Keysight x-series Instruction Manual

3 Short-Range Comms & IoT Mode
3.3 LoRa (CSS) Demodulation Measurement
Auto/Man is remembered and restored when the electronic attenuator is once again disabled. This is
described in more detail in "Elec Atten" on page 1641
See "Attenuator Configurations and Auto/Man" on page 334 for more information on the Auto/Man
functionality
Couplings If the RF Input Port is the RF Input:
–
If the USB Preamp is connected to USB, use 0dB for Mech Atten
–
Otherwise compute the auto-selected value of Mech Atten based on Reference Level, Int Preamp,
External Gain, Ref Level Offset, Max Mixer Level, µW Path Control and IF Gain settings. Limit this
value to be no less than 6dB (total attenuation below 6dB can never be chosen by Auto)
–
In N9041B, if the RF Input Port is RF Input2, use the formula above and subtract the value of "Full
Range Atten" on page 1638 from the result to determine the Mech Atten. Limit the value so that it
is never lower than 0dB and so that total attenuation, including Full Range Atten, is never less
than 6dB (total attenuation, including Full Range Atten below 6dB, can never be chosen by Auto)
In External Mixing and BBIQ, where the attenuator is not in the signal path, the attenuator setting
changes as described above when Mech Atten is in Auto, but no changes are made to the actual
attenuator hardware setting until the input is changed back to the RF Input
For CXA-m with Option FSA (Fine-Step Attenuator or 2dB steps), the FSA-like behavior is only
available when the frequency setting is <=7.5GHz. So, when the frequency is changed from below
7.5GHz to above 7.5GHz, the attenuation setting changes to a multiple of 10dB that is no smaller
than the previous setting. For example, 4dB attenuation changes to 10dB
Preset Auto
The Auto value is 10dB
State Saved Saved in instrument state
Min 0dB
The attenuation set by this control cannot be decreased below 6dB with the knob or step keys. Values
below 6dB must be directly entered from the keypad or via SCPI. This protects against setting a
dangerously small attenuation value, which can put the instrument at risk of damage to input circuitry.
If the current mechanical attenuation is below 6dB, it can be increased with the knob and step keys,
but not decreased
Max
CXA Option 503 or 507 50dB
EXA 60dB
All other models 70dB
Note that in the Single-Attenuator configuration, the total of ATT and EATT cannot exceed 50dB. So, if
the EATT is set to 24dB first, the main attenuation cannot be greater than 26dB and will be reduced
accordingly; if the main attenuator is set to 40dB first, EATT cannot be greater than 10dB
Annotation The current value for Total Atten is displayed in the Measurement Bar at the top of the display. A value
appears for Electronic Attenuation only if the Electronic Attenuator is enabled. The annotation appears
as:
Atten: <total>dB (e<elec>)
The e letter is in amber in Single-Attenuator configurations
Short Range Comms & IoT Mode User's &Programmer's Reference 333

Keysight x-series Specifications

General

Analysis Bandwidth	Up to 1 GHz (depending on model)
Real-Time Bandwidth	Up to 1 GHz (depending on model)
Form Factor	Benchtop
Connectivity	LAN, USB, GPIB
Resolution Bandwidth	1 Hz to 10 MHz (depending on model)