LOW impedance profile contradics filtering in decoupling /noise removal of IC device

Thread Starter

yef smith

Joined Aug 2, 2020
601
Hello,Suppose i have a voltage regulator which is biasing a 10GHZ device as shown bellow.
We have on the ouput of the regulator capacitor network .
1.On one had this network is needs to have low impedaance frofile at 10GHZ so the noise will go to ground instead into the LOAD device.
the profile is described in the photo below.
But as you acn see the capacitor network is in series to the load so i cant see how its going to use the low impedance profile so 10GHZ noise will travel in other direction then load ?
2.the capacitor network is suppose to be a filter which when connected in series filters out noise.
which is perfectly logical.

So how the low impedance profile works together with filtering of the noise?
arethese different designs?
Is low impedance network shown bellow is the same as filter network?
I cant see a contradiction when i look at the network bellow from this different perspectives.
Thanks.

1693166761729.png

1693166060878.png
 

MisterBill2

Joined Jan 23, 2018
16,473
Capacitive devices are only half of filtering, because in every case they are forming a voltage divider with the internal impedance of the voltage source, over some frequency range.
So for more filtering you must also provide a series impedance in the form of an inductance. That may be as simple as a ferrite bead on a conductor that the load current passes through. Or it may include actual inductive components selected to have adequate reactance at the frequency of interest. There is a great deal of literature about filtering, and none of it is on yootoob.
And the inductance must be in series with the load current
 
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