Filter Designer

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Electronman

New Member

• Dec 29, 2009

• #1

Hello there,

I need to design a High pass filter, Whats The best Software to do so?

Thanks

 

crutschow

Well-Known Member

Most Helpful Member

• Dec 29, 2009

• #2

What is the frequency range; active or passive filter?

 

MikeMl

Well-Known Member

Most Helpful Member

• Dec 29, 2009

• #3

Recent thread about filters

 

audioguru

Well-Known Member

Most Helpful Member

• Dec 29, 2009

• #4

You would expect when somebody asks about a highpass filter, the cutoff frequency and slope would be mentioned. Maybe even a mention about what it will be used for.

 

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Electronman

New Member

• Dec 31, 2009

• #5

Well, I want it for low frequencies (almost 100kHz is good).
I want and prefer Active ones (Can somebody tells me which one is better? Active or passive?)
I have used "FilterPro V2.0" but unfortunetely it is able to make 10 orders filters MAX. I need 12 to 14 orders to remove the lower sideband of my modulator yet let the Upper one to passes. So I guess the higher order the better sharpness I'll get, right? Unfortunetely the lower and the upper sideband have just 200 to 300 Hz difference at some states at 40kHz center carrier.

 

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Electronman

New Member

• Jan 1, 2010

• #6

Any high order designer one??
So Which ones of filter designer softwares do you guys prefer to use?

 

MikeMl

Well-Known Member

Most Helpful Member

• Jan 1, 2010

• #7

Why not combine two filters: low-pass and notch?

Also, if you want to do it using just low-pass, then use FilterPro to design a 6 or 8 pole low-pass filter, with a bit higher-corner frequency than you ultimately want. By cascading two of them, the resulting filter will have a lower cutoff freq, and a sharper rolloff. Enter the design into LTSpice, and sweep the cascaded filter. You might have to try a couple of iterations, but you will wind up with a ~12 to 14 pole filter...

 

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Electronman

New Member

• Jan 1, 2010

• #8

I Want a High pass Filter, how Does a low pass and notch filter are connected so that make a high pass filter? What's the benefit?
Why cascading and not try to find a filter software which is able to design more orders filters than Filter pro (which allows just 10 orders)?

Does every body know how many of orders I need for the frequencies I mentioned above?

 

MikeMl

Well-Known Member

Most Helpful Member

• Jan 2, 2010

• #9

Electronman said:

I Want a High pass Filter, how Does a low pass and notch filter are connected so that make a high pass filter? What's the benefit?
Why cascading and not try to find a filter software which is able to design more orders filters than Filter pro (which allows just 10 orders)?...?

Click to expand...

Sorry, I forgot to look back 7 posts

I'm guessing that you think you need 14poles to get a steep rolloff. If that is the goal, then combine a notch with high-pass. Cascading these two will give a very steep rolloff with fewer opamp stages.

You can buy filter design software which does more poles than FilterPro.

 

Last edited: Jan 2, 2010