What type of inductor to choose fro low pass LC filter 40MHz

[puviarasu]

Selection of inductor

Hi all I want to design a low pass LC filter with cutoff frequency at 40 MHz , can any body give suggestion :idea: in designing the same and confused about what type of inductor to use :?: (ferrite core, non magnetic core or air core) and about the tolerance also.
:!:

 

[Borber]

Re: Selection of inductor

You can use all types. Usually ferrite core is used but you can use allso brass or aluminium core (they are magnetics cores but have negative µr). Air cores are dificult to adjust (stretching).
Inductors are best to be adjustable. Exact inductors for filter design you will not find.

 

[mircea]

Selection of inductor

I suggest a ferrite core or air core. Air is better.

 

[puviarasu]

Re: Selection of inductor

Is there is any relation for the resonating frequency, which is mostly given in the data sheet of most of the inductors while selecting ie my frequency range of interest is 0-10 MHz and if the resonating frequency is 100 MHz?

 

[caesarye]

Re: Selection of inductor

I think you'd better use air.For you can adjust the inductance quantity in the filter real-time.It's very helpful when you are tuning it.And you can get a inducot more easily and quickly.The frequency is not a problem.In the high-frequency filter(usually several hundreds of MHz),I also use the air coils.
If any questions,contact me with e-mail: caesar_ye@sohu.com