Agilent Technologies HP 83711A, User Manual

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Ke ys/Shifted Functions
EXT DIODE
Figure 6-1. External Diode Detector Leveling Setup
When external diode detector leveling is chosen, power is sampled at the
external sampling device (either a directional coupler or power splitter) by an
external diode detector that is typically operating in the square law region.
When the diode detector is operating in the square law region, it will provide
a DC voltage that is proportional to the power sampled at the input to the
detector . This DC voltage is fed back to the synthesizer via the ALC IN
connector . The synthesizer then adjusts its output power level to maintain a
constant power level at the input to the external diode detector .
Applications
External leveling can be used when your application requires long cables
that will cause frequency-dependent losses . It also enables devices , such as
ampliers , mixers , etc. to be inserted into the RF signal path so that the
output of the inserted device is controlled by the synthesizer .
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