Emerson R&S SGT100A User Manual page 239

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R&S SGT100A
About power servoing
Component tests are complicated by the fact that they can be defined as a function of
the DUT output power, e.g. a power amplifier. To the test engineer, this dependency
poses a problem because the DUT gain is not necessarily:
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Known beforehand
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Constant over the input power
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Constant over time or temperature
By using the R&S SGT / R&S NRQ6 power servoing and the high-speed remote con-
trol of the R&S SGT, setting the desired power typically takes 1 ms to 1.5 ms. The
function is much faster than using a traditional SCPI based control loop.
To achieve short setting periods:
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The power sensor measures continuously and sends results using a dedicated
serial connection to the signal generator - direct field-programmable gate array
(FPGA) to FPGA communication, no SCPI overhead.
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The control algorithm runs on the signal generator - again, no SCPI overhead. The
application only needs to set the desired level in one command.
Test setup
Required equipment:
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R&S SGT
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R&S NRQ6 power sensor with power servoing option R&S NRQ6-K2
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Computer equipped with the R&S SGMA-GUI software for control of the R&S SGT
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DUT
User Manual 1176.8674.02 ─ 12
Signal generator settings
RF settings
239