Cascaded filters and ladder filters

[jeffreycheng]

Hi,
Can anybody told me the defination of cascaded filters and ladder filters. What is the difference between them. is there any documents that dicussed about them.
Thanks very much.

 

[LvW]

Hi,
Can anybody told me the defination of cascaded filters and ladder filters. What is the difference between them. is there any documents that dicussed about them.
Thanks very much.

Yes, there are some documents. I am sure, you will be not surprised to read, that each textbooks which covers filter theory and circuits (and there are many!!) explains these differences.
In short:
* for cascaded design, the transfer function is split into severals parts of second order leading to a design which consists of a series connection of second order stages.
* ladder design: The transfer function leads to a LC-ladder topology which then is transferred to an active structure without inductances (leap frog design or FDNR concept)

 

[jeffreycheng]

Thanks for your imformation.
It seems I have wasted my life in the univerty.
Could you please give me a name of the reference book?
Thanks.

 

[keith1200rs]

The free version of Nuhertz has some useful comparisons in the help files. **broken link removed** unfortunately the free version will only design up to 3 poles.

Keith.

 

[LvW]

...........
It seems I have wasted my life in the univerty.
..........

I disagree - perhaps you have wasted some TIME, but not your life!
Concerning books, I recommend to search via google or amazon, and you will find at least 20 book titles dealing with filters (Huelsman, Lindquist, Ghausi, Laker, Bruton, Natarajan, Lam, Moschytz,...just to mention some of them).

 

[keith1200rs]

It is not wasted time. Hopefully you learnt something which is then the basis for the next 50 years of continued learning. Not everything you learn (or are taught) is what you wanted to know, but you don't know that until you know it, if you see what I mean!

Keith.

 

[LvW]

It is not wasted time. Hopefully you learnt something which is then the basis for the next 50 years of continued learning.
...........
Keith.

Yes, keith, I agree. And the most important thing is: I am sure, you have learnt how to gather proper information and facts - and how to combine them with the aim to solve problems. That's much more important than to learn "only" rules and formulas.