The What, How, and When of an RF choke?

Often used for decoupling various stages in an RF system. the L of choke forms a high resistance and prevents disturbances in one section from going to another. the bypass capacitor shunts these disturbances to ground. So one can use say 4 stages all operating from same supply but isolated by RF chokes.

It is basically a coil of inductance having adequate at the frequency at which it has to perform decoupling.

It works as any other inductor will work. Its impednace is proportinal to frequency.

If you know the frequencies that should not be allowed to disturb other sections, then choose L to give an impedance of say 100 ohms at that frequency and choose capacitor with impednace of less than 1 ohm at this frequency. Supply is fed through this choke to this section, and capacitor is right across this section.

What Is An Rf Choke

"RF" of course means "Radio (high) Frequency" and "choke" refers to choking it off or blocking it. It would be used in series with a circuit that will be adversely affected in some way by the presence of RF, but must operate in the presence of it. It will be a coil or possibly a more sophisticated circuit, which does not present a significant impedance up to frequencies the protected circuit is intended to process

Read more: What is an RF Choke and why would I use one? | Answerbag http://www.answerbag.com/q_view/46951#ixzz1MD6OLKZ...