User`s guide

3-30 Agilent E6432A Microwave Synthesizer User’s Guide

Soft Front Panel Help

ALC System Diagram

Coupled Operation

During coupled operation, the ALC and attenuation values are changed

together.

Since many applications require output power less than –20 dBm, an

optional step attenuator (Option 1E1) can be used. Lower output power

can be achieved when the step attenuator and level control circuits

work in conjunction. With the step attenuator, the ALC level is

normally used over the smaller, more accurate portion of its range.

Since ALC level accuracy suffers below –10 dBm, the ALC level is set

between –10 and 0 dBm with the following exceptions:

• When the step attenuator is set to 70 dB, the ALC is allowed to go

down to –20 dBm.

• When the step attenuator is set to 0 dB, the ALC is allowed to go to

maximum power; maximum power varies depending on whether

your synthesizer is a standard model or a high power option.

When you set output power, coupled operation is assumed by the

VXIplug&play driver unless leveling is set to off. The proper

combination of ALC level and step attenuator setting is decided by the

VXIplug&play driver. In coupled operation, when desired output power

is set, by adjusting the Output Power value from the main Soft Front

Panel, the ALC level and step attenuator are set automatically to

provide the best accuracy for the output power requested.