Ceyear 4051 Series, Руководство пользователя

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4. Operating Instruction
4.2 Advanced operation guide
116
Fig. 4.31 Measure SNR
4.2.5.3 Measure noise with noise marker function
In this example, the noise marker function will be used to measure the noise of 1 Hz bandwidth with 500 MHz
internal calibration signal.
Step 1. Input 500 MHz internal calibration signal into the analyzer:
 Press
【
Input/Output
】
, [Input Port RF Cal] to select calibration port.
 Press [Cal Port] and [500 MHz] to select 500 MHz Calibration signal.
Step 2. set center frequency, frequency span, reference level and attenuator:
 Press 【 Frequency 】 , [Center Freq] and enter 499.98 MHz.
 Press
【
Span/X Axis
】
, [Span] and enter 100kHz.

Press 【 Amplitude/Y Axis 】 , [RefLevel] and enter -10 dBm.
 Press 【 Amplitude/Y Axis 】 , Press 【 Amplitude/Y Axis 】 , [Attenuation ▶ ], [Mech Atten Auto
Man
] and
enter 40 dB.
Step 3. enable the noise marker:
 Press [Marker Func], [Noise Marker ON OFF]
At such moment the detector mode will be automatically set as power average. If you wish to obtain noise
power under different channel bandwidth, current bandwidth needs to be corrected based on 10×log (BW).
For example, if the noise power within 1 kHz bandwidth is to be obtained, 10×log (1000) or 30 dB has to be
added to the reading.
Step 4. Reduce measurement error by increasing sweep time:
 Press
【
Sweep
】
, [Sweep Time] and enter 3 s.