Agilent Technologies N9010A - Manual (Page 118)

118 Chapter 8
Option EA3 - Electronic Attenuator, 3.6 GHz
Other Electronic Attenuator Specifications
Description Specifications Supplemental Information
Distortions and Noise When using the electronic attenuator, the
mechanical attenuator is also in-circuit. The full
mechanical attenuator range is available
a
.
1 dB Gain Compression Point The 1 dB compression point will be nominally
higher with the electronic attenuator “Enabled”
than with it not Enabled by the loss,
b
except
with high settings of electronic attenuation
c
.
Displayed Average Noise Level Instrument Displayed Average Noise Level will
nominally be worse with the electronic
attenuator “Enabled” than with it not Enabled
by the loss
b
.
Second Harmonic Distortion Instrument Second Harmonic Distortion will
nominally be better in terms of the second
harmonic intercept (SHI) with the electronic
attenuator “Enabled” than with it not Enabled
by the loss
b
.
Third-order Intermodulation
Distortion Instrument TOI will nominally be better with
the electronic attenuator “Enabled” than with it
not Enabled by the loss
b
except for the
combination of high attenuation setting and
high signal frequency
d
.
a. The electronic attenuator is calibrated for its frequency response only with the mechanical attenuator
set to its preferred setting of 10 dB.
b. The loss of the electronic attenuator is nominally given by its attenuation plus its excess loss. That
excess loss is nominally 2 dB from 0
− 500 MHz and increases by nominally another 1 dB/GHz for fre-
quencies above 500 MHz.
c. An additional compression mechanism is present at high electronic attenuator settings. The mechanism
gives nominally 1 dB compression at +20 dBm at the internal electronic attenuator input. The compres-
sion threshold at the RF input is higher than that at the internal electronic attenuator input by the
mechanical attenuation. The mechanism has negligible effect for electronic attenuations of 0 through
14 dB.
d. The TOI performance improvement due to electronic attenuator loss is limited at high frequencies,
such that the TOI reaches a limit of nominally +45 dBm at 3.6 GHz, with the preferred mechanical
attenuator setting of 10 dB, and the maximum electronic attenuation of 24 dB. The TOI will change in
direct proportion to changes in mechanical attenuation.