Ceyear 4051 Series, User Manual

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4. Operating Instruction
4.1 Function operation guide
78
If the RF input is selected as calibration, namely [
Input Port RF CAL
], any one of three calibration signals
including 500 MHz sine signal, comb wave signal and 4.8 GHz sine signal inside the analyzer can be selected
through [Cal Port].
The internal calibration signals of the Series Signal Analyzer are mainly used to calibration of analyzer. When
the calibration operation is running (the calibration can be carried out to the analyzer with soft menu of [Align
▶ ] by pressing 【 System 】 key on the front panel), the analyzer will automatically select those calibration
signals without concern of users.
Setting the RF input to calibration can help you learn to use the analyzer or judge whether fault exists in the
analyzer.
 Settings of coupling method
The coupling method can be switched with [Input Couple AC DC] menu by pressing 【 Input/Output 】 key
on the front panel and then entering [More 1/2
▶
]. AC represents AC coupling, while DC represents DC
coupling. Signal/spectrum analyzer uses DC coupling by default.
When the input coupling is selected as AC coupling, the blocking capacitor will insert into the back end of the
RF input to prevent the DC signal from entering the internal circuit of the Series Signal Analyzer, so as to
effective protect the Series Signal Analyzer from being damaged due to the DC voltage existing in the RF
input port. However, the AC coupling will limit the frequency measurement range of the Series Signal
Analyzer, mainly the measurement of lower frequency signal, e.g., the input signal less than 10 MHz.
For the signal less than 10 MHz, the measurement performance of the 4051 Series Signal/Spectrum Analyzer
is guaranteed under DC coupling.
If the input coupling is selected as DC coupling, it should be noted that the range of the DC voltage existing in
the RF input port must be ensured between 0 V - 200 mv.
Regardless of DC coupling or AC coupling, the power of the signal of the RF input port cannot 30
dBm (1 W).
 Settings of input impedance
The unit correction value can be modified with [Input Impedance 50 Ω 75 Ω] menu by pressing
【
Input/Output
】
key on the front panel and then entering [More 1/2
▶
]. The actual impedance of the
hardware circuit of the Series Signal Analyzer is 50Ω. The input impedance is only used for the purpose of
calculation, only affecting the measurement results. When the scale of Y Axis uses the voltage or current
(dBmv, dBμV, dBμA, V, A) as the unit, the input impedance only affect the measurement results; while it
uses the power (dBm, W) as the unit, the measurement results are not affected.
When users measure the device with impedance of 75 Ω by using the 75 Ω-50 Ω adapter, it is very meaningful
to set the input impedance as 75 Ω.
3) Set reconstructed signal output (optional)
Multiple auxiliary output ports on the rear panel of the Series Signal Analyzer can be set with [Reconstructed
Signal Output
▶ ] menu by pressing 【 Input/Output 】 key on the front panel. The auxiliary output ports can
help you use the Series Signal Analyzer to construct the measurement system or output to other external
devices to test, while the output port is not applicable to all measurement modes and measurement functions.
 Set reconstructed any IF output (option H04A + H04B)
The 4051 Series Signal/Spectrum Analyzer is to realize the any IF output function with two technological
approaches: the first one is to reconstruct the internal fixed IF signal to any IF signal with the digital
processing technology and output through the ports including narrowband I, narrowband Q and broadband I
(differential) on the rear panel with SMA female connector; the second one is to convert the second IF signal
into the any IF signal through the analog mixer and output, and the corresponding output interface on the rear
panel is IF 2.