AC coupling

[miguelgarcia]

Hello

Can some one give any ideas of how to do AC coupling at High speed RF inputs, so I can eliminate DC components
from AC signals?

Lots of thanks in advance,

Miguel Garcia

[greggdaug]

See DC blocks available from MiniCircuits:

http://www.minicircuits.com/products/dc_blocks.shtml

-Gregg

[Bulova]

Hm ... DC-Blocks? Why not just using a simple capacitor in series to the input(s)?

Regards

Dieter

[miguelgarcia]

Hi

" Why not just using a simple capacitor in series to the input(s)? "

Probably because greggdaug thinks we like to spend unnecessary money ?
And, man... They are expensive, in my opinion !!!

Obviously, if we build our own AC coupling network we will have to do
some advanced calculation (not only the cut off point) so it works well,
but this is nothing that can't be achieved.

Miguel

[Bulova]

Hello Miguel,

yes you are right with the costs. In addition to the simple cap one can think about a transient blocker, which is also good for the moment of connecting to a signal source with very high DC value, which could cause a high pulse current and damage the input circuitry. But: Transient blockers are not easy to design, if the shall have no influence to higher frequencies. Something like a smaller resistor in series and an ESD diode to GND.

Regards and nice weekend from Germany to Portugal

Dieter