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Getting Started
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Keysight U2040 X-Series User’s Guide
aperture to match a particular epoch of the RF signal, for example setting the aperture
equal to a multiple of modulation frequencies in an AM signal, there is the ability to
precisely trigger the occurrence of each measurement. This allows synchronization
between the device under test and the measurement system.
Sometimes it is necessary to examine the time varying characteristics of the power
envelope. This allows measurements of pulse duration time or pulse period for example.
The U2040 X-Series can change when Normal mode is selected to provide 20 MHz
sampling of the power envelope. Similar to the Average mode, the best diode from the 4
ranges is selected transparently within the digital processing. In contrast to Average mode,
no chopper switching is performed and the signal path is a direct coupled differential
amplifier. The analog signal conditioning allows the load resistor and the low pass filter
characteristics to be adjusted. Changing the load resistor also changes the responsiveness
(V/W) of the diode detector and the video bandwidth. Changing the load capacitance will
affect the bandwidth but not the responsiveness. Used together, these controls reduce the
noise of the measurements for low level signals at the expense of video bandwidth.
A high speed trigger input and trigger output are also present in each U2040 X-Series
sensor to allow proper synchronization between test instruments. Besides that, the
Average and Normal mode do support internal level trigger mode on top of external trigger
mode. This allows flexibility in triggering for different input signals over a wide dynamic
range.
A high speed acquisition and processing engine is also present in the U2040 X-Series
sensor to enable a complex calibration scheme to track the performance of various modes
across frequency, input power and temperature. The robust back end system also allows
the U2040 X-Series sensor to be paired with either conventional USB or LAN based
interface. On top of that, the U2040 X-Series sensor is also designed to be thermal vacuum
compliant (TVAC) by controlling the outgas property of the components being used.