Help My Friend With His Final Year Design Project

AI Thread Summary
A user seeks assistance for a friend's final year design project involving the conversion of a 7th order high pass Butterworth filter from lumped elements to microstrip format, specifically for a cutoff frequency of 3 GHz. The discussion highlights that while high pass filters typically consist of series capacitors and shunt inductors, these can be adapted using transmission lines. Suggestions include replacing shunt inductors with shorted transmission lines and series capacitors with opened transmission lines. Additionally, the Kuroda transformation and Richards transformation are recommended as methods to facilitate this conversion. The conversation emphasizes the challenges of implementing high pass filters with distributed elements but notes that band pass filters with high frequencies are feasible.
Zanjabeel0
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My friend is doing this for his final year design project and has hit a brickwall in terms of understand the actual process. Any help would be appreciated!
 
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Zanjabeel0 said:
My friend is doing this for his final year design project and has hit a brickwall in terms of understand the actual process. Any help would be appreciated!

Welcome to the PF.

Could you provide some context, examples, and a lot more detail for this question please? What do you mean by the term "conversion" in the context of electronic filters?
 
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He designed a 7th order high pass Butterworth filter with lumped elements. He wants to impliment the filter as a microstrip.
He's stuck at the conversion from lumped elements to microstrip. The cut off frequency is 3 Ghz.
 
It is not possible to build a high pass filter with distributed elements.

However, band pass filters with very high top ends are possible and work for most applications.
 
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Hi,

Well, Highpass filters contain series caps and shunt inductors.

shunt inductors can be replaced by shorted transmission lines.

series capacitors can be replaced by opened transmission lines. (but you can't realize this)

replace all lumped with distributed then use kuroda transformation to convert to a microstrip filter with only shunt and series t-line components.

look up RICHARDS TRANSFORMATION and KURODA IDENTITY (MAYBE YOU CAN FIND AN ONLINE PROGRAM)

(Sorry I don't want to spend more time on this but I'll check again later)
 
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