distortion
Two-tone, third-order intermodulation (TOI) distortion is
a common test in communication systems. When two
signals are present in a non-linear system, they may
interact and create third-order intermodulation
distortion products that are located close to the original
signals. System components such as amplifiers and
mixers generate these distortion products.
In this example we test a device for third-order
intermodulation using markers. Two sources are used,
one set to 300 MHz and the other to 301 MHz.
1 Connect the equipment as shown in figure below.
This combination of signal generators and directional
coupler (used as a combiner) results in a two-tone
source with very low intermodulation distortion.
Although the distortion from this setup may be better
than the specified performance of the analyzer, it is
useful for determining the TOI performance of the
source/analyzer combination.
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N9310A FUNCTIONS
RF S ignal Generator 9 kHz - 3.0 GHz
Frequency AM I/ Q Utility Preset
Amplitude FM Sw eep File Local
Enter M Pulse Trigger LF Out
7 8 9 MOD
On/ Off
4 5 6
1 2 3
·
0 RF
Remote On/ Off
Standby LF OUT RF OUT 50
On
REVERSE PW R
4W MAX 30 VDC
Signal generator
N9310A FUNCTIONS
RF Signal Generator 9 kHz - 3.0 GHz
Frequency AM I/ Q Utility Prese t
Amplitude FM Sw eep File Local
Ente r M Pulse Trigger LF Out
7 8 9 MOD
On/ Off
4 5 6
1 2 3
·
0 RF
Remote On/ Off
Standby LF OUT RF OUT 50
On
REVERSE PW R
4W MA X 30VDC
Signal generator
Directional
coupler