> On Saturday, March 17, 2018 at 10:30:00 PM UTC+5:30, Phil Hobbs wrote:
>> On 03/17/18 02:57, dakupoto@gmail.com wrote:
>>> On Friday, March 16, 2018 at 10:05:40 PM UTC+5:30, Jim Thompson wrote:
>>>> On Fri, 16 Mar 2018 04:50:54 -0700 (PDT), dakupoto@gmail.com wrote:
>>>>
>>>>> On Friday, March 16, 2018 at 3:42:04 AM UTC+5:30, Jim Thompson wrote:
>>>> [snip]
>>>>>>>> Schematic? What does "wideband" mean? fL, fH, dB's?
>>>>>>>>
>>>>>>>> ...Jim Thompson
>>>>>> [snip]
>>>>>>>
>>>> [snip]
>>>>>>>
>>>>>>> Any hints/suggestions would be very helpful.
>>>>>>> Thanks in advance.
>>>>>>
>>>>>> Gozinta/gozouta specification? You're exhibiting the standard failure
>>>>>> here of thinking you can force what you think the solution should be
>>>>>> rather than specifying the desired results... sort like the "Searching
>>>>>> for an Op-Amp" fiasco >:-}
>>>>>>
>>>>>> (I actually have symbols in my spice library: gozinta, gozouta, and
>>>>>> gozbi... prettied-up _small_ port symbols ;-)
>>>>>>
>>>> [snip]
>>>>
>>>> NGspice, HSpice noted. LTspice requires all kinds of extra steps to
>>>> get to a numerically analyzable set of data points
>>>>
>>>> Unless HSpice has been recently neutered, I'd hazard a guess that it's
>>>> .PRINT statement will produce a table in the .OUT file that can pasted
>>>> into Excel or a curve-fitting program (which is what I mostly use it
>>>> for... for behavioral modeling ;-)
>>>>
>>>>>
>>>>> I am not forcing anything on anyone. Please read my previous response to your previous message.
>>>>
>>>> Then I missed that post... perhaps during my surgery yesterday?
>>>>
>>>> I'd like an answer to "What does "wideband" mean? fL, fH, dB's?"
>>>>
>>>> If your desired LP corner is > 2*pi*Rload/Lload you've got problems,
>>>> if < 2*pi*Rload/Lload, piece-a-cake.
>>>>
>>>> A definitive statement of the problem will produce definitive answers,
>>>> otherwise blather and bloviations >:-}
>>>>
>>>> ...Jim Thompson
>>>> --
>>>> | James E.Thompson | mens |
>>>> | Analog Innovations | et |
>>>> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
>>>> | STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
>>>> | Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
>>>> | E-mail Icon at http://www.analog-innovations.com | 1962 |
>>>>
>>>> Understanding is a fountain of life to one who has it,
>>>> But the instruction of fools is folly. Proverbs 16:22
>>>
>>> So, let us start with the LP corner < 2.0*PI*RLoad*Lload,
>>>
>>> What would be the solution ?
>>>
>>
>> There's a tradeoff between the log of the return loss and
>> bandwidth--it's a theorem of Bode's, so of course it's called the
>> Fano-Bode limit. See e.g.
>>
>> http://www.ece.ucsb.edu/~long/ece145a/zmatch.pdf
>>
>> Cheers
>>
>> Phil Hobbs
>> --
>> Dr Philip C D Hobbs
>> Principal Consultant
>> ElectroOptical Innovations LLC / Hobbs ElectroOptics
>> Optics, Electro-optics, Photonics, Analog Electronics
>> Briarcliff Manor NY 10510
>>
>> http://electrooptical.net
>> http://hobbs-eo.com
>
> So true. In fact, all approaches to broadband impedance matching are governed by the Bode-Fano
> inequalities. The solution that I re-discovered(
> I had worked on a very similar problem about three
> years ago) is the Zobel network, that effectively
> "converts" a series R-C or series R-L load to a
> resistor -- used to impedance match signals to
> gates of RF/microwave FETs.
>
Yup, a 1-pole diplexer. There are more complicated ones.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttps://hobbs-eo.com
Reply by ●March 19, 20182018-03-19
On Saturday, March 17, 2018 at 10:30:00 PM UTC+5:30, Phil Hobbs wrote:
> On 03/17/18 02:57, dakupoto@gmail.com wrote:
> > On Friday, March 16, 2018 at 10:05:40 PM UTC+5:30, Jim Thompson wrote:
> >> On Fri, 16 Mar 2018 04:50:54 -0700 (PDT), dakupoto@gmail.com wrote:
> >>
> >>> On Friday, March 16, 2018 at 3:42:04 AM UTC+5:30, Jim Thompson wrote:
> >> [snip]
> >>>>>> Schematic? What does "wideband" mean? fL, fH, dB's?
> >>>>>>
> >>>>>> ...Jim Thompson
> >>>> [snip]
> >>>>>
> >> [snip]
> >>>>>
> >>>>> Any hints/suggestions would be very helpful.
> >>>>> Thanks in advance.
> >>>>
> >>>> Gozinta/gozouta specification? You're exhibiting the standard failure
> >>>> here of thinking you can force what you think the solution should be
> >>>> rather than specifying the desired results... sort like the "Searching
> >>>> for an Op-Amp" fiasco >:-}
> >>>>
> >>>> (I actually have symbols in my spice library: gozinta, gozouta, and
> >>>> gozbi... prettied-up _small_ port symbols ;-)
> >>>>
> >> [snip]
> >>
> >> NGspice, HSpice noted. LTspice requires all kinds of extra steps to
> >> get to a numerically analyzable set of data points
> >>
> >> Unless HSpice has been recently neutered, I'd hazard a guess that it's
> >> .PRINT statement will produce a table in the .OUT file that can pasted
> >> into Excel or a curve-fitting program (which is what I mostly use it
> >> for... for behavioral modeling ;-)
> >>
> >>>
> >>> I am not forcing anything on anyone. Please read my previous response to your previous message.
> >>
> >> Then I missed that post... perhaps during my surgery yesterday?
> >>
> >> I'd like an answer to "What does "wideband" mean? fL, fH, dB's?"
> >>
> >> If your desired LP corner is > 2*pi*Rload/Lload you've got problems,
> >> if < 2*pi*Rload/Lload, piece-a-cake.
> >>
> >> A definitive statement of the problem will produce definitive answers,
> >> otherwise blather and bloviations >:-}
> >>
> >> ...Jim Thompson
> >> --
> >> | James E.Thompson | mens |
> >> | Analog Innovations | et |
> >> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
> >> | STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
> >> | Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
> >> | E-mail Icon at http://www.analog-innovations.com | 1962 |
> >>
> >> Understanding is a fountain of life to one who has it,
> >> But the instruction of fools is folly. Proverbs 16:22
> >
> > So, let us start with the LP corner < 2.0*PI*RLoad*Lload,
> >
> > What would be the solution ?
> >
>
> There's a tradeoff between the log of the return loss and
> bandwidth--it's a theorem of Bode's, so of course it's called the
> Fano-Bode limit. See e.g.
>
> http://www.ece.ucsb.edu/~long/ece145a/zmatch.pdf
>
> Cheers
>
> Phil Hobbs
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC / Hobbs ElectroOptics
> Optics, Electro-optics, Photonics, Analog Electronics
> Briarcliff Manor NY 10510
>
> http://electrooptical.net
> http://hobbs-eo.com
So true. In fact, all approaches to broadband impedance matching are governed by the Bode-Fano
inequalities. The solution that I re-discovered(
I had worked on a very similar problem about three
years ago) is the Zobel network, that effectively
"converts" a series R-C or series R-L load to a
resistor -- used to impedance match signals to
gates of RF/microwave FETs.
Reply by ●March 19, 20182018-03-19
On Thursday, March 15, 2018 at 11:01:09 AM UTC+5:30, Jasen Betts wrote:
> On 2018-03-14, dakupoto@gmail.com <dakupoto@gmail.com> wrote:
> > Could some electronics guru please help ? I am running some SPICE
> > simulations on wideband impedance matching of the following setup.
> > The source and load resistances are equal
> > The source is a pure resistor
> > Yhe load consists of a resistor(same value as source resistor) and
> > a series inductor
> > The matching network is a 6th order low pass filter with a
> > series inductor as the last element.
> > The RMS input power and the RMS output power are measured.
> > The ratio RMS output power/RMS input power is very low, indicating
> > poor matching and large invident signal reflection. How would the
> > load inductor be bullified in a physically realizable way ? All
> > hints/suggestions are welcome. Thanks in advance.
>
> are you looking for a Zobel Network?
> https://en.wikipedia.org/wiki/Zobel_network
>
> --
> This email has not been checked by half-arsed antivirus software
Thanks for jogging my memory. I had worked on a
similar design issue about three years ago, derived the simple expressions for the Zobel
network, and then completely forgotten about it.
Reply by ●March 19, 20182018-03-19
On Saturday, March 17, 2018 at 9:24:08 PM UTC+5:30, John Larkin wrote:
> On Sat, 17 Mar 2018 00:09:28 -0700 (PDT), dakupoto@gmail.com wrote:
>
> >On Friday, March 16, 2018 at 8:27:40 PM UTC+5:30, John Larkin wrote:
> >> On Fri, 16 Mar 2018 04:12:22 -0700 (PDT), dakupoto@gmail.com wrote:
> >>
> >> >On Thursday, March 15, 2018 at 9:27:10 PM UTC+5:30, John Larkin wrote:
> >> >> On Thu, 15 Mar 2018 05:30:38 -0700 (PDT), dakupoto@gmail.com wrote:
> >> >>
> >> >> >On Thursday, March 15, 2018 at 5:15:38 AM UTC+5:30, Jim Thompson wrote:
> >> >> >> On Tue, 13 Mar 2018 23:39:57 -0700 (PDT), dakupoto@gmail.com wrote:
> >> >> >>
> >> >> >> >Could some electronics guru please help ? I am running some SPICE
> >> >> >> >simulations on wideband impedance matching of the following setup.
> >> >> >> >The source and load resistances are equal
> >> >> >> >The source is a pure resistor
> >> >> >> >Yhe load consists of a resistor(same value as source resistor) and
> >> >> >> >a series inductor
> >> >> >> >The matching network is a 6th order low pass filter with a
> >> >> >> >series inductor as the last element.
> >> >> >> >The RMS input power and the RMS output power are measured.
> >> >> >> >The ratio RMS output power/RMS input power is very low, indicating
> >> >> >> >poor matching and large invident signal reflection. How would the
> >> >> >> >load inductor be bullified in a physically realizable way ? All
> >> >> >> >hints/suggestions are welcome. Thanks in advance.
> >> >> >> >
> >> >> >> >
> >> >> >>
> >> >> >> Schematic? What does "wideband" mean? fL, fH, dB's?
> >> >> >>
> >> >> >> ...Jim Thompson
> >> >> >> --
> >> >> >> | James E.Thompson | mens |
> >> >> >> | Analog Innovations | et |
> >> >> >> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
> >> >> >> | STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
> >> >> >> | Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
> >> >> >> | E-mail Icon at http://www.analog-innovations.com | 1962 |
> >> >> >>
> >> >> >> It's what you learn, after you know it all, that counts.
> >> >> >
> >> >> >The SPICE netlist is listed below:
> >> >> >Low pass filter impedance matching
> >> >> >* Identical load source resistance
> >> >> >* and series load inductor
> >> >> >
> >> >> >.PARAMS FREQ=3.453144e+08 LLIM=1.726572e+07 HLIM=6.043003e+08 AMPL=10
> >> >> >
> >> >> >.SUBCKT LPFILT 1 2
> >> >> >* 1 IN
> >> >> >* 2 OUT
> >> >> >C1 1 0 2.353875e-10
> >> >> >L2 1 3 6.431530e-10
> >> >> >C3 3 0 8.787569e-10
> >> >> >L4 3 4 8.791318e-10
> >> >> >C5 4 0 6.441774e-10
> >> >> >L6 4 2 2.367870e-10
> >> >> >.ENDS
> >> >> >
> >> >> >* COMMENT OUT TRANSIENT ANALYSIS
> >> >> >* TO RUN AC ANALYSIS AND VICE-VERSA
> >> >> >
> >> >> >LLOAD 6 7 1.200000e-08
> >> >> >LCOMP 5 6 1.772026e-11
> >> >> >RSRC 1 2 50.000000
> >> >> >RLOAD 7 0 50.000000
> >> >> >XLP 3 4 LPFILT
> >> >> >VTST0 2 3 DC 0.0 AC 0.0
> >> >> >VTST1 4 5 DC 0.0 AC 0.0
> >> >> >
> >> >> >* FOR TRANSIENT ANALYSIS
> >> >> >VSIG 1 0 DC 0.005 SIN(0 {AMPL} {FREQ} 0 0 0)
> >> >> >* FOR AC(SMALL SIGNAL) ANALYSIS
> >> >> >VSIG 1 0 DC 0.005 AC {AMPL})
> >> >> >
> >> >> >.OPTIONS METHOD=GEAR NOPAGE RELTOL=1m MINBREAK=5ps
> >> >> >.IC
> >> >> >.TRAN 75.0ns 500.0us 50.0ns UIC
> >> >> >* INPUT/SOURCE SIDE
> >> >> >.PRINT TRAN V(3) I(VTST0)
> >> >> >* LOAD/OUTPUT SIDE
> >> >> >.PRINT TRAN V(4) I(VTST1)
> >> >> >
> >> >> >.AC LIN 20000 {LLIM} {HLIM}
> >> >> >.PRINT AC V(5)
> >> >> >** FOR REFLECTION COEFFICIENT ETC.,
> >> >> >.PRINT AC V(2)
> >> >> >.END
> >> >> >
> >> >> >Any hints/suggestions would be very helpful.
> >> >> >Thanks in advance.
> >> >>
> >> >> Can you post a visible schematic?
> >> >>
> >> >> I still don't know what you are trying to do.
> >> >>
> >> >> I've done some work lately on one-end-reflectionless lowpass filters,
> >> >> based on Jeroen's concepts. Mini-Circuits has some interesting new
> >> >> symmetric filters, both-ends-reflectionless.
> >> >>
> >> >>
> >> >> --
> >> >>
> >> >> John Larkin Highland Technology, Inc
> >> >>
> >> >> lunatic fringe electronics
> >> >
> >> >I am afraid I do not have a visible schematic. I use HSpice at work, and Ngspice at home, both of which use the text input. It is sometimes bothersome to enter a new large netlist, but
> >> >editing is very easy.
> >>
> >> Just a sketch would help. I don't know what you are trying to do.
> >>
> >> LT Spice lets you draw a schematic instantly. Typing (and reading!)
> >> netlists is really old-fashioned.
> >>
> >>
> >>
> >>
> >> --
> >>
> >> John Larkin Highland Technology, Inc
> >>
> >> lunatic fringe electronics
> >
> >The setup is simple :
> >A signal source feeds a low pass ladder matching network, e.g., of order 6. The source impedance is purely resistive (NO source reactance). The load is a resistor in series with an inductor. The load and source resistors have the same value
> >So how do I compensate for the frequency dependent load inductor ?
>
> I think the answer is trivial, but if you refuse to show a sketch, I
> refuse to talk about it.
>
>
> --
>
> John Larkin Highland Technology, Inc
>
> lunatic fringe electronics
The solution is indeed trivial -- Zobel network.
Funny thing is that I had workrf on a similar
problem about three years ago, derived the simple
expressions for this simple but very useful
sub-circuit, and then completely forgotten about it. The frequency response of a Zobel network is
flat over any frequency range of choice, thereby
"converting" a series R-L or series R-C load to
a resistor.
Reply by Jim Thompson●March 17, 20182018-03-17
On Sat, 17 Mar 2018 09:40:55 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>On Fri, 16 Mar 2018 23:57:38 -0700 (PDT), dakupoto@gmail.com wrote:
>
>>On Friday, March 16, 2018 at 10:05:40 PM UTC+5:30, Jim Thompson wrote:
>>> On Fri, 16 Mar 2018 04:50:54 -0700 (PDT), dakupoto@gmail.com wrote:
>>>
>>> >On Friday, March 16, 2018 at 3:42:04 AM UTC+5:30, Jim Thompson wrote:
>>> [snip]
>>> >> >> Schematic? What does "wideband" mean? fL, fH, dB's?
>>> >> >>
>>> >> >> ...Jim Thompson
>>> >> [snip]
>>> >> >
>>> [snip]
>>> >> >
>>> >> >Any hints/suggestions would be very helpful.
>>> >> >Thanks in advance.
>>> >>
>>> >> Gozinta/gozouta specification? You're exhibiting the standard failure
>>> >> here of thinking you can force what you think the solution should be
>>> >> rather than specifying the desired results... sort like the "Searching
>>> >> for an Op-Amp" fiasco >:-}
>>> >>
>>> >> (I actually have symbols in my spice library: gozinta, gozouta, and
>>> >> gozbi... prettied-up _small_ port symbols ;-)
>>> >>
>>> [snip]
>>>
>>> NGspice, HSpice noted. LTspice requires all kinds of extra steps to
>>> get to a numerically analyzable set of data points
>>>
>>> Unless HSpice has been recently neutered, I'd hazard a guess that it's
>>> .PRINT statement will produce a table in the .OUT file that can pasted
>>> into Excel or a curve-fitting program (which is what I mostly use it
>>> for... for behavioral modeling ;-)
>>>
>>> >
>>> >I am not forcing anything on anyone. Please read my previous response to your previous message.
>>>
>>> Then I missed that post... perhaps during my surgery yesterday?
>>>
>>> I'd like an answer to "What does "wideband" mean? fL, fH, dB's?"
>>>
>>> If your desired LP corner is > 2*pi*Rload/Lload you've got problems,
>>> if < 2*pi*Rload/Lload, piece-a-cake.
>>>
>>> A definitive statement of the problem will produce definitive answers,
>>> otherwise blather and bloviations >:-}
>>>
>>> ...Jim Thompson
>[snip]
>>
>>So, let us start with the LP corner < 2.0*PI*RLoad*Lload,
>>
>>What would be the solution ?
>
>I'll post later today. Hope I got that right for frequency... bit
>foggy-brained after the surgery... it's _lower_ than the natural
>corner of Rload and LLoad ;-)
>
> ...Jim Thompson
My website is down for maintenance, so I've tried dropbox:
<https://www.dropbox.com/s/jmwp76qi8chyvs5/DakupotoMatching.zip?dl=0>
Hope that works!
Let me ponder... there might be an easy way to export a netlist from
LTspice into NGspice.
If not, I believe I've seen original flavor PSpice Schematics
available without the PSpice simulator.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Understanding is a fountain of life to one who has it,
But the instruction of fools is folly. Proverbs 16:22
Reply by Jim Thompson●March 17, 20182018-03-17
On Sat, 17 Mar 2018 08:54:00 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:
[snip]
>
>I think the answer is trivial, but if you refuse to show a sketch, I
>refuse to talk about it.
Larkin's "gentleman/scholar" attitude speaks for itself.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Understanding is a fountain of life to one who has it,
But the instruction of fools is folly. Proverbs 16:22
Reply by Phil Hobbs●March 17, 20182018-03-17
On 03/17/18 02:57, dakupoto@gmail.com wrote:
> On Friday, March 16, 2018 at 10:05:40 PM UTC+5:30, Jim Thompson wrote:
>> On Fri, 16 Mar 2018 04:50:54 -0700 (PDT), dakupoto@gmail.com wrote:
>>
>>> On Friday, March 16, 2018 at 3:42:04 AM UTC+5:30, Jim Thompson wrote:
>> [snip]
>>>>>> Schematic? What does "wideband" mean? fL, fH, dB's?
>>>>>>
>>>>>> ...Jim Thompson
>>>> [snip]
>>>>>
>> [snip]
>>>>>
>>>>> Any hints/suggestions would be very helpful.
>>>>> Thanks in advance.
>>>>
>>>> Gozinta/gozouta specification? You're exhibiting the standard failure
>>>> here of thinking you can force what you think the solution should be
>>>> rather than specifying the desired results... sort like the "Searching
>>>> for an Op-Amp" fiasco >:-}
>>>>
>>>> (I actually have symbols in my spice library: gozinta, gozouta, and
>>>> gozbi... prettied-up _small_ port symbols ;-)
>>>>
>> [snip]
>>
>> NGspice, HSpice noted. LTspice requires all kinds of extra steps to
>> get to a numerically analyzable set of data points
>>
>> Unless HSpice has been recently neutered, I'd hazard a guess that it's
>> .PRINT statement will produce a table in the .OUT file that can pasted
>> into Excel or a curve-fitting program (which is what I mostly use it
>> for... for behavioral modeling ;-)
>>
>>>
>>> I am not forcing anything on anyone. Please read my previous response to your previous message.
>>
>> Then I missed that post... perhaps during my surgery yesterday?
>>
>> I'd like an answer to "What does "wideband" mean? fL, fH, dB's?"
>>
>> If your desired LP corner is > 2*pi*Rload/Lload you've got problems,
>> if < 2*pi*Rload/Lload, piece-a-cake.
>>
>> A definitive statement of the problem will produce definitive answers,
>> otherwise blather and bloviations >:-}
>>
>> ...Jim Thompson
>> --
>> | James E.Thompson | mens |
>> | Analog Innovations | et |
>> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
>> | STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
>> | Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
>> | E-mail Icon at http://www.analog-innovations.com | 1962 |
>>
>> Understanding is a fountain of life to one who has it,
>> But the instruction of fools is folly. Proverbs 16:22
>
> So, let us start with the LP corner < 2.0*PI*RLoad*Lload,
>
> What would be the solution ?
>
There's a tradeoff between the log of the return loss and
bandwidth--it's a theorem of Bode's, so of course it's called the
Fano-Bode limit. See e.g.
http://www.ece.ucsb.edu/~long/ece145a/zmatch.pdf
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttp://hobbs-eo.com
Reply by Jim Thompson●March 17, 20182018-03-17
On Fri, 16 Mar 2018 23:57:38 -0700 (PDT), dakupoto@gmail.com wrote:
>On Friday, March 16, 2018 at 10:05:40 PM UTC+5:30, Jim Thompson wrote:
>> On Fri, 16 Mar 2018 04:50:54 -0700 (PDT), dakupoto@gmail.com wrote:
>>
>> >On Friday, March 16, 2018 at 3:42:04 AM UTC+5:30, Jim Thompson wrote:
>> [snip]
>> >> >> Schematic? What does "wideband" mean? fL, fH, dB's?
>> >> >>
>> >> >> ...Jim Thompson
>> >> [snip]
>> >> >
>> [snip]
>> >> >
>> >> >Any hints/suggestions would be very helpful.
>> >> >Thanks in advance.
>> >>
>> >> Gozinta/gozouta specification? You're exhibiting the standard failure
>> >> here of thinking you can force what you think the solution should be
>> >> rather than specifying the desired results... sort like the "Searching
>> >> for an Op-Amp" fiasco >:-}
>> >>
>> >> (I actually have symbols in my spice library: gozinta, gozouta, and
>> >> gozbi... prettied-up _small_ port symbols ;-)
>> >>
>> [snip]
>>
>> NGspice, HSpice noted. LTspice requires all kinds of extra steps to
>> get to a numerically analyzable set of data points
>>
>> Unless HSpice has been recently neutered, I'd hazard a guess that it's
>> .PRINT statement will produce a table in the .OUT file that can pasted
>> into Excel or a curve-fitting program (which is what I mostly use it
>> for... for behavioral modeling ;-)
>>
>> >
>> >I am not forcing anything on anyone. Please read my previous response to your previous message.
>>
>> Then I missed that post... perhaps during my surgery yesterday?
>>
>> I'd like an answer to "What does "wideband" mean? fL, fH, dB's?"
>>
>> If your desired LP corner is > 2*pi*Rload/Lload you've got problems,
>> if < 2*pi*Rload/Lload, piece-a-cake.
>>
>> A definitive statement of the problem will produce definitive answers,
>> otherwise blather and bloviations >:-}
>>
>> ...Jim Thompson
[snip]
>
>So, let us start with the LP corner < 2.0*PI*RLoad*Lload,
>
>What would be the solution ?
I'll post later today. Hope I got that right for frequency... bit
foggy-brained after the surgery... it's _lower_ than the natural
corner of Rload and LLoad ;-)
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Understanding is a fountain of life to one who has it,
But the instruction of fools is folly. Proverbs 16:22
Reply by John Larkin●March 17, 20182018-03-17
On Sat, 17 Mar 2018 00:09:28 -0700 (PDT), dakupoto@gmail.com wrote:
>On Friday, March 16, 2018 at 8:27:40 PM UTC+5:30, John Larkin wrote:
>> On Fri, 16 Mar 2018 04:12:22 -0700 (PDT), dakupoto@gmail.com wrote:
>>
>> >On Thursday, March 15, 2018 at 9:27:10 PM UTC+5:30, John Larkin wrote:
>> >> On Thu, 15 Mar 2018 05:30:38 -0700 (PDT), dakupoto@gmail.com wrote:
>> >>
>> >> >On Thursday, March 15, 2018 at 5:15:38 AM UTC+5:30, Jim Thompson wrote:
>> >> >> On Tue, 13 Mar 2018 23:39:57 -0700 (PDT), dakupoto@gmail.com wrote:
>> >> >>
>> >> >> >Could some electronics guru please help ? I am running some SPICE
>> >> >> >simulations on wideband impedance matching of the following setup.
>> >> >> >The source and load resistances are equal
>> >> >> >The source is a pure resistor
>> >> >> >Yhe load consists of a resistor(same value as source resistor) and
>> >> >> >a series inductor
>> >> >> >The matching network is a 6th order low pass filter with a
>> >> >> >series inductor as the last element.
>> >> >> >The RMS input power and the RMS output power are measured.
>> >> >> >The ratio RMS output power/RMS input power is very low, indicating
>> >> >> >poor matching and large invident signal reflection. How would the
>> >> >> >load inductor be bullified in a physically realizable way ? All
>> >> >> >hints/suggestions are welcome. Thanks in advance.
>> >> >> >
>> >> >> >
>> >> >>
>> >> >> Schematic? What does "wideband" mean? fL, fH, dB's?
>> >> >>
>> >> >> ...Jim Thompson
>> >> >> --
>> >> >> | James E.Thompson | mens |
>> >> >> | Analog Innovations | et |
>> >> >> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
>> >> >> | STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
>> >> >> | Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
>> >> >> | E-mail Icon at http://www.analog-innovations.com | 1962 |
>> >> >>
>> >> >> It's what you learn, after you know it all, that counts.
>> >> >
>> >> >The SPICE netlist is listed below:
>> >> >Low pass filter impedance matching
>> >> >* Identical load source resistance
>> >> >* and series load inductor
>> >> >
>> >> >.PARAMS FREQ=3.453144e+08 LLIM=1.726572e+07 HLIM=6.043003e+08 AMPL=10
>> >> >
>> >> >.SUBCKT LPFILT 1 2
>> >> >* 1 IN
>> >> >* 2 OUT
>> >> >C1 1 0 2.353875e-10
>> >> >L2 1 3 6.431530e-10
>> >> >C3 3 0 8.787569e-10
>> >> >L4 3 4 8.791318e-10
>> >> >C5 4 0 6.441774e-10
>> >> >L6 4 2 2.367870e-10
>> >> >.ENDS
>> >> >
>> >> >* COMMENT OUT TRANSIENT ANALYSIS
>> >> >* TO RUN AC ANALYSIS AND VICE-VERSA
>> >> >
>> >> >LLOAD 6 7 1.200000e-08
>> >> >LCOMP 5 6 1.772026e-11
>> >> >RSRC 1 2 50.000000
>> >> >RLOAD 7 0 50.000000
>> >> >XLP 3 4 LPFILT
>> >> >VTST0 2 3 DC 0.0 AC 0.0
>> >> >VTST1 4 5 DC 0.0 AC 0.0
>> >> >
>> >> >* FOR TRANSIENT ANALYSIS
>> >> >VSIG 1 0 DC 0.005 SIN(0 {AMPL} {FREQ} 0 0 0)
>> >> >* FOR AC(SMALL SIGNAL) ANALYSIS
>> >> >VSIG 1 0 DC 0.005 AC {AMPL})
>> >> >
>> >> >.OPTIONS METHOD=GEAR NOPAGE RELTOL=1m MINBREAK=5ps
>> >> >.IC
>> >> >.TRAN 75.0ns 500.0us 50.0ns UIC
>> >> >* INPUT/SOURCE SIDE
>> >> >.PRINT TRAN V(3) I(VTST0)
>> >> >* LOAD/OUTPUT SIDE
>> >> >.PRINT TRAN V(4) I(VTST1)
>> >> >
>> >> >.AC LIN 20000 {LLIM} {HLIM}
>> >> >.PRINT AC V(5)
>> >> >** FOR REFLECTION COEFFICIENT ETC.,
>> >> >.PRINT AC V(2)
>> >> >.END
>> >> >
>> >> >Any hints/suggestions would be very helpful.
>> >> >Thanks in advance.
>> >>
>> >> Can you post a visible schematic?
>> >>
>> >> I still don't know what you are trying to do.
>> >>
>> >> I've done some work lately on one-end-reflectionless lowpass filters,
>> >> based on Jeroen's concepts. Mini-Circuits has some interesting new
>> >> symmetric filters, both-ends-reflectionless.
>> >>
>> >>
>> >> --
>> >>
>> >> John Larkin Highland Technology, Inc
>> >>
>> >> lunatic fringe electronics
>> >
>> >I am afraid I do not have a visible schematic. I use HSpice at work, and Ngspice at home, both of which use the text input. It is sometimes bothersome to enter a new large netlist, but
>> >editing is very easy.
>>
>> Just a sketch would help. I don't know what you are trying to do.
>>
>> LT Spice lets you draw a schematic instantly. Typing (and reading!)
>> netlists is really old-fashioned.
>>
>>
>>
>>
>> --
>>
>> John Larkin Highland Technology, Inc
>>
>> lunatic fringe electronics
>
>The setup is simple :
>A signal source feeds a low pass ladder matching network, e.g., of order 6. The source impedance is purely resistive (NO source reactance). The load is a resistor in series with an inductor. The load and source resistors have the same value
>So how do I compensate for the frequency dependent load inductor ?
I think the answer is trivial, but if you refuse to show a sketch, I
refuse to talk about it.
--
John Larkin Highland Technology, Inc
lunatic fringe electronics
Reply by Tim Williams●March 17, 20182018-03-17
<dakupoto@gmail.com> wrote in message
news:cebd7825-b7be-4dd0-9442-0a22f5a5d686@googlegroups.com...
> I am afraid your suggested solution is very vague. Suppose the load
> inductor is 1 microHenry.
> Inverting this, the corresponding capacitor
> would have a value if 1 Mega Farad -- not physically realizable. Are you
> talking in terms of reactance in Ohms ? If so, what would be the
> frequency ?
Filters are designed at unity frequency. I can't write lowercase omega, so
I said w=1 which looks similar. Use the same transformations as from any
filter table to get Zo and Fo.
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: https://www.seventransistorlabs.com/