Agilent Technologies Signal Analyzer N9030a - Manual (Page 591)

6 RLC Swept SA Measurement Front-Panel & SCPI Reference
Input/Output
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 Lowest Freq for
meeting specs when
AC coupled Lowest Freq for
meeting specs when
DC coupled
N9000A–503/507 100 kHz n/a
N9000A-C75 Input 2 1 MHz n/a
N9000A–513/526 10 MHz 9 kHz
N9010A 10 MHz 9 kHz
N9020A 10 MHz 20 Hz
N9030A 10 MHz 3 Hz
Some amplitude specifications apply only when coupling is set to DC. Refer to the appropriate
amplitude specifications and characteristics for your analyzer.
When operating in DC coupled mode, ensure protection of the analyzer input circuitry by limiting
the DC part of the input level to within 200 mV of 0 Vdc. In AC or DC coupling, limit the input RF
power to +30 dBm (1 Watt).
Key Path Input/Output, RF Input
Remote Command :INPut:COUPling AC|DC
:INPut:COUPling?
Example INP:COUP DC
Dependencies This key does not appear in models that are always AC coupled. When the SCPI command to set
DC coupling is sent to these models, it results in the error “Illegal parameter value; This model is
always AC coupled” In these models, the SCPI query INP:COUP? always returns AC.
This key does not appear in models that are always DC coupled.When the SCPI command to set
AC coupling is sent to these models, it results in the error “Illegal parameter value; This
instrument is always DC coupled” In these models, the SCPI query INP:COUP? always returns
DC.
Preset AC on models that support AC coupling
Remote Language Compatibility Measurement Application Reference 591