On Thursday, May 7, 2015 at 5:28:23 PM UTC-4, mrob...@att.net wrote:
> dakupoto@gmail.com wrote:
> > We are creating a tool, plain ANSI C based, that will return the
> > ladder LC model filter coefficients for any input filter
> > specification. [...]
> >
> > 1. Is a GUI needed ?
>
> Maybe. The problem with this is that it then becomes very specific to
> a particular OS. If you only want to support Windows, that's fine, but
> you then get to make updates to track what Microsoft does to you.
>
> For a while, Java was supposed to be the solution to cross-platform
> GUIs, but it's sort of going away, these days. Qt is a slightly newer
> solution, but it 1) costs money for commercial use and 2) is a pain in
> the butt to use.
>
> If you make this program, I'd suggest writing the core program as a
> command-line thing that takes input from the command line or a
> configuration file. Then, write a GUI to drive it. This lets people
> use the GUI if they want, or generate their own command lines or
> configuration files to run the program directly. The command-line
> version can also be instantly ported to just about any OS people might
> like to run. Having the command-line version also makes it easier for
> people to automate it with shell scripts, batch files, or equal. They
> could even put it on a server, make an HTML GUI, and use cgi-bin or
> similar to drive it.
>
> Matt Roberds
Thank you very much for your suggestions.
The core program is already working(please
see sample output posted with responses to
another message). As the output filter design
is in SPICE text format, the user is provided
the maximum flexibility to choose parameters
for performance analysis, - signal source,
.AC, .TRAN analysis etc., I do agree with
your comments on both Java and Qt.
Reply by ●May 12, 20152015-05-12
On Friday, May 8, 2015 at 3:39:16 PM UTC-4, Simon S Aysdie wrote:
> On Wednesday, May 6, 2015 at 8:43:11 PM UTC-7, daku...@gmail.com wrote:
> > We are seeking your comments/opinions on
> > the following. We are creating a tool,
> > plain ANSI C based, that will return
> > the ladder LC model filter coefficients
> > for any input filter specification. The
> > input specification would include e.g.,
> > for a low-pass 5th order Chebyschev
> > filter with pass-band ripple of 0.2dB,
> > cut-off frequency of 500 MHz, The
> > output is in SPICE text based input
> > format, specifically a SPICE 'SUBCKT'
> > and consists entirely of discrete
> > components, Our queries are:
> > 1. Is a GUI needed ?
> > 2. Any other points that we might be
> > missing.
>
> A1. Yes
> A2. Yes, because it is not clear why you would bother writing an LC filter design program.
>
> Why? Because FILSYN (S/FILSYN) is the single most powerful filter design tool ever written, particularly for LC filters, and it is now in public domain.
>
> See http://alkeng.com/
>
> It is a bit quirky, can crash, and is not super-easy to use, but it is worth the effort to learn if you ever need anything beyond cookbook designs. FILSYN will not export SPICE lists, but really, that is not so important compared to what it can do.
>
> Output example:
> *** Filsyn *** Filter Program
> <New Passive Filter> 23-Feb-2015 16:43
> 1 +---R---+ 50.000000 ohm
> 3 +---C---+ 300.000000 fF
> 4 | C 41.721050pF
> 5 +---C---+ 11.576369pF
> | .-+.
> 6 | L C 22.000000nH res.frequency
> | `-+' 21.765163pF 230.000000 MHz
> 7 +---C---+ 24.284063pF
> 8 | C 116.237958pF
> +-L-. | 33.000000nH
> 9 | +-C-+ 119.779503pF res. frequency
> +-C-' | 12.763563pF 245.232036 MHz
> 11 +---C---+ 3.000000pF
> 12 | C 32.133646pF
> 13 +---C---+ 4.309304pF
> | .-+.
> 14 | L C 22.000000nH res.frequency
> | `-+' 25.812482pF 211.200000 MHz
> 15 +---C---+ 8.191478pF
> 16 | C 64.289364pF
> +-L-. | 33.000000nH
> 17 | +-C-+ 64.883740pF res. frequency
> +-C-' | 24.826674pF 175.834421 MHz
> 19 +---C---+ 2.500000pF
> 20 | C 40.204568pF
> 21 +---C---+ 1.714493pF
> | .-+.
> 22 | L C 22.000000nH res.frequency
> | `-+' 26.741230pF 207.500000 MHz
> 23 +---C---+ 1.772733pF
> 24 | C 50.028972pF
> +-L-. | 33.000000nH
> 25 | +-C-+ 72.006394pF res. frequency
> +-C-' | 25.996699pF 171.832005 MHz
> 27 +---C---+ 7.371066pF
> 28 | C 236.624737pF
> 29 +---C---+ 2.951900pF
> | .-+.
> 30 | L C 22.000000nH res.frequency
> | `-+' 24.227277pF 218.000000 MHz
> 31 +---C---+ 3.996633pF
> 32 | C 38.733111pF
> 33 +---C---+ 4.000000pF
> 35 +---R---+ 50.000000 ohm
>
> Band-pass filter
> Equal-ripple pass band
> Bandedge loss = 0.500000 dB.
> Lower passband edge frequency = 107.000000 MHz
> Upper passband edge frequency = 194.000000 MHz
> Specified stopband type
> Parametric bandpass
> Multiplicity of zero at zero = 1
> Multiplicity of zero at infinity = 1
> Number of finite transmission zeros = 7
> Overall filter degree = 16
> Transmission zeros
> real part imaginary part
> 0.0000000D+00 8.8500000D+07
> 0.0000000D+00 7.6100000D+07
> 0.0000000D+00 9.2500000D+07
> 0.0000000D+00 2.0750000D+08
> 0.0000000D+00 2.1120000D+08
> 0.0000000D+00 2.1800000D+08
> 0.0000000D+00 2.3000000D+08
> Value of freal = 144.076369 MHz
> Input termination = 50.000000 ohm
> Output termination = 50.000000 ohm
> Requested termination ratio = 1.0000000D+00
>
> --------------
> Try doing the above with anything else. You can't. Only QuikFil comes close on the LC alone basis, and it is a DOS program. BTW, QuickFil is in public domain too. You'd need DOSbox for it.
Dear Sir,
Our package was developed on a multitasking
platform (Linux) and has been easily ported
to Windows 7. On Windows, it can be run under
the native Visual Studio .NET framework, or
the far more convenient Cygwin/MingW framework.
The choice is yours. Our teste so far do not
show ANY of the quirks that you have mentioned
in your posts. The main strength of our package
is that the output is in SPICE format text file
that can easily be used for performance anaylsis,
after making simple modifications to the SPICE
file to add in signal source, analysis directives
(e.g. .AC, .TRAN etc.,) We use Ngspice-26.
The workflow is simple(please check below for
sample input/output). We provide the user two
options to design a band-pass filter.
1. User specifies filter specifications in a
simple text file to be used as input to the
program. This input text file contains
cut-off frequency (low/high Butterworths/
Chebyschev), pass-band ripple (Chebyschev)
filter name(Butterworths/Chebyschev),
bandwidth/center frequency(band-pass filter)
filter type(band-pass, high-pass, low-pass)
and of course filter order
(1|2|3|4|5|6|7|8|9|10)
2. The output is in a SPICE input format text
file.
EXAMPLES:
(A)
To create a 8th irder Butterworths low pass filter, provide the specification in a text
file:
8 950000000 50 bw 0.0 l 0.0 0.0
Program prints name of SPICE format output
file:
Filter order 8
bw8O50950000000l.cir
8th Order Butterworths filter in SPICE format:
.SUBCKT bw8OLP 1 7
* 1 IN
* 7 OUT
R0 1 3 50.00
C0 3 0 1.307390e-12F
L1 3 4 9.307827e-09H
C2 4 0 5.572059e-12F
L3 4 5 1.643173e-08H
C4 5 0 6.572692e-12F
L5 5 6 1.393015e-08H
C6 6 0 3.723131e-12F
L7 6 7 3.268474e-09H
R1 7 0 50.000000
.ENDS
(B)
To create a 9th order Chebyschev high-pass
filter:
9 750000000 50 ch 0.2 h 0.0 0.0
Program prints name of SPICE format output
file:
Filter order 9
ch9O50750000000h.cir
9th Order Chebyschev filter in SPICE format
.SUBCKT ch9OHP 1 7
* 1 IN
* 7 OUT
R0 1 3 50.00
L0 3 0 4.531451e-09H
C1 3 4 6.295026e-13F
L2 4 0 6.484057e-09H
C3 4 5 1.048847e-12F
L4 5 0 8.813392e-09H
C5 5 6 1.348006e-12F
L6 6 0 1.151138e-08H
C7 6 7 1.973626e-12F
L8 7 0 2.867196e-08H
R1 7 0 50.00
.ENDS
Work is still very much in progress.
Reply by Simon S Aysdie●May 10, 20152015-05-10
On Sunday, May 10, 2015 at 8:59:08 AM UTC-7, Simon S Aysdie wrote:
> On Friday, May 8, 2015 at 4:46:32 PM UTC-7, bitrex wrote:
> >
> > Since these things are public domain, it seems the above flaws
> > could be rectified using the appropriate wrapper
> > scripts.
>
> ... The "front-end" scripts drive the FILSYN engine.
>
I should say that one can also drive the main engine by direct entry. Scripts are not required. I do direct entry often. (The filter I showed was designed that way.) The scripting quirk is never seen for direct entry because there is no script to be run.
Reply by Simon S Aysdie●May 10, 20152015-05-10
On Friday, May 8, 2015 at 4:46:32 PM UTC-7, bitrex wrote:
>
> Since these things are public domain, it seems the above flaws
> could be rectified using the appropriate wrapper
> scripts.
For FILSYN, all the "canned" filters (see http://alkeng.com/newmenu.gif) are derived via compiled scripts. If one purchases Winbatch (another vendor), they can develop their own scripts. I have never done that. The "front-end" scripts drive the FILSYN engine.
However, I should mention one of the main quirks, and this will probably annoy people, is that the scripting starts filling out the fields in the GUI and pop-ups for the main engine. If you click in another program while it is doing this, say Excel for example, the script input will then be re-directed to the other program, and start filling in cells. That is not good. It is not "multi-task." You have to wait for it to finish. If the program is run in a VM, then the problem is circumvented.
It is strange, but for me it is easy to look past given what is otherwise offered... for free. It isn't that hard to work around.
The program was written by George Szentirmai. Work on the program began in the '60's.
Reply by bitrex●May 8, 20152015-05-08
Simon S Aysdie <gwhite@ti.com> Wrote in message:
> On Wednesday, May 6, 2015 at 8:43:11 PM UTC-7, daku...@gmail.com wrote:
>> We are seeking your comments/opinions on
>> the following. We are creating a tool,
>> plain ANSI C based, that will return
>> the ladder LC model filter coefficients
>> for any input filter specification. The
>> input specification would include e.g.,
>> for a low-pass 5th order Chebyschev
>> filter with pass-band ripple of 0.2dB,
>> cut-off frequency of 500 MHz, The
>> output is in SPICE text based input
>> format, specifically a SPICE 'SUBCKT'
>> and consists entirely of discrete
>> components, Our queries are:
>> 1. Is a GUI needed ?
>> 2. Any other points that we might be
>> missing.
>
> A1. Yes
> A2. Yes, because it is not clear why you would bother writing an LC filter design program.
>
> Why? Because FILSYN (S/FILSYN) is the single most powerful filter design tool ever written, particularly for LC filters, and it is now in public domain.
>
> See http://alkeng.com/
>
> It is a bit quirky, can crash, and is not super-easy to use, but it is worth the effort to learn if you ever need anything beyond cookbook designs. FILSYN will not export SPICE lists, but really, that is not so important compared to what it can do.
>
> Output example:
> *** Filsyn *** Filter Program
> <New Passive Filter> 23-Feb-2015 16:43
> 1 +---R---+ 50.000000 ohm
> 3 +---C---+ 300.000000 fF
> 4 | C 41.721050pF
> 5 +---C---+ 11.576369pF
> | .-+.
> 6 | L C 22.000000nH res.frequency
> | `-+' 21.765163pF 230.000000 MHz
> 7 +---C---+ 24.284063pF
> 8 | C 116.237958pF
> +-L-. | 33.000000nH
> 9 | +-C-+ 119.779503pF res. frequency
> +-C-' | 12.763563pF 245.232036 MHz
> 11 +---C---+ 3.000000pF
> 12 | C 32.133646pF
> 13 +---C---+ 4.309304pF
> | .-+.
> 14 | L C 22.000000nH res.frequency
> | `-+' 25.812482pF 211.200000 MHz
> 15 +---C---+ 8.191478pF
> 16 | C 64.289364pF
> +-L-. | 33.000000nH
> 17 | +-C-+ 64.883740pF res. frequency
> +-C-' | 24.826674pF 175.834421 MHz
> 19 +---C---+ 2.500000pF
> 20 | C 40.204568pF
> 21 +---C---+ 1.714493pF
> | .-+.
> 22 | L C 22.000000nH res.frequency
> | `-+' 26.741230pF 207.500000 MHz
> 23 +---C---+ 1.772733pF
> 24 | C 50.028972pF
> +-L-. | 33.000000nH
> 25 | +-C-+ 72.006394pF res. frequency
> +-C-' | 25.996699pF 171.832005 MHz
> 27 +---C---+ 7.371066pF
> 28 | C 236.624737pF
> 29 +---C---+ 2.951900pF
> | .-+.
> 30 | L C 22.000000nH res.frequency
> | `-+' 24.227277pF 218.000000 MHz
> 31 +---C---+ 3.996633pF
> 32 | C 38.733111pF
> 33 +---C---+ 4.000000pF
> 35 +---R---+ 50.000000 ohm
>
> Band-pass filter
> Equal-ripple pass band
> Bandedge loss = 0.500000 dB.
> Lower passband edge frequency = 107.000000 MHz
> Upper passband edge frequency = 194.000000 MHz
> Specified stopband type
> Parametric bandpass
> Multiplicity of zero at zero = 1
> Multiplicity of zero at infinity = 1
> Number of finite transmission zeros = 7
> Overall filter degree = 16
> Transmission zeros
> real part imaginary part
> 0.0000000D+00 8.8500000D+07
> 0.0000000D+00 7.6100000D+07
> 0.0000000D+00 9.2500000D+07
> 0.0000000D+00 2.0750000D+08
> 0.0000000D+00 2.1120000D+08
> 0.0000000D+00 2.1800000D+08
> 0.0000000D+00 2.3000000D+08
> Value of freal = 144.076369 MHz
> Input termination = 50.000000 ohm
> Output termination = 50.000000 ohm
> Requested termination ratio = 1.0000000D+00
>
> --------------
> Try doing the above with anything else. You can't. Only QuikFil comes close on the LC alone basis, and it is a DOS program. BTW, QuickFil is in public domain too. You'd need DOSbox for it.
>
Since these things are public domain, it seems the above flaws
could be rectified using the appropriate wrapper
scripts.
--
----Android NewsGroup Reader----
http://usenet.sinaapp.com/
Reply by Phil Hobbs●May 8, 20152015-05-08
On 05/08/2015 03:39 PM, Simon S Aysdie wrote:
> On Wednesday, May 6, 2015 at 8:43:11 PM UTC-7, daku...@gmail.com wrote:
>> We are seeking your comments/opinions on
>> the following. We are creating a tool,
>> plain ANSI C based, that will return
>> the ladder LC model filter coefficients
>> for any input filter specification. The
>> input specification would include e.g.,
>> for a low-pass 5th order Chebyschev
>> filter with pass-band ripple of 0.2dB,
>> cut-off frequency of 500 MHz, The
>> output is in SPICE text based input
>> format, specifically a SPICE 'SUBCKT'
>> and consists entirely of discrete
>> components, Our queries are:
>> 1. Is a GUI needed ?
>> 2. Any other points that we might be
>> missing.
>
> A1. Yes
> A2. Yes, because it is not clear why you would bother writing an LC filter design program.
>
> Why? Because FILSYN (S/FILSYN) is the single most powerful filter design tool ever written, particularly for LC filters, and it is now in public domain.
>
> See http://alkeng.com/
>
> It is a bit quirky, can crash, and is not super-easy to use, but it is worth the effort to learn if you ever need anything beyond cookbook designs. FILSYN will not export SPICE lists, but really, that is not so important compared to what it can do.
>
> Output example:
> *** Filsyn *** Filter Program
> <New Passive Filter> 23-Feb-2015 16:43
> 1 +---R---+ 50.000000 ohm
> 3 +---C---+ 300.000000 fF
> 4 | C 41.721050pF
> 5 +---C---+ 11.576369pF
> | .-+.
> 6 | L C 22.000000nH res.frequency
> | `-+' 21.765163pF 230.000000 MHz
> 7 +---C---+ 24.284063pF
> 8 | C 116.237958pF
> +-L-. | 33.000000nH
> 9 | +-C-+ 119.779503pF res. frequency
> +-C-' | 12.763563pF 245.232036 MHz
> 11 +---C---+ 3.000000pF
> 12 | C 32.133646pF
> 13 +---C---+ 4.309304pF
> | .-+.
> 14 | L C 22.000000nH res.frequency
> | `-+' 25.812482pF 211.200000 MHz
> 15 +---C---+ 8.191478pF
> 16 | C 64.289364pF
> +-L-. | 33.000000nH
> 17 | +-C-+ 64.883740pF res. frequency
> +-C-' | 24.826674pF 175.834421 MHz
> 19 +---C---+ 2.500000pF
> 20 | C 40.204568pF
> 21 +---C---+ 1.714493pF
> | .-+.
> 22 | L C 22.000000nH res.frequency
> | `-+' 26.741230pF 207.500000 MHz
> 23 +---C---+ 1.772733pF
> 24 | C 50.028972pF
> +-L-. | 33.000000nH
> 25 | +-C-+ 72.006394pF res. frequency
> +-C-' | 25.996699pF 171.832005 MHz
> 27 +---C---+ 7.371066pF
> 28 | C 236.624737pF
> 29 +---C---+ 2.951900pF
> | .-+.
> 30 | L C 22.000000nH res.frequency
> | `-+' 24.227277pF 218.000000 MHz
> 31 +---C---+ 3.996633pF
> 32 | C 38.733111pF
> 33 +---C---+ 4.000000pF
> 35 +---R---+ 50.000000 ohm
>
> Band-pass filter
> Equal-ripple pass band
> Bandedge loss = 0.500000 dB.
> Lower passband edge frequency = 107.000000 MHz
> Upper passband edge frequency = 194.000000 MHz
> Specified stopband type
> Parametric bandpass
> Multiplicity of zero at zero = 1
> Multiplicity of zero at infinity = 1
> Number of finite transmission zeros = 7
> Overall filter degree = 16
> Transmission zeros
> real part imaginary part
> 0.0000000D+00 8.8500000D+07
> 0.0000000D+00 7.6100000D+07
> 0.0000000D+00 9.2500000D+07
> 0.0000000D+00 2.0750000D+08
> 0.0000000D+00 2.1120000D+08
> 0.0000000D+00 2.1800000D+08
> 0.0000000D+00 2.3000000D+08
> Value of freal = 144.076369 MHz
> Input termination = 50.000000 ohm
> Output termination = 50.000000 ohm
> Requested termination ratio = 1.0000000D+00
>
> --------------
> Try doing the above with anything else. You can't. Only QuikFil comes close on the LC alone basis, and it is a DOS program. BTW, QuickFil is in public domain too. You'd need DOSbox for it.
>
Awesome!
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Simon S Aysdie●May 8, 20152015-05-08
On Wednesday, May 6, 2015 at 8:43:11 PM UTC-7, daku...@gmail.com wrote:
> We are seeking your comments/opinions on
> the following. We are creating a tool,
> plain ANSI C based, that will return
> the ladder LC model filter coefficients
> for any input filter specification. The
> input specification would include e.g.,
> for a low-pass 5th order Chebyschev
> filter with pass-band ripple of 0.2dB,
> cut-off frequency of 500 MHz, The
> output is in SPICE text based input
> format, specifically a SPICE 'SUBCKT'
> and consists entirely of discrete
> components, Our queries are:
> 1. Is a GUI needed ?
> 2. Any other points that we might be
> missing.
A1. Yes
A2. Yes, because it is not clear why you would bother writing an LC filter design program.
Why? Because FILSYN (S/FILSYN) is the single most powerful filter design tool ever written, particularly for LC filters, and it is now in public domain.
See http://alkeng.com/
It is a bit quirky, can crash, and is not super-easy to use, but it is worth the effort to learn if you ever need anything beyond cookbook designs. FILSYN will not export SPICE lists, but really, that is not so important compared to what it can do.
Output example:
*** Filsyn *** Filter Program
<New Passive Filter> 23-Feb-2015 16:43
1 +---R---+ 50.000000 ohm
3 +---C---+ 300.000000 fF
4 | C 41.721050pF
5 +---C---+ 11.576369pF
| .-+.
6 | L C 22.000000nH res.frequency
| `-+' 21.765163pF 230.000000 MHz
7 +---C---+ 24.284063pF
8 | C 116.237958pF
+-L-. | 33.000000nH
9 | +-C-+ 119.779503pF res. frequency
+-C-' | 12.763563pF 245.232036 MHz
11 +---C---+ 3.000000pF
12 | C 32.133646pF
13 +---C---+ 4.309304pF
| .-+.
14 | L C 22.000000nH res.frequency
| `-+' 25.812482pF 211.200000 MHz
15 +---C---+ 8.191478pF
16 | C 64.289364pF
+-L-. | 33.000000nH
17 | +-C-+ 64.883740pF res. frequency
+-C-' | 24.826674pF 175.834421 MHz
19 +---C---+ 2.500000pF
20 | C 40.204568pF
21 +---C---+ 1.714493pF
| .-+.
22 | L C 22.000000nH res.frequency
| `-+' 26.741230pF 207.500000 MHz
23 +---C---+ 1.772733pF
24 | C 50.028972pF
+-L-. | 33.000000nH
25 | +-C-+ 72.006394pF res. frequency
+-C-' | 25.996699pF 171.832005 MHz
27 +---C---+ 7.371066pF
28 | C 236.624737pF
29 +---C---+ 2.951900pF
| .-+.
30 | L C 22.000000nH res.frequency
| `-+' 24.227277pF 218.000000 MHz
31 +---C---+ 3.996633pF
32 | C 38.733111pF
33 +---C---+ 4.000000pF
35 +---R---+ 50.000000 ohm
Band-pass filter
Equal-ripple pass band
Bandedge loss = 0.500000 dB.
Lower passband edge frequency = 107.000000 MHz
Upper passband edge frequency = 194.000000 MHz
Specified stopband type
Parametric bandpass
Multiplicity of zero at zero = 1
Multiplicity of zero at infinity = 1
Number of finite transmission zeros = 7
Overall filter degree = 16
Transmission zeros
real part imaginary part
0.0000000D+00 8.8500000D+07
0.0000000D+00 7.6100000D+07
0.0000000D+00 9.2500000D+07
0.0000000D+00 2.0750000D+08
0.0000000D+00 2.1120000D+08
0.0000000D+00 2.1800000D+08
0.0000000D+00 2.3000000D+08
Value of freal = 144.076369 MHz
Input termination = 50.000000 ohm
Output termination = 50.000000 ohm
Requested termination ratio = 1.0000000D+00
--------------
Try doing the above with anything else. You can't. Only QuikFil comes close on the LC alone basis, and it is a DOS program. BTW, QuickFil is in public domain too. You'd need DOSbox for it.
Reply by JM●May 8, 20152015-05-08
On 07/05/2015 22:27, mroberds@att.net wrote:
> dakupoto@gmail.com wrote:
>> We are creating a tool, plain ANSI C based, that will return the
>> ladder LC model filter coefficients for any input filter
>> specification. [...]
>>
>> 1. Is a GUI needed ?
>
> Maybe. The problem with this is that it then becomes very specific to
> a particular OS. If you only want to support Windows, that's fine, but
> you then get to make updates to track what Microsoft does to you.
>
> For a while, Java was supposed to be the solution to cross-platform
> GUIs, but it's sort of going away, these days. Qt is a slightly newer
> solution, but it 1) costs money for commercial use and 2) is a pain in
> the butt to use.
>
> If you make this program, I'd suggest writing the core program as a
> command-line thing that takes input from the command line or a
> configuration file. Then, write a GUI to drive it. This lets people
> use the GUI if they want, or generate their own command lines or
> configuration files to run the program directly. The command-line
> version can also be instantly ported to just about any OS people might
> like to run. Having the command-line version also makes it easier for
> people to automate it with shell scripts, batch files, or equal. They
> could even put it on a server, make an HTML GUI, and use cgi-bin or
> similar to drive it.
>
> Matt Roberds
>
Qt is free for commercial use if your program is not statically linked
with Qt code.
Reply by bitrex●May 7, 20152015-05-07
John Larkin <jlarkin@highlandtechnology.com> Wrote in message:
> On Thu, 7 May 2015 04:39:02 -0500, "Tim Williams"
> <tiwill@seventransistorlabs.com> wrote:
>
>>1. Sure -- might show graphs, play with parts values, etc.
>>
>>Basically, this: http://www-users.cs.york.ac.uk/~fisher/lcfilter/
>>
>>Bonus points for being able to specify real parts (i.e., finite Q, and/or
>>parasitic L/C).
>>
>>2. Even better to start with a prototype design (such as one of the
>>standard filter types), and adjust node and branch subcircuits. AADE
>>Filter Design allows this (more or less, but it doesn't seem to have a
>>"remove stage" function, bizarrely).
>>
>>Bonus points (and by "points", I mean real monetary bucks -- even I'd pay
>>for this!) for parts value optimizations -- best fit or bounded constraint
>>to a frequency (and/or phase or group delay) curve, using real valued
>>components, or limited to selections from a database (e.g., E12 values,
>>inventory stock). Plotting first order derivatives would be cool too (not
>>directly, but as part of evaluating parts value sensitivity).
>>
>>I've heard of such features in super expensive suites, but they're so
>>cryptic on interface and capability, not to mention price (if you have to
>>ask?..), that I have no problem plodding along with meager tools without
>>them.
>>
>>Tim
>
> We bought the Nuhertz LC filter program. I think it cost around $1000
> and paid for itself quickly. It does a zillion different filter forms,
> many that we'd never heard of, and can design a filter using standard
> L and C values. It works really well, but the user interface is
> clunky. The guy who runs Nuhertz is brilliant and sort of crabby.
>
> Somebody could make some money buying that and running solutions for a
> fee. Few people need to design LC filters full-time.
>
> I use the free Filterpro for active filters. V2 seems to be better
> than later editions.
>
>
> --
>
> John Larkin Highland Technology, Inc
> picosecond timing laser drivers and controllers
>
> jlarkin att highlandtechnology dott com
> http://www.highlandtechnology.com
>
>
Do you still need a thingie that generates equivalent gate drive
RLC ladder networks from MOSFET S parameters? I had some
ideas.
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Reply by bitrex●May 7, 20152015-05-07
dakupoto@gmail.com Wrote in message:
> We are seeking your comments/opinions on
> the following. We are creating a tool,
> plain ANSI C based, that will return
> the ladder LC model filter coefficients
> for any input filter specification. The
> input specification would include e.g.,
> for a low-pass 5th order Chebyschev
> filter with pass-band ripple of 0.2dB,
> cut-off frequency of 500 MHz, The
> output is in SPICE text based input
> format, specifically a SPICE 'SUBCKT'
> and consists entirely of discrete
> components, Our queries are:
> 1. Is a GUI needed ?
> 2. Any other points that we might be
> missing.
>
> All comments/opinions are welcome.
> Thanks in advance,
>
>
Why would you use plain ANSI C to write a tool like this? That
seems pathological.
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