Ceyear 4051 Series, User Manual

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4. Operating Instruction
4.1 Function operation guide
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signal spectrum exchange with each other centering around center frequency, then the inversion can be
switched with the [Spectrum Inversion Switch] soft menu.
The IF output frequency can also be adjusted with the menu of [Reconstructed IF ▶ ] and [Digital Gains]. The
gain of the 4051 Series Signal/Spectrum Analyzer is 0 dB by default, then the IF output power is 8 dB - 12 dB
less than the RF output power, e.g., if the RF intput power is -10 dBm, the IF output power is -18 dBm to -22
dBm. If you set the digital gain as 6 dB, the IF output power will amplify by 6 dB.
Caution
To change the output SNR
The adjustment function of digital gain in the [Reconstructed IF
▶
] menu is realized through the digital
processing technology, so the parameters are only used to adjust the IF output power instead of changing the
output SNR.
If you hope to change the output SNR, the parameters including reference level, attenuator, PreAmplifier, etc.
Can be set with [Amplitude/Axis] key.
 Set AM/FM demodulation output (option H04A + H04B)
The 4051 Series Signal/Spectrum Analyzer demodulates the AM/FM signal with digital technology and
outputs through the ports including narrowband I, narrowband Q, broadband I (differential) and broadband Q
(differential) on the rear panel with SMA female connector. The step configuration is carried out for the
demodulation bandwidth within 100 Hz - 200 MHz on the basis of 1-2-5. Only when the 40 MHz broadband
digital IF (option H38A) or 200 MHz broadband digital IF (option H38B) is configured is the function of
AM/FM demodulation output enabled, while the AM/FM demodulation output (option H04A) is being
configured. The demodulation bandwidth range varies with different options selected, the specific mapping
relation is shown in Table 4.3.
Table 4.3 AM/FM Demodulation Output Function and Option Configuration Relation Table
Configuration
Combination of Options Demodulation Bandwidth
(Narrowband I and Narrowband Q
Port)
Demodulation Bandwidth
(Broadband I and Broadband Q Port)
Option H04A Demodulation bandwidth: ≤ 10 MHz Invalid
Option H04A +
Option H38A Demodulation bandwidth: ≤ 40 MHz Invalid
Option H04A + H04B +
Option H38A + H38B Demodulation bandwidth: ≤ 40 MHz Demodulation bandwidth:
50 MHz/100 MHz/200 MHz
When the reconstructed signal output is selected as the AM/FM demodulation output, the narrowband I or
broadband I port outputs AM demodulation signal, while narrowband Q or broadband Q port outputs FM
demodulation signal.
The [AM Digital Gain] and the [FM Digital Gain] in the [AM/FM Demodulation ▶ ] menu is available for the
adjustment of output voltage. The gain of the 4051 Series Signal/Spectrum Analyzer is 0 dB by default, so the
output voltage of the demodulation signal will double if you set the output gain as 6 dB.
 Set detector output
The 4051 Series Signal/Spectrum Analyzer carries out the envelope detector and logarithmic detector for the
RF signal with digital processing technology and outputs through the narrowband I port on the rear panel with
SMA female connector. The step configuration is carried out for the detector bandwidth within 100 Hz - 10
MHz on the basis of 1-2-5. When the 40 MHz broadband digital IF (option H38A) is being configured, the
detector bandwidth can be extended to 40 MHz.
You can set the output as logarithm or linearity with the [Output Options] in the [Detector Output ▶ ] menu,
while the default setting of the 4051 Series Signal/Spectrum Analyzer is logarithm. The [FM Digital Gain] in