U2021XA Datasheet, PDF (7/20 Pages) Keysight Technologies – U2020 X-Series USB Peak and Average Power Sensors

07 | Keysight | U2020 X-Series USB Peak and Average Power Sensors – Data Sheet
Measured Rise Time Percentage Error Versus Signal-Under-Test Rise Time
Figure 1. Measured rise time percentage error versus signal under test rise time
Although the rise time specification is
≤ 13 ns, this does not mean that the
U2021XA/22XA can accurately measure
a signal with a known rise time of 13 ns.
The measured rise time is the root sum of
the squares (RSS) of the signal-under-test
(SUT) rise time and the system rise time
(13 ns):
Measured rise time = √((SUT rise time)² + (system rise time)²) and the % error is:
% Error = ((measured rise time – SUT rise time)/SUT rise time) × 100
Power Linearity
Power range
–20 dBm to –10 dBm
–10 dBm to 15 dBm
15 dBm to 20 dBm
Linearity at 5 dB step (%)
25 °C
0 to 55 °C
1.2
1.8
1.2
1.2
1.4
2.1
Video Bandwidth
The video bandwidth in the U2021XA/
22XA can be set to High, Medium, Low,
and Off. The video bandwidths stated
below are not the 3 dB bandwidths, as
the video bandwidths are corrected for
optimal flatness (except the Off filter).
Refer to Figure 2, “Characteristic peak
flatness,” for information on the flatness
response. The Off video bandwidth setting
provides the warranted rise time and fall
time specifications and is the recom-
mended setting for minimizing overshoot
on pulse signals.
Video bandwidth setting
Rise time/fall time ¹
Overshoot ²
< 500 MHz
≥ 500 MHz
Low: 5 MHz
< 93 ns
< 82 ns
Medium: 15 MHz
< 75 ns
< 27 ns
High: 30 MHz
< 72 ns
< 17 ns
Off
< 73 ns
< 13 ns ³
< 5%
1.  Specified as 10% to 90% for rise time and 90% to 10% for fall time on a 0 dBm pulse.
2.  Specified as the overshoot relative to the settled pulse top power. Applicable to signal with rise time ≥ 15 ns
3.  Add 5 ns to rise/fall time specifications for acquisitions smaller than 137.5 µs.