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Highpass Filter Using Optimum Distributed

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hellotoke

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Looking to find how to change the ripple of the Optimum Distributed Highpass Filter Design in J. S. Hong and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications. Wiley. New York, 2001.To a ripple of like 0.2 maybe
 
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Textbook quoted in post #1 explains how to calculate equal ripple (Chebychev) filter parameters for any order and ripple specification. High-pass transformation has to be applied to synthesize high-pass.
 
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I'm not sure if you want to learn the theory, or the math, use tables, simulate the LC values or just realize an optimal filter to meet specs. **

Normally I choose the passband and stopband parameters for attenuation and group delay then decide how to achieve it.

Chebychev filters are "ideal" for max slope vs ripple but suffer from large group delay swings in the passband which are not ideal. But when ripple is reduced to 0 dB you end up with a Butterworth.

Let me assume the last option. **
Here I simulated an 8th 1GHz HPF at 0.1 dB ripple then adjusted to 0.2 dB. The attenuation improvement at 1 octave down is only -2 dB to -76.6 dB at fo/2.

The microstrip might be computed for a given substrate from the LC values.

1728010890468.png



my simulation link.

1728011374018.png
 
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D.A.(Tony)Stewart said:
I'm not sure if you want to learn the theory, or the math, use tables, simulate the LC values or just realize an optimal filter to meet specs. **

Normally I choose the passband and stopband parameters for attenuation and group delay then decide how to achieve it.

Chebychev filters are "ideal" for max slope vs ripple but suffer from large group delay swings in the passband which are not ideal. But when ripple is reduced to 0 dB you end up with a Butterworth.

Let me assume the last option. **
Here I simulated an 8th 1GHz HPF at 0.1 dB ripple then adjusted to 0.2 dB. The attenuation improvement at 1 octave down is only -2 dB to -76.6 dB at fo/2.

The microstrip might be computed for a given substrate from the LC values.

View attachment 194394


my simulation link.

View attachment 194396
Click to expand...
Looking how to get the admittance values for such a filter as from the book.
--- Updated ---

FvM said:
Textbook quoted in post #1 explains how to calculate equal ripple (Chebychev) filter parameters for any order and ripple specification. High-pass transformation has to be applied to synthesize high-pass.
Click to expand...
It has a diffrent filtering function to a chebyschev filter,so the admittance values are diffrent.
--- Updated ---

FvM said:
Textbook quoted in post #1 explains how to calculate equal ripple (Chebychev) filter parameters for any order and ripple specification. High-pass transformation has to be applied to synthesize high-pass.
Click to expand...
It has a diffrent filtering function to a chebyschev filter,so the admittance values are diffrent.
 
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hellotoke said:
It has a diffrent filtering function to a chebyschev filter,so the admittance values are diffrent.
Click to expand...
The only information you have been yet given is the reference to Optimum Distributed Highpass Filter Design book. The respective example on page 165f is Chebychev high pass, the design is based on Chebychev polynominals. But as stated above, we are missing your specification.
 
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D.A.(Tony)Stewart said:
From theYouTube video he explains some of the equations and how to interpolate, but not how to expand to an eighth order. You will notice that the symmetry excludes odd order filters

He also has a new book which you may need to purchase. https://www.google.com/search?q=optimal distributed generation allocation and sizing &ie=utf-8&oe=utf-8&client=fire
D.A.(Tony)Stewart said:
What specs? If none keep keeping till you have some.
Click to expand...
I need it for any order ,so higher order and mostly any ripple and Fc,so actually asking how to synthesis it
Click to expand...
 
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sorry wrong link search


Now restart with some realizable design specs and desired analysis to verify.

Better Link
www.google.ca

Microstrip Filters for RF / Microwave Applications

Advanced, specialized coverage of microstrip filter design Microstrip Filters for RF/Microwave Applications is the only professional reference focusing solely on microstrip filters. It offers a unique and comprehensive treatment of filters based on the microstrip structure and includes full...
www.google.ca

I did not find "Lagrang" anywhere in the book.

see how the dominant resonant frequencies he defines with sidebands using impedance/ admittance analysis.
1728180969222.png
 
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Anyone else?the advice I gotten here is wrong :rolleyes:.but thats forums for you
 
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I think the consensus is Lagrangian methods alone (or even at all) will not help you design a filter until you have desired properties somewhat defined by some category like the shape of amplitude, phase, group delay for the passband and stopband.

You need to research more about filter design from Zverev and coupled oscillators to understand your question is unanswerable.

Now keep your hand raised for the Professor until the oscillation stops from this mechanical version of a coupled dual resonator.

Please read my tagline below which only applies to people who have had bad experiences from forums getting succinct accurate responses.
 
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