Agilent Technologies X Series Manual page 358

AMPTD Y Scale
Another disadvantage of the electronic attenuator is that the spectrum analyzer loses its "Auto" setting,
making operation less convenient.
Also, the relationship between the dynamic range specifications (TOI, SHI, compression and noise) and
instrument performance are less well-known with the electrical attenuator. With the mechanical
attenuator, TOI, SHI and compression threshold levels increase dB-for-dB with increasing attenuation,
and the noise floor does as well. With the electronic attenuator, there is an excess attenuation of about 1
to 3 dB between 0 and 3.6 GHz, making the effective TOI, SHI, and so forth, less well known. Excess
attenuation is the actual attenuation relative to stated attenuation. Excess attenuation is accounted for in
the analyzer calibration
Elec Atten
Controls the Electronic Attenuator in dual attenuator configurations. This key does not appear in single
attenuator configurations, as the control of both the mechanical and electronic stages of the single
attenuator is integrated into the single
Key Path
Remote Command
Notes
Dependencies
Preset
State Saved
Min
Max
Initial S/W Revision
Modified at S/W Revision
358
Atten key.
AMPTD Y Scale, Attenuation
[:SENSe]:POWer[:RF]:EATTenuation <rel_ampl>
[:SENSe]:POWer[:RF]:EATTenuation?
Electronic Attenuation's spec is defined only when Mechanical Attenuation is
6 dB.
This key only appears in the dual attenuator configuration. However, in the
single attenuator configuration, EATT SCPI commands are accepted for
compatibility with other X-series instruments and set a "soft" attenuation as
described in "Attenuator Configurations and Auto/Man" on
page 355. The "soft" attenuation is treated as an addition to the "main"
attenuation value set by the Atten softkey or the POW:ATT SCPI command
and affects the total attenuation displayed on the Attenuation key and the
Meas Bar.
When
Enable Elec Atten
0 dB
Saved in instrument state
0 dB
Dual attenuator configuration: 24 dB
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
Prior to A.02.00
A.03.00
is off, the key is grayed out.
Elec Atten