differential inputs vco buffer design

[orikfa]

Where can I find a good tutorial or application note on RF differential inputs vco buffer design?
Thanks.

 

[nbucska]

What do you need? <nbucska@pcperipherals.com>

 

[Lewish]

Why does it matter whether the input to the VCO is differential or single-ended?

 

[orikfa]

Due the impossibility to realize an integrated one, I have abbandoned the idea. I will design a Colpitts VCO using discrete components(JFET or BJT), where can I find a good design guide?
Bye

 

[Lewish]

If you can't realize one using an integrated circuit, you sure aren't to do a Colpitts VCO.

You had better go take some engineering classes.

 

[nbucska]

What is the problem you are trying to solve ? <nbucska@pcperipherals.com>

 

[orikfa]

With &quot;Due the impossibility to realize an integrated one&quot; I means that I don't have enough time to wait the end of a foundry process for device testing.

 

[orikfa]

With &quot;Due the impossibility to realize an integrated one&quot; I means that I don't have enough time to wait the end of a foundry process for device testing.

 

[Heydave]

There are a number of instrumentation amps that can convert differential to single ended near your VCO. I assume you are wanting differential to avoid noise. The ground reference of the instrumentation amp can be physically layed out to be the exact same point as the VCO ground reference and then ground noise from the source to your VCO is almost eliminated. I think there are some application notes from Analog Devices for a high speed analog multiplier chip that has differential inputs. This one chip might serve as your differential input and VCO. I think you may be limited to a few hundred MHz with this chip.

 

[orikfa]

I have already seen ANALOG DEVICES's application notes and the differential inputs vco buffers produced works below 500Mhz. I need one above 1Ghz.

 

[bowb2k]

Hello,

I am new to the forum. If I read the thread correctly single ended is OK for you but not differential. I have been through this before and recommend converting SE to DE or visa versa using a balun built out of discretes. This technique works very well at 1 GHz.

 

[orikfa]

Thanks, bowb2k.