User`s guide

Agilent E6432A Microwave Synthesizer User’s Guide 3-143
Soft Front Panel Help
I/Q Calibration (Option UNG Only)
• When set to Swapped, the signal that is physically connected to the I
Input on the synthesizer’s hardware front panel is used as the
Q input signal, and the signal that is physically connected to the Q
Input on the synthesizer’s hardware front panel is used as the
I input signal.
• When set to Test Tone, both the I and Q inputs are connected to dc
levels which produce only a carrier feed-through signal with no offset
signals. This is used to verify that the I/Q modulator is functioning
and to provide a known signal level at the output of the I/Q
modulator (0 dBm).
I Attenuation
I Attenuation is used to reduce the level of the signal being applied to
the mixer located within the I/Q modulator circuitry. This attenuator
can reduce the signal level in 2 dB steps and can be adjusted for up to
12 dB of attenuation
Changes made to I Attenuation should also be made to Q Attenuation.
Usually the I and Q signal paths will have the same gain although they
are individually adjustable.
Q Attenuation
Q Attenuation is used to reduce the level of the signal being applied to
the mixer located within the I/Q modulator circuitry. This attenuator
can reduce the signal level in 2 dB steps and can be adjusted for up to
12 dB of attenuation.
Changes made to Q Attenuation should also be made to I Attenuation.
Usually the I and Q signal paths will have the same gain although they
are individually adjustable.
Adjustments to Calibration Settings
The Adjustments to Calibration Settings are only applied to an I/Q
input signal when the Enable check box is selected. When enabled, the
values specified for I Gain, Q Gain, I Offset, Q Offset, and
Quadrature (Offset) are applied as adjustments to the calibration
settings that were selected on the I/Q Calibration dialog box. These are
offsets added to the calibration values.
These gain, offset, and quadrature adjustments are used to compensate
for external I and Q source impairments, while the gain, offset, and
quadrature settings specified by selecting the Calibrate I/Q Modulator
button are used to compensate for I and Q impairments within the I/Q
modulator circuitry