How to synchronize the RF source having delay over time?

  • #1
K-Manu
6
0
TL;DR Summary
RF source synchronization method
I want to synchronize the RF power supply (having jitter or delay over temp/time) to RF reference frequency with a digital delay generator, and I thought of two ways.

1) phase locked loop: it is commonly used for synchronizing the high-frequency signal, but as I know it is proper for a periodic AC source, and mine is an aperiodic source.

2) Edge-controlled phase detector: Detected phase difference between two sources and applying it to a delay generator would be the idealized method. But I could not find proper user-friendly products (IC is not proper because I'm poor at that).

or there would be a better way to solve it. Please share your experience and correct my knowledge. :)
 
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  • #2
I need some context.
What is "the RF power supply" ?
What is the HF RF source ?
What are you trying to synchronize what with ?
Why are you wanting to do that ?
 
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  • #3
Baluncore said:
I need some context.
What is "the RF power supply" ?
What is the HF RF source ?
What are you trying to synchronize what with ?
Why are you wanting to do that ?

I'm using the RF(13.56 MHz) power generator (power supply) having delay, and I wanna synchronize RF signal what I made using digital delay generator with power generator to make a pulse signal as used to external trigger.
 
  • #4
Is this RF being used for 13.56 MHz ISM (industrial, scientific or medical) dielectric heating?
What is your application?

Newer ISM equipment employs a signal generator, followed by a linear power amplifier.
Older ISM equipment employs a free running, class C oscillator, are you trying to lock that to a precise frequency?
What is the power, make and model of the 13.56 MHz RF power generator?

The answer will become obvious, once we identify the meaning of the question.
 
  • #5
Baluncore said:
Is this RF being used for 13.56 MHz ISM (industrial, scientific or medical) dielectric heating?
What is your application?

Newer ISM equipment employs a signal generator, followed by a linear power amplifier.
Older ISM equipment employs a free running, class C oscillator, are you trying to lock that to a precise frequency?
What is the power, make and model of the 13.56 MHz RF power generator?

The answer will become obvious, once we identify the meaning of the question.
Sorry to what I didn't mention about detaill information, (because I thought it was not essential.)

An RF power generator is used for gas discharge, and I wanna measure its characteristic it (via electrical probe) at the specific moment (<10 ns) in an RF period. Thus I wanna insert the external trigger signal into my electrical probe using a delay generator.

RF input Power: 170, voltage: 300-1000 V, current 0.1-0.5 mA (roughly)
 
  • #6
K-Manu said:
mine is an aperiodic source.
This is where I get confused. Say V = V0 + f(t). As you say, if f(t) is a sine wave, a PLL is a common solution,. But you say f(t) is not periodic - so doesn't that mean synchronization has to predict what f(t) will be?

Or are you really talking demodulation? (And possibly a modulation after that)
 
  • #7
Will you sample with the electrical probe, at every positive zero-crossing of the RF generator, or less often?
How often can the electrical probe take a sample?
 
  • #8
K-Manu said:
TL;DR Summary: RF source synchronization method

phase locked loop: it is commonly used for synchronizing the high-frequency signal, but as I know it is proper for a periodic AC source, and mine is an aperiodic source.
According to my limited understanding, in a generally simple system, only two periodic signals can be synchronized. This method uses the output of the phase comparator for feedback control, ultimately changing the frequency and phase of one periodic signal so that it is the same frequency as the other periodic signal, and the phase difference of the two periodic signals also remains constant. In this case, the phase comparator can be analog or digital.

Synchronization of non-periodic signals is beyond my knowledge. I think this should belong to a higher level of scientific research, and I would like to know more.

If you want to control the timing relationship between a periodic signal and another non-periodic signal (or between two aperiodic signals) in a simple system , I think it can simply be called a signal triggering process, which is different from two periodic signals being completely synchronized.

K-Manu said:
TL;DR Summary: RF source synchronization method

Edge-controlled phase detector: Detected phase difference between two sources and applying it to a delay generator would be the idealized method. But I could not find proper user-friendly products (IC is not proper because I'm poor at that)
I don't know the actual specifications and control methods of your RF power generator. Is there an input to control its frequency or do you just want to use a trigger signal to have it provide power to discharge the gas once

Regardless, if you want PLL control, using an IC seems necessary unless you have the ability to make a PLL control circuit using discrete components. :smile:
 
  • #9
Of course, we can easily generate two synchronized periodic or even aperiodic signals by passing one signal through a delay generator to trigger another signal, but this does not require a phase locked loop.

If we need to change the frequency and phase of an existing periodic signal to synchronize it with another periodic signal, we can use phase locked loop, which requires a process of phase comparison and negative feedback to complete the task.

They are two essentially different processes suitable for different applications.:wideeyed:
 
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1. What causes the delay in RF sources over time?

Delays in RF (Radio Frequency) sources over time can be caused by several factors including temperature fluctuations, aging of electronic components, power supply variations, and environmental changes such as humidity and pressure. Additionally, inherent instabilities in the oscillator components can also lead to frequency drifts and delays.

2. How can one measure the delay in an RF source?

To measure the delay in an RF source, one can use techniques such as time-domain reflectometry or use a frequency counter to observe changes in the frequency over time. More sophisticated methods might include phase noise analysis or using a spectrum analyzer to monitor the stability and consistency of the RF signal.

3. What are common methods to synchronize RF sources with delays?

Common methods to synchronize RF sources with delays include using phase-locked loops (PLLs), which lock the phase of the RF source to a reference signal, thereby stabilizing the frequency. Another method is to use a reference oscillator that is known to be highly stable and synchronize all RF sources to this reference. Additionally, digital signal processing techniques can be used to adjust and compensate for the time delays.

4. Are there any tools or software recommended for synchronizing RF sources?

Yes, there are several tools and software packages available for synchronizing RF sources. Software such as MATLAB or LabVIEW often comes with instrument control toolboxes that can interface with RF equipment and provide algorithms for synchronization. Additionally, specific RF equipment manufacturers might provide their own proprietary software tools designed to work seamlessly with their hardware.

5. What are the potential impacts of not synchronizing RF sources properly?

Not synchronizing RF sources properly can lead to several issues such as signal interference, reduced signal integrity, and inaccuracies in data transmission or measurement. In systems where timing is critical, such as in radar systems or telecommunications, these issues can degrade the overall system performance and might even lead to system failures or data loss.

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