Agilent Technologies X Series Manual page 395

Input Z Correction
Sets the input impedance for unit conversions. This affects the results when the y-axis unit is voltage or
current units (dBmV, dBµV, dBµA, V, A), but not when it is power units (dBm, W). The impedance you
select is for computational purposes only, since the actual impedance is set by internal hardware to 50
ohms. Setting the computational input impedance to 75 ohms is useful when using a 75 ohm to 50 ohm
adapter to measure a 75 ohm device on an analyzer with a 50 ohm input impedance.
There are a variety ways to make 50 to 75 ohm transitions, such as impedance transformers or minimum
loss pads. The choice of the solution that is best for your measurement situation requires balancing the
amount of loss that you can tolerate with the amount of measurement frequency range that you need. If
you are using one of these pads/adaptors with the
key. This function is used to set a correction value to compensate for the gain (loss) through
Ext Gain
your pad. This correction factor is applied to the displayed measurement values.
Key Path
Remote Command
Example
Preset
State Saved
Readback
Initial S/W Revision
RF Coupling
Specifies alternating current (AC) or direct current (DC) coupling at the analyzer RF input port.
Selecting AC coupling switches in a blocking capacitor that blocks any DC voltage present at the
analyzer input. This decreases the input frequency range of the analyzer, but prevents damage to the
input circuitry of the analyzer if there is a DC voltage present at the RF input.
In AC coupling mode, you can view signals below the corner frequency of the DC block, but below a
certain frequency the amplitude accuracy is not specified. The frequency below which specifications do
not apply is:
X-Series Model
N9000A
Input/Output, RF Input
[:SENSe]:CORRection:IMPedance[:INPut][:MAGNitude] 50|75
[:SENSe]:CORRection:IMPedance[:INPut][:MAGNitude]?
CORR:IMP 75 sets the input impedance correction to 75 ohms.
CORR:IMP?
This is unaffected by a Preset but is set to 50 ohms on a "Restore Input/Output
Defaults" or "Restore System Defaults->All"
Some instruments/options may have 75 ohms available.
Saved in instrument state
50 Ω or 75 Ω. Current setting reads back to the RF key.
Prior to A.02.00
Lowest Freq for meeting specs when AC coupled
9 kHz
Input Z Corr function, you might also want to use the
Input/Output
Lowest Freq for meeting
specs when DC coupled
n/a
395