Ceyear 4051 Series, User Manual

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4. Operating Instruction
4.2 Advanced operation guide
138
Video bandwidth Video
Bandwidth
>
Resolution
Bandwidth
The video bandwidth value should be large enough to make
sure the video bandwidth filter does not weaken the signal
during the rising time.
The parameters are listed in Table 4.5 for the signal trigger events and the simultaneous arrival of pulses,
namely the SD is 0. If the signal is a non-zero delay, it will be added to the recommended value of gate delay.
Table 4.5 Recommended value for measured parameters of the Gate
Pulse width Gate delay Minimum Resolution
Bandwidth
Gate width
20μs
8μs
1MHz
8μs
50μs 40μs
100kHz
8μs
100μs 40μs
100kHz
48μs
500μs 400μs
10kHz
80μs
1ms
600μs
10kHz
200μs
5ms 4ms 1kHz 0.8ms
10ms 6ms 1kHz 2.4ms
50ms 30ms 1kHz 12ms
100ms 50ms 1kHz 24ms
4.2.9.4 Measuring example: to measure the RF pulse signal of FM modulation by the use of gating LO
The example of time gate measurement is a simple pulse signal of frequency modulation, aiming to eliminate
the pulse spectrum to observe the spectrum of FM carrier, which seems to be a continuous signal instead of a
pulse signal. It is possible to reveal the simple modulation behind the pulse spectrum.
Step 1. Generate the FM signal modulated by RF pulse via the signal generator:
There are many ways to generate FM signal modulated by RF pulse. The internal modulation of 1464 series
signal generator is applied to this example, with the parameter shown in Table 4.6.
Table 4.6 Parameters of 1464 series signal generator
Frequency 400 MHz
Amplitude -10dBm
Modulation Pulse modulation On and FM modulation On
Pulse period 5ms (or pulse repetition frequency 200Hz)
Pulse width 4ms
Pulse input Internal auto
FM modulation rate 50kHz
FM frequency offset 1kHz
FMinput For internal
Waveform Sine wave
Step 2. Connect the signal generator and Series Signal Analyzer:
As shown in Fig. 4.56, connect the Series Signal Analyzer and signal generator, where the RF output of signal
generator is connected to the RF input of the analyzer, and the monitoring output port of the signal generator
to the input port of external trigger on the front panel of 4051 Series Signal Analyzer.