RF Choke for DC biasing

For DC biasing for power amplifiers or diode switches, Inductors are often used as RF choke.

How do we decide the value of inductor to use for the RF choke?

Choose a value of inductance that gives reactance of about 10 times the impedance at the point you are injecting the bias. This will not disturb teh circuit too much.

As inductance increases, current handling and self resonance frequency decrease. Make sure you are not too close to self resonance at your highest frequency, yet have enough reactance at your lowest frequency.

Hi

My feeling is you should use a coil with a SRF which is at least 2 to 3 times the operating freq. Eventually use a small series resistor still if possible.
Or use one of the more broadband beads of course. Everything wat is resonant in the neighbourhood of your operating freq. can be a problem.

rgds

Normally using large value of RF choke to increase total impedance

Read carefully to the end:

http://www.avx.com/docs/techinfo/avxemisol.pdf

hi
try this tutorial.I think it can help you
http://www.zen118213.zen.co.uk/RFMic...s_Circuits.pdf