PLL-system level measurement

Hi,
Could you suggest me a method for measuring the PLL characteristics(Frequency settling and Amplitude settling due to frequency change). Also which measuring instrument i should use for performing this measurement.

Regards,
Kamesh Kumar S

Agilent has an expensive but complete instrument called Signal Source Analyzer, that can be used to characterize all signal sources, stable as synths or with high jitter such as VCOs.

The best solution, for rich man!

Mazz

For those of us without the latest gear, we can use a diode detector to measure the amplitude of the rf output; and can use a delay line frequency discriminator (signal splitter, delay line, mixer, manual phase shifter) which can tell you both when the frequency is settled, and when the phase is settled, by watching the mixer IF output on an oscilloscope.

Also, if you have access to an old (non-digital) spectrum analyzer, you can tune the PLL frequency from F1 then briefly to F2 then back to F1 for a longer time, and can see the settling time as the "ghost image" on the analog spectrum analyzer face centered at F2. By varying the time the PLL is allowed to dwell on F2, you can plot the frequency settling time. (this works great for VCO's too).

You can also use a gated frequency counter and repeatedly switch from F1 to F2, and eventually building up what frequency near F2 you have settled to in the gate time.

Rich

Thanks Rich.

Could anyone help me with application note/ White paper / IEEE paper relevant to PLL measurements (Frequency/ Amplitude settling).

Regards,
Kamesh Kumar

I may use oscilloscope to capture some IF sine wave and then calculate out the lock time and in-band phase noise. Such a method has a fine resolution.