[Moved]: design of unform LC low pass filter

[So.nia]

hello all;
Please , I want to desgin low pass LC filtre with source current in input Rs = infinite


if Rs = infinite how i can normalise the elements of the filter ?

 

[BradtheRad]

An inductor is defined as a component which resists a change in current level. It is driven by current in one way or another. When you have very high resistance, that implies very low Amperes. Then you require an L value which is too large to be practical. In addition the C value becomes extremely small.

Your spec is for a filter which is voltage-driven only. I don't know if there is such a thing.

 

[v_c]

I think you have to define the transfer function of the filter. The transfer function is the ratio of response divided by excitation. If you are going to use a current source input excitation, what is the response you desire? Is the response (output) the voltage at the output of the filter structure? Is the response the voltage at the input port? Also, you need to specify the passband and stopband frequencies and the attenuation required at these frequencies. Your question is quite vague without having some concrete values.

 

[FvM]

A LC filter needs either a real source or load impedance to implement the intended filter characteristic, but not necessarily both. If Rs is infinite, Rl respectively the real part of the complex load impedance determines the characteristic filter impedance.

 

[Felis_Silvestris]

So.nia,

You might be interested in looking at the "Handbook of Filter Synthesis" by A. Zverev. In that book you'll find normalized filter tables with termination impedances of infinite.