design prescaler frequency

[haohaodk46]

Hi all !
I want make a prescaler about 3000 to divider frequency from 2.1Ghz.So how i can make it?
Thanks !

 

[BigBoss]

Do you want to implement it by yourself using with transistors?? Or will you use standard prescaler in the market ??

 

[haohaodk46]

What is the IC can divider frequency up to 3000 factor?

 

[davenn]

maybe you had better explain what you are trying to do
why do you need such a high division amount ?

Dave

 

[haohaodk46]

I want measure frequency VCO up to 2.1Ghz.But high frequency should not be measure direct by microcontroller,So I just need division frequency about 3000.

 

[BigBoss]

I want measure frequency VCO up to 2.1Ghz.But high frequency should not be measure direct by microcontroller,So I just need division frequency about 3000.

Finding a divider circuit standalone is pretty difficult.There is a a bit more complex Integer/Fractional divider circuit by Hittite but I think it's expensive,I'm not sure..
If you intend to measure the "frequency only", why you don't use Mixer+VCO to obtain a lower frequency ?? It's more practical and there are many mixer and VCO circuits in the market.
You will obtain a primitive Spectrum Analyzer..Think about it...

 

[haohaodk46]

Thanks you,but I dont understand why use Mixer + VCO to obtain a lower frequency.Can you explain or any document ?

 

[BigBoss]

Thanks you,but I dont understand why use Mixer + VCO to obtain a lower frequency.Can you explain or any document ?

Simple..
You downconvert your VCO signal around-for instance 5MHz-and the you can measure the frequency of the main VCO.If you change the frequency,this IF will follow the changings.For example..

2.1GHz-->Mixer+Osc-->IF=5MHz so Osc frequency will be 2105MHz fixed.
2GHz -->Mixer+Osc-->IF=105MHz
1.9GHz-->Mixer+Osc-->IF=205MHz...
so on..
This IF frequencies can be measured easily by using ADC or modern ADC equipped Microcontollers..

Or you can use 2ndIF to decrease this frequency more..

 

[haohaodk46]

Thanks.With IF frequecny are 5,105,208 still too big to microcontroller can meaured.Perhap have use 2ndIF.But here matter how to creare a OSC frequency standard and upto 2105Mhz.