Ceyear 4041 Series, User Manual

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Chapter XI Performance Characteristics Test
161
11.13 Residual response
Description: The residual response is the discrete response observed on the display when the spectrum analyzer
doesn’t receive input signals.
a) Test device
50

Matched load
b) Test steps
Fig 11-14 Residual Response Testing Setup
Residual response, 10 MHz~20 GHz (preamplifier on)
1) Connect the test device according to Fig 11-14. Connect the 50

matcher with the signal input port of the
spectrum analyzer, and set the spectrum analyzer as follows:
Center frequency .................................................................................................................................. 65 MHz
Frequency step ................................................................................................................................... 100 MHz
Span ................................................................................................................................................... 110 MHz
Reference level ................................................................................................................................... -50 dBm
Preamplifier ................................................................................................................................................. On
Resolution bandwidth ........................................................................................................................... 10 kHz
Video bandwidth ..................................................................................................................................... 3 kHz
2) Activate the limit line function and set the upper limit line at -100 dbm. The noise level shall be at least 5 dB
below the limit line. If not, it is necessary to reduce the noise level by reducing the resolution BW and video
BW.
3) Observe whether there is residual response signal on the noise baseline of the spectrum analyzer. If there is
residual response signal, read the residual response amplitude with the marker and record the measurement
results. During the test, make the residual response signal amplitude 10 dB higher than the displayed average
noise level at least. If the residual response signal amplitude is smaller, further reduce the resolution BW to
reduce the displayed average noise level.
4) Change the center frequency according to [Frequency [Center Freq]
【
↑
】
. Repeat step 3 Check the residual
response of the frequency to 20 GHz, and record the tested maximum response value in the measurement
result of the corresponding test item in the 4041 Series Spectrum Analyzer Record Sheet .
Residual response, 20 GHz~44 GHz (preamplifier on)
50

Matcher
Spectrum
Analyzer