3 VMA Mode
3.1 Digital Demod Measurement
The instrument takes the preamp gain into account as it sweeps. If you sweep
outside of the range of the preamp, the instrument will also account for that. The
displayed result always reflects the correct gain.
For some measurements, when the preamp is on and any part of the displayed
frequency range is below the lowest frequency for which the preamp has
specifications, a warning condition message appears in the status line. For example,
for a preamp with a 9kHz lowest specified frequency: "Preamp: Accy unspec’d
below 9 kHz".
Selection Example Note
Off :POW:GAIN OFF
Low Band :POW:GAIN ON
:POW:GAIN:BAND
LOW
Sets the internal preamp to use only the low band. The
frequency range of the installed (optional) low-band
preamp is displayed in square brackets on the Low Band
selection in the dropdown
Full Range :POW:GAIN ON
:POW:GAIN:BAND
FULL
Sets the internal preamp to use its full range. The low
band (0-3.6GHz, 0-3.4GHz, 0-3GHz, depending on the
model) is supplied by the low band preamp and the
frequencies above low band are supplied by the high
band preamp
The frequency range of the installed (optional) low-band
preamp is displayed in square brackets on the Full Range
selection in the dropdown. If the high band option is not
installed the Full Range selection does not appear
NOTE
The maximum Center Frequency for Low Band, displayed in square brackets,
can change based on the selected IFBW for measurements that support IFBW
(for example, Waveform measurement across all Modes that support it). In
certain models (such as N9042B & N9032B), IFBW values <= 40MHz have a
maximum Low Band frequency of 3.6GHz, while 40MHz < IFBW <= 1GHz
have a maximum of 3.3GHz, and 1GHz < IFBW <= 1.5GHz have a maximum of
3.5GHz. IFBW values > 1.5GHz do not support a Center Frequency that can
reach the Low Band maximum frequency. In these cases, N/A is displayed in the
square brackets for Low Band.
Remote Command
[:SENSe]:POWer[:RF]:GAIN:BAND LOW | FULL
[:SENSe]:POWer[:RF]:GAIN:BAND?
Example
:POW:GAIN:BAND LOW
:POW:GAIN:BAND?
Dependencies Not available on all hardware platforms. If the preamp is not present or is unlicensed, this control is
not shown
Does not appear in VXT Models M9410A/11A/15A/16A nor in M9410E/11E/15E/16E
If :POW:GAIN:BAND FULL is sent when a low band preamp is available, the preamp band
parameter is set to LOW instead of FULL, and an "Option not installed" message is generated
257 Vector Modulation Analyzer Mode User's &Programmer's Reference