how to get the measure waveform from AFC transient response?

[hhq414]

Hi,all
Recently, I read a paper "A 975-to-1960MHz Fast-Locking Fractional-N Synthesizer with Adaptive Bandwidth Control and 44.5 Prescaler for Digital TV Tuners .pdf" I don't know how to measure and get the picture below, does anyone know?

 

[FvM]

If you expect, that the VCO control voltage represents the present oscillator frequency, it's simply it's waveform.
There are however signal analyzers, that can measure frequency versus time directly.

 

[hhq414]

Re: how to get the measure waveform from AFC transient respo

If you expect, that the VCO control voltage represents the present oscillator frequency, it's simply it's waveform.
There are however signal analyzers, that can measure frequency versus time directly.

THank you, FvM. Have you used the signal analyzers? What's its name?