how to get a temperature insensitive frequency?

[liletian]

crystals temperature frequency

Hi Guys
Can any of you explain how the cell phone industry get a very fixed frequency transmitter? I am doing a system which need to generate a signal at 2.2GHZ without temperature sensitive from 0 C to 40 C? Can anyone explain or give me some sources how to generate a stable frequency transmitter? I heard it seems to come from a extreme stable crystal to use PLL to generate the stable frequency. I hope someone can explain it more to me.
Thanks a lot,
B

 

[Mazz]

tcxo wikipedia

The argument you are looking for is: RF synthesizer.
It can be a very large explanation. How much time will you spend on it?
Mazz

 

[liletian]

Maybe one or two weeks or more, can you give some book or online link on how to implement it?
Thanks

 

[kspalla]

TCXO and OCXO are stable and are defined by PPM. The synthesizer just multiplies this frequency to the desired 2.2GHz.

 

[liletian]

TCXO and OCXO are stable and are defined by PPM. The synthesizer just multiplies this frequency to the desired 2.2GHz.

Can you explain more? what's TCXO and OCXO? what's PPM?
thanks a lot

 

[kspalla]

Crystals are one of the stable signal generators, now atomic clock is the highly stable in recent times.
How ever crystal can be tuned by temperature, voltage etc.

TCXO --> Temperature compensated crystal oscillator
VCXO --> Voltage controlled crystal oscillator
OCXO--->Owen controlled crystal oscillator
PPM--> parts per million
Get the additional details from below links

https://www.wenzel.com/documents/tcxo.html
https://www.vectron.com/products/appnotes/index.htm
**broken link removed**

 

[liletian]

This is great, so for mobile industry, they use TCXO as base band frequency and boost it to GHZ? can you explain how to use synthesis to boost frequency from Mhz to GHz? Any book or online source will be greatly appreciated.
Thanks

Crystals are one of the stable signal generators, now atomic clock is the highly stable in recent times.
How ever crystal can be tuned by temperature, voltage etc.

TCXO --> Temperature compensated crystal oscillator
VCXO --> Voltage controlled crystal oscillator
OCXO--->Owen controlled crystal oscillator
PPM--> parts per million
Get the additional details from below links

https://www.wenzel.com/documents/tcxo.html
https://www.vectron.com/products/appnotes/index.htm
**broken link removed**

 

[Element_115]

Use a PLL with the VCXO(or TCXO) as the REF Oscillator.
https://en.wikipedia.org/wiki/Phase-locked_loop

"REF Oscillator" = Master Oscillator

 

[liletian]

I think my question is not very clear, my question is actually how to boost frequency by PLL? For example, one crystal have frequency of 100MHZ, how to generate an exactly 2GHZ frequency?
Thanks

Use a PLL with the VCXO(or TCXO) as the REF Oscillator.
https://en.wikipedia.org/wiki/Phase-locked_loop

"REF Oscillator" = Master Oscillator

 

[Mazz]

For a couple of week'job let me suggest a good starting book (free) is at **broken link removed**
Mazz