External Leveling Used With The Optional Step Attenuator - HP 8360 B Series User Manual

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External Leveling Used With the Optional Step Attenuator

Some external leveling applications require low output power from
the swept signal generator. The swept signal generator automatically
uncouples the attenuator from the ALC system for all external
leveling points.
( ).
Press Note the display. It shows:
POWER LEVEL
For example, leveling the output of a 30 dB gain amplifier to a
level of -10 dBm requires the output of the swept signal generator
to be around -40 dBm when leveled. At some frequencies this
level is beyond the range of the ALC modulator alone. If so, the
LOW UNLVLED warning message is
attenuation results in an ALC level of 0 dBm, which is well within
the range of the ALC. At 20 GHz, 30 dB attenuation is a better
choice as it results in an ALC level of -10 dBm. This gives a margin
for AM or other functions that vary the power level.
For optimum display accuracy and minimum noise, the ALC
level should be greater than -10 dBm. This is achieved by using
attenuation equal to the tens digit of output power. Example:
desired output power = -43 dBm; use:
40 dB, ALC -3 dBm
1. Press POWER (j).
To obtain flatness corrected power, refer to "Creating and Applying
the User Flatness Correction Array" in the "Optimizing Swept Signal
Generator Performance" section.
displayed. Inserting 40 dB of