Ceyear 4051 Series, User Manual

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4. Operating Instruction
4.1 Function operation guide
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3) Execute power trigger measurement
The trigger input signal corresponding to the power trigger is the power frequency signal of AC power supply
provided for Series Signal Analyzer. The circuit inside the Series Signal Analyzer will automatically extract
the signal and convert it into trigger input signal. The trigger polarity and parameters of trigger delay can be
set in such steps of pressing the
【 Trig 】 key on the front panel and then entering [
Line
] menu. The trigger
level is inactive during power trigger and the corresponding Power Trigger Menu is not available.
4) Execute burst signal trigger measurement
The trigger input signal corresponding to the burst signal trigger is the IF (intermediate frequency) signal
envelope outputted by the Series Signal Analyzer at the second IF. Some Series Signal Analyzers are also
known as IF power trigger, then the IF bandwidth is also known as trigger bandwidth. When the burst signal
of the 4051 Series Signal/Spectrum Analyzer is triggering, the trigger bandwidth is about 200 MHz. When the
non-zero bandwidth is being measured, the second IF signal approximately represents the signal of start
frequency relating to the measurement of analyzer; when the zero bandwidth is being measured, the second IF
signal approximately represents the signal of center frequency relating to the measurement of analyzer. As the
Series Signal Analyzer has the IF bandwidth of 200 MHz, the noise limits the setting range of the trigger level,
please refer to the Data Manual of 4051 Series Signal/Spectrum Analyzer for details.
The external trigger level can be set in such steps of pressing the 【 Trig 】 key on the front panel, entering
[RF Burst
▶
], pressing soft menu of [Trigger Level] and then using the number keys, Up/Down key or knob.
Prompt
The trigger level of the burst signal of the 4051 Series Signal/Spectrum Analyzer is set without considering
the amplitude correction and reference level offset, so a larger difference may exist between the trigger level
set by you and the signal level displayed by measurement, which can be eliminated by closing amplitude
correction and modifying reference level offset.
Caution
When the start frequency in the state of nonzero bandwidth measurement or the center frequency in the state
of zero bandwidth measurement is close to 0 Hz and less than 120 MHz, the LO feedthrough will cause the
decrease of the trigger function or failure of trigger of the burst signal.
5) Execute timer trigger measurement
The trigger input signal corresponding to the timer trigger is the signal outputted periodically and regularly
inside the Series Signal Analyzer.
In most cases, it is very complicated and difficult to measure the burst RF signal. Although the burst signal
trigger is helpful for executing some routine measurement work of burst RF signal, measurement cannot be
carried out sometimes due to many limiting conditions, e.g., the power of the burst RF signal to be measured
is too small to from effective trigger signal or the power is less than 100 MHz. If you have already known the
generation period of the signal, the measurement can be carried out by using timer. When the generation
period of the burst RF signal is slow and drifting, or there is difference between the internal time base of
Series Signal Analyzer and that of the device being measured, the measurement can also be carried out in such
way as the 4051 Series Signal/Spectrum Analyzer adjusts the timer trigger offset and open the sync function
of the timer trigger.
For the purpose of better understanding and using the timer trigger function, the sequence diagram relating to
the measurement of the timer trigger is shown in Fig. 4.3. The synchronizing signal of timer trigger in the
figure is selected as the signal from the port of trigger input 1 on the front panel. The waveform at the top of
the figure is the signal waveform of the port of trigger input 1 on the front panel, whose rising edge will cause
the timer to execute sync, then the timer will generate the timing pulse based on the time base provided by the
Series Signal Analyzer until the end of sync source holdoff of timer, then the sync will proceed based on the