Topics

errors of "error" models

 

40 : The [LeastVNA] - Update 3

Hello,

We are terribly sorry for the inconvenience, but allow us,
please, to inform you that we just revised and withdrawn
the previous description of [LeastVNA] given at:

39 : : The [LeastVNA] - Update 2 - 9 October 2019 :
https://groups.io/g/nanovna-users/message/4456

and then:

(I) we amplified the paragraph (5) at its following point:

- instead of the weak:

"where these special places are always "far" away, but
equidistantly, from the connector"

- we put the strong:

"where these special places are always "far" away,
but at the ends of two paths which are exactly the same,
in every aspect, from the connector"

as well as:

(II) we clarified more the paragraph (8) by slightly
modified it,

so that, the new, updated description of [LeastVNA]
has now as follows:

- - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - -

- From A Common User's Point Of View -

An operating [LeastVNA] system:

(1) Includes an internal or external device with at least one
external connector, where the User connects a load

(2) Has an internal or external cosinusoidal voltage generator
working within an operating range of frequencies, briefly:
"source", that produces a cosinusoidal voltage oscillation with
frequency f, briefly: "signal", as its output towards to load

(3) Produces, unavoidably, with its source, two cosinusoidal
voltage waves in f, coexisting at least into the connector, as
well as "far" beyond that, "elsewhere" internally, which are
directed, with respect to the connector, as Input and Output
waves, briefly: "waves", and named as the Reflected wave
from the load and the Incident wave to the load, respectively

(4) These coexisting waves manifest themselves locally in
various places of their paths as two locally coexisting signals,
resulting from these waves and identified by the amplitude
and phase of these two coexisting waves, respectively

(5) Separates, somewhere internally, these two coexisting waves
and delivers to itself, at two special places internally, two
separated signals r and i, identified by the amplitude and phase
of these two separated waves at these special places,
respectively, where these special places are always "far" away,
but at the ends of two paths that are exactly the same, in every
aspect, from the connector, having amplitudes and
phases ( ar , pr ) and ( ai , pi ), respectively

(6) Forms and measures a couple of values for the following
two dimensionless quantities:

( amplitude ratio a, phase difference p ) ,

from these two separated signals r and i, as follows:

( a = ar/ai , p = pr - pi )

(7) Presents these two values a and p to the User as indications
or readings, with a finite number of digits of course, which are
obviously resulting from the presence of the connected load

Finally, after all that said:

(8) The User should expect that, in general, these two
indications a and p of the internally separated signals r and i
-
once again : at special places "far" away from the connected
load
-
may be quite different from the values A and P, which the User
should except that they exist between the coexisting signals
R and I on the connector, resulting and identified respectively
from the coexisting waves there, that is from the load connected
there, which is finally the sole responsible of their appearance
during the [LeastVNA] operation
-
the User has been warned

- - - end : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - -

Please, accept our apologies.

Sincerely,

gin&pez@arg

PS
Next to come :
The "error" models facupov - that is in terms of [LeastVNA]

40

Gary O'Neil
 

Hello gin&pez@arg;

I interpret variables r and i as reflected and incident respectively in this context. Is this interpretation correct?

In paragraph 8 please clarify the difference between "a and p" with respect to "A and P".

Also please clarify in paragraph 8: The user should "except" is confusing in this context.

".... which the User
should except that they exist between the coexisting signals
R and I on the connector,..."

Do you mean "The user should expect that they exist..."?


--
73

Gary, N3GO

 

41 : Corrections and Confirmations to
40 : [LeastVNA] - Update 3 - 9 October 2019 :
https://groups.io/g/nanovna-users/message/4461

@Gary O'Neil - 9 October 2019:
https://groups.io/g/nanovna-users/message/4483

Hello Gary,

And thank you very much for your kind attention !

Yes, indeed, your are right to correct our anagram
in the wrong "except" to the correct "expect".

Yes indeed, ( a , p ) symbolizes the couple of the
values indicated to the User, as they are resulted
"far" away from the connector, on which their
values are imposed by the load and thus they are
symbolized there as the ( A , P ) couple or in order
to undoubtedly present the used symbolization:

( a , p ) | on the connector := ( A , P ) | of the load

because it is the load that has been fixed on the
connector.

Yes, indeed, in this Update 3 of our description of
[LeastVNA] the letters "r" and "i", being the initial
letters of the words "reflected" and "incident", are
used as the symbols of the signals resulted in
various places on the paths of the either coexisting
or separated reflected and incident waves,
respectively, and so they are still used in the two
special places where [LeastVNA] forms the couple
of dimensionless quantities having the ( a , p )
values.

Well, after all that, which are in addition to those, yet
unpublished, weaknesses we already noticed, it seems
that at least another one Update of our [LeastVNA]
description is unavoidable...

Anyway, we have to apologize to you regarding our
long delay of our still postponed by us replies to
your other, most valuable, comments. Our excuses
have to do with our heavy work that is reflected,
as we hope, to our messages.

Please, accept our apologies - Please, stay tuned.

Kind regards,

73

gin&pez@arg

41

 

#42 : The compact SLO formula for [AnyVNA]

Hello,

Allow us, please, to inform you that our two final reports:

1 : #30 : 5 October 2019 : https://groups.io/g/nanovna-users/message/4179
https://www.op4.eu/code/ref2007box/r.ref2007box.blue.vna.red.nanovna.c.gza.cc.by.4.0.png
https://www.op4.eu/code/ref2007box/x.ref2007box.blue.vna.red.nanovna.c.gza.cc.by.4.0.png

2 : #38 : https://groups.io/g/nanovna-users/message/4293
https://www.op4.eu/code/ref2007box/r.box.nanovna.deis.c.gza.cc.by.4.0.png
https://www.op4.eu/code/ref2007box/x.box.nanovna.deis.c.gza.cc.by.4.0.png

are resulted after we used the formulas given at:

#16 : 27 September 2019 : https://groups.io/g/nanovna-users/message/3161
https://www.op4.eu/code/cc-by-4.0-gz-ain-vna-params.png

with the clarifications provided at:
#17 : 27 September 2019 : https://groups.io/g/nanovna-users/message/3192

for the following Nominal Values of SLO "standards":

Short : A := S = Polar : ( 1 , 180 ) = Cartesian : ( -1 , 0 ) = Complex : -1 + j0 = Real : -1
Load : B : = L = Polar : ( 0, undefined) = Cartesian : ( 0, 0 ) = Complex : 0 + j0 = Real : 0
Open : C := O : Polar : (1 , 0) = Cartesian : ( 1 , 0) = Complex : 1 + j0 = Real : +1

and the following Indicated values of our [NanoVNA]
and [VNA]

Short Indication : a := s
Load Indication : b := l
Open Indication : c := o
Unknown load Indication : gamma

substituted to:
https://www.op4.eu/code/cc-by-4.0-gz-ain-vna-params.png

to got the following minimal mathematical expression
for the Unknown Gamma measured by [AnyVNA] - all complex:

https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png

at each defined frequency.

Sincerely,

gin&pez@arg

#42

 

#43 : On the Phase

@Gary O'Neil : Sun, Oct 6, 2019 at 04:45 PM
https://groups.io/g/nanovna-users/message/4194

Dear Gary,

We thank you very much, indeed, for this particular
comment:

"More precisely, any VNA measures amplitude vs.
frequency, and either measures or computes phase",

because -by one of the many positive side effects it
still has- it forced us to insist -as a challenge,
as usual : that is without resorting to any reference-
so that to finally remember -some minutes before-
that way -so simple, but forgotten- by which anyone
can expresses the Phase proving that the superposition
of two cosinusoidal waves of the same frequency is
indeed a cosinusoidal wave of the same frequency.

Therefore, once more : Please stay tuned !

Best regards,

73

nikolitsa oe3zgn|sv7dmc & petros oe3zzp|sv7bax @ arg iaoi nfi

43#

 

#44 : Answers

@Gary O'Neil - Sun, Oct 6, 2019 at 05:28 AM:
https://groups.io/g/nanovna-users/message/4169

- also any other interested reader and/or contributor -

Dear Gary,

Once again : We are terribly sorry for this delayed
reply. However, our excuses remain constantly the
same : hard work. Please, accept our apologies.

Anyway, as we promised, here are our answers to your
specific questions:

1
The [ANALYSE] Tool (Documentation : PDF 2/15) is an
application software that we developed in order to control
through HP-IB and synchronize the overall operation of
the following five 5 different instruments:

(1) An HP8505A VNA

(2) An HP8660C Synthesized Signal Generator for PLL

(3) An HP5340A Frequency Counter in order to achieve
100 Hz frequency accuracy

(4) A step-motor, extracted from a big printer, as well as
a motor controller, which we built to be used for antenna
radiation/pattern measurements, and

(5) the computer we used to collect the indications of both
magnitude/amplitude/modulo or what other name and the
phase/argument can be used for all of them.

Thus, it was indeed a software tool designed and developed
for our automatic VNA measurement system and it is of course
independent of the rest of our work for our definition of DERs
and DEIs, as well as their determination.

Nowadays we see that VNAs use different ways to communicate
with the user and to give their data. For example we took the
[NanoVNA] data with the [Putty] via the USB interface.

This is all the reasons of why we do not describe in details this tool.

2
The 4 files [SH.SC], [OP,OC], [LD.LD], and [ME.ME] are the four
4 needed measurements in 101 frequencies, from 600 to 1000 MHz,
with a 4 MHZ step, for a ground plane antenna, as we have already
mentioned. The first three 3 are for the calibration with the "known"
SLO "standards" and the last one is the measured indications of the
antenna. All these text files have the same simple format:

frequency [MHz] - magnitude [dB] - argument [degrees]

The number of digits used are what we have from our measurement
system. And since these files are text files we can easily change their
format.

And we indeed changed recently the frequency format, since the
frequency counter we have now available can not give us -at least for
the moment- the 100 Hz accuracy we had 10 years ago - only 10 KHz.

Note: All the measurements in all of our presentations in ANAMET
- Automatic Network Analzer Metrology Club of NPL - or in our papers
were taken in CW mode, while we haven't used yet our [NanoVNA]
in CW mode.

3
The so-called system "errors" (D,M,R) or (Ed, Es, Er)
or (D,S,R) or whatever else other name, are just intermediate
complex variables and that is why we do not included an
output file for them. But we could add one easily, of course,
if there is such a need.

4
The well-known full one-port "error" model was adopted,
and the well-known relation of the bilinear transformation
was used * w i t h o u t * any simplification or term
elimination. All the involved quantities are in the complex
plane.

5
The method of determining an uncertainty estimation
in the reflection coefficient of the full one-port DUT, or of
any other quantity or "quantity" that is dependent on the
reflection coefficient such as e.g. the input impedance,
is based on the usual total differential laws as we applied
them in this specific case of complex functions of many
complex variables.

6
As we already mentioned elsewhere in our messages to
the group:

In order to keep the relations general the capital letters
A,B,C was used for the three "standard" loads for the
calibration and the three small letters a,b,c for their
corresponding measurement indications. Thus for a SLO
calibration we have - once again:

A = S = -1 (magnitude 1, argument 180 degrees),

B = L = 0 (magnitude 0, argument undetermined), and

C = O = 1 (magnitude 1, argument 0 degrees).

For their uncertainty we have - once again :

S : -0.01 for magnitude, +/-2 degrees for argument,

O : -0.01 for magnitude, +/-2 degrees for argument, and

L : 0.029 for magnitude, none for the undetermined argument

For the measurement inaccuracies, we used for all the four
4 measurements s, l, o, m:

+/-1 digit of the LSD for both magnitude and argument
readings or indications.

Thus, the uncertainties of the "standard" loads and the
inaccuracies of the measurements are all in the complex plane.

7
The final estimated uncertainty for reflection coefficient
of the DUT is the Differential Error Region DER in the
complex plane for each frequency with the corresponding
Differential Error Intervals DEIs for real and imaginary parts
in the Cartesian form, as well as and the DEIs for the
magnitude and argument in the Polar form.

Maxima was used basically for that presentation in ANAMET
and especially for the DERs, since for the DEIs any program
that plot points and lines can be used. But the plotting of a
DER needs a special treatment in order to correctly combine
rather many straight lines and circular arcs and thus it is
more tedious to be drawn.

Details for the DERs and DEIs are given in our papers and
thhree ANAMET presentations.

Please, stay tuned !

Best regards,

73

nikolitsa oe3zgn|sv7dmc & petros oe3zzp|sv7bax @ arg iaoi nfi

44#

 

#45 : errors instead of "errors" : [NanoVNA] Indications for
"standard" Nominal Values

Hello,

Allow us, please, to demonstrate the big difference between
Indications and Nominal Values for [AnyVNA], using our
[NanoVNA] and our "standard" load [ref2007box], measured
by our [VNA] and thus having the BLUE Nominal Values against
the RED Indications, taken with our [Nanovna], in the following
two figures - in terms of frequency:

"Amplitude" of Rho (in "non-dB" pure numbers) :
https://www.op4.eu/code/ref2007box/a.red.A.BLUE.c.gza.cc.by.4.0.png

"Phase" of Rho (in degrees) :
http://op4.eu/code/ref2007box/p.red.P.BLUE.c.gza.cc.by.4.0.png

After that, allow us, please, to rhetorically ask :

"Is there an observer who would like to not call "errors", but just
errors without quotes, these really big differences ?"

Sincerely,

gin&pez&arg

45#

Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
 

Would “uncertainty of errors correction terms” not be a better title?

On Mon, 14 Oct 2019 at 15:24, yza <yzaVNA@...> wrote:

#45 : errors instead of "errors" : [NanoVNA] Indications for
"standard" Nominal Values

Hello,

Allow us, please, to demonstrate the big difference between
Indications and Nominal Values for [AnyVNA], using our
[NanoVNA] and our "standard" load [ref2007box], measured
by our [VNA] and thus having the BLUE Nominal Values against
the RED Indications, taken with our [Nanovna], in the following
two figures - in terms of frequency:

"Amplitude" of Rho (in "non-dB" pure numbers) :
https://www.op4.eu/code/ref2007box/a.red.A.BLUE.c.gza.cc.by.4.0.png

"Phase" of Rho (in degrees) :
http://op4.eu/code/ref2007box/p.red.P.BLUE.c.gza.cc.by.4.0.png

After that, allow us, please, to rhetorically ask :

"Is there an observer who would like to not call "errors", but just
errors without quotes, these really big differences ?"

Sincerely,

gin&pez&arg

45#



--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

 

#46 : Comment

@Dr. David Kirkby from Kirkby Microwave Ltd - 14 October 2019
https://groups.io/g/nanovna-users/message/4890

Hello,

Thank you for your suggestion.

However, in our humble opinion, putting the name into quotes
is adequately enough to clarify the concept without disturbing
the connection with the well-known calibration technique having
it in its title.

Sincerely,

gin&pez@arg

46#

Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
 

On Mon, 14 Oct 2019 at 19:44, yza <yzaVNA@...> wrote:

#46 : Comment

@Dr. David Kirkby from Kirkby Microwave Ltd - 14 October 2019
https://groups.io/g/nanovna-users/message/4890

Hello,

Thank you for your suggestion.

However, in our humble opinion, putting the name into quotes
is adequately enough to clarify the concept without disturbing
the connection with the well-known calibration technique having
it in its title.

Sincerely,

gin&pez@arg

I am *not* a metrologist, but I find this document useful

“A Beginner’s Guide to Uncertainty of Measurement”. It is written by a lady
at the National Physical Laboratory (NPL) in the UK.

https://www.npl.co.uk/special-pages/guides/gpg11_uncertainty

I realise that you are metrologists, but with English not being your
first language, maybe you use different terms to us.

I will quote a little from that document:

“ *2.3 Error versus uncertainty*
It is important not to confuse the terms ‘error’ and ‘uncertainty’.

*Error* is the difference between the measured value and the ‘true value’
of the thing being measured.

*Uncertainty* is a quantification of the doubt about the measurement result”

At far as I am aware, you don’t know the true value of anything relevant to
the VNA. Since you don’t know the true value of anything, you can not
calculate an error.

I realise that the term “error correction” is used in by engineers using
VNAs, so I am not suggesting that you remove the word word error. But I
would suggest that you should probably be using the word “uncertainty” in
your title.

I am not following the work you are doing, so don’t know exactly what you
are doing. But I suspect that the word uncertainty should be in the title
of your document, but maybe I am mistaken.

Dave




--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

 

#47 : Once Again

@Dr. David Kirkby from Kirkby Microwave Ltd - 14 October 2019 :
https://groups.io/g/nanovna-users/message/4907

Hello,

After your suggestion, allow us, please, to also suggest to you,
once again, after the previous one with our message:

25 : The concept of Quantity today - 1 October 2019 :
https://groups.io/g/nanovna-users/message/3106

to read -but now specifically- just the last proposition, of the third
paragraph from below, in page viii, of the Introduction to "VIM3", at:

[JCGM_200_2012.pdf]

packed in:

https://www.bipm.org/utils/common/documents/jcgm/JCGM_pack_2012-10.zip

and after that, to please you, once more, to not bother yourself
anymore with a possibly loose terminology but to concentrate in
the essence of:

"how much is the uncertainty (or deviation or whatever other
name may it has) of the [AnyVNA] measurement results,
if someone -according to his taste, of course- wants to estimate it
by taking into account the given uncertainties of the -unquoted-
standards, as well as the inaccuracies of the readings"

that is on a matter with unknown answer until about 10 years
before.

Because, as you see, this has nothing to do with "translation problems"
or "language barriers" or whatever else may someone thinks that it is
the responsible of his "non-understanding", as we also already pointed
in our message:

#13 : @erik@... - 26 September 2019 :
https://groups.io/g/nanovna-users/message/3106

from which allow us, please, to repeat here the following excerpt:

| Finally, allow us, please, to comment that, in our humble
| opinion, regarding 'Understanding', there are the following
| types of human beings, according their personal tastes:
|
| (1) Those who don't want to understand, and those who want
| to understand, but when they don't understand then, according
| to their judging abilities, they put constantly the blame:
|
| (2) on the others,
|
| (3) on themselves, and
|
| (4) either on the others or on themselves, according to the state
| of their progress in the Knowledge

Sincerely,

gin&pez@arg

47#

 

#48 : ann : update 3 of [LeastVNA] is withdrawn

Hello,

After the comments made by Gary O'Neil on
9 October 2019:

https://groups.io/g/nanovna-users/message/4483

which resulted to our:

41 : Corrections and Confirmations to
40 : [LeastVNA] - Update 3 - 9 October 2019
https://groups.io/g/nanovna-users/message/4519
Thu, Oct 10, 2019 at 11:59 AM :

where we specifically admitted that:

| Well, after all that, which are in addition to those, yet
| unpublished, weaknesses we already noticed, it seems
| that at least another one Update of our [LeastVNA]
| description is unavoidable...

we found that we have to make major changes
to our [LeastVNA] and thus to upgrade it as a
whole, so we withdraw its update 3, as well as
* a n y * other previous edition of it.

Sincerely,

gin&pez@arg

48#

 

#49 :
first details of our final report 1 :
nominal values comparison :
our [NanoVNA] ~ our [VNA]
-
#30 : our final report 1 - 6 October 2019 :
https://groups.io/g/nanovna-users/message/4179
-

Hello,

Allow us, please, to present the first details of our
final report 1 regarding the Nominal Values of Rho
for our [ref2007box], as they resulted by using
our [VNA] and our [VNA]:

Rho Magnitude:
[VNA] : CYAN - pre-calibrated
[VNA] : BLUE - Nominal Values
[NanoVNA] : MAGENTA - pre-calibrated
[NanoVNA] : RED - Nominal Values:
https://www.op4.eu/code/ref2007box/ref2007box_VNA.NanoVNA_Mag_box=CYA.BOX=BLU.box=MAG.BOX=RED.c.gsa.cc.by.4.2019.png

Rho Argument:
[VNA] : CYAN - pre-calibrated
[VNA] : BLUE - Nominal Values
[NanoVNA] : MAGENTA - pre-calibrated
[NanoVNA] : RED - Nominal Values:
https://www.op4.eu/code/ref2007box/ref2007box_VNA.NanoVNA_Arg_box=CYA.BOX=BLU.box=MAG.BOX=RED.c.gza.cc.by.4.2019.png

Sincerely,

gin&pez@arg

49#

Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
 

On Mon, 14 Oct 2019 at 23:53, yza <yzaVNA@...> wrote:

#47 : Once Again

@Dr. David Kirkby from Kirkby Microwave Ltd - 14 October 2019 :
https://groups.io/g/nanovna-users/message/4907

Hello,

Hello,


After your suggestion, allow us, please, to also suggest to you,
once again, after the previous one with our message:

25 : The concept of Quantity today - 1 October 2019 :
https://groups.io/g/nanovna-users/message/3106

I am sorry, but you keep giving links rather than comment is very tiresome
for me.

| Finally, allow us, please, to comment that, in our humble
| opinion, regarding 'Understanding', there are the following
| types of human beings, according their personal tastes:
|
| (1) Those who don't want to understand, and those who want
| to understand, but when they don't understand then, according
| to their judging abilities, they put constantly the blame:
|
| (2) on the others,
|
| (3) on themselves, and
|
| (4) either on the others or on themselves, according to the state
| of their progress in the Knowledge

Sincerely,

gin&pez@arg

Your comments such as those above about the abilities and attitudes of
different people is seen as rude by myself.

Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

 

#50 : The Full Final Report 1 :
- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Nominal Values Zinp = ( Rinp , Xinp )
of our Standard [ref2007box], in terms of
frequency, using [NanoVNA] and [VNA]
- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
[NanoVNA] ~ [VNA] Comparison

#30 : our final report 1 - 6 October 2019 :
https://groups.io/g/nanovna-users/message/4179

- also @Gary O'Neil - 8 October 2019 -
https://groups.io/g/nanovna-users/message/4385


Hello,

Allow us, please, to present the steps by which we got the
results of our final report 1.

- - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - -

First of all, in order to set up a Somehow Reliable Comparison
between our [NanoVNA] and our [VNA], we decided to put aside
the sma/M SLO "Standards" and use our TypeN/M 50 Ohm SLO
'Standards', as well as our Standard [ref2007box], to both our
[NanoVNA] and [VNA]. So, to get the Same Reference Plane
for both instruments, we used our [sma/M-to-typeN/F 50 Ohm]
adapter directly connected to [CH0] port of [NanoVNA].

After that, since we already had our [VNA] results under these
very same SLO+[ref2007box] conditions, we used only Putty to
collect the measurements from [NanoVNA] and proceed step-by-step
to the following graphics:

I/III
The four 4 measurements : ( s, l, o, gamma ) needed
for our expression of Gamma:

#42 : The compact SLO formula for [AnyVNA]:
https://groups.io/g/nanovna-users/message/4747
12 October 2019

by using our [NanoVNA] : RED points in the following Figures,
as well as by our [VNA] : BLUE points in the same Figures :

I.1/4 : SHORT CIRCUIT Measurements : s
Magnitude : https://www.op4.eu/code/ref2007box/rN-Vb_SHO_sm_c.gsa.cc.by.4.2019.png
Argument : https://www.op4.eu/code/ref2007box/rN-Vb_SHO_sa_c.gsa.cc.by.4.2019.png

I.2/4 : (MATCHING) LOAD Measurements : l
Magnitude : https://www.op4.eu/code/ref2007box/rN-Vb_L05_la_c.gsa.cc.by.4.2019.png
Argument : https://www.op4.eu/code/ref2007box/rN-Vb_L05_lm_c.gsa.cc.by.4.2019.png

I.3/4 : OPEN CIRCUIT Measurements : o
Magnitude: https://www.op4.eu/code/ref2007box/rN-Vb_OOA_om_c.gsa.cc.by.4.2019.png
Argument : https://www.op4.eu/code/ref2007box/rN-Vb_OOA_oa_c.gsa.cc.by.4.2019.png

I.4/4 : Our Standard [ref2007box] : gamma
Magnitude: https://www.op4.eu/code/ref2007box/rN-Vb_R07_gm_c.gsa.cc.by.4.2019.png
Argument : https://www.op4.eu/code/ref2007box/rN-Vb_R07_ga_c.gsa.cc.by.4.2019.png

II/III
The Nominal Value Gamma of Our Standard [ref2007box]:

By substitution of the above measurements - from I.1/4 to I.4/4 -
to our expression:

https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png

we got for the Nominal Value Gamma of Our Standard [ref2007box],
in terms of frequency, once more:

RED points in the following Figures by using our [NanoVNA],
BLUE points in the same Figures, by using our [VNA]:

Magnitude : https://www.op4.eu/code/ref2007box/rN-Vb_R07_Gm_c.gsa.cc.by.4.2019.png
Argument : https://www.op4.eu/code/ref2007box/rN-Vb_R07_Ga_c.gsa.cc.by.4.2019.png

III
The Nominal Values of Zinp for Our Standard [ref2007box]:

By using the well-known formula :

Zinp = Zo*(1+Gamma)/(1-Gamma)

where Zinp and Gamma are, in general, Complex variables
and Zo is the Real Nominal Value = 50 Ohm

we got the two Parts of Zinp, as follows:

Real Part : https://www.op4.eu/code/ref2007box/r.ref2007box.blue.vna.red.nanovna.c.gza.cc.by.4.0.png
Imaginary Part : https://www.op4.eu/code/ref2007box/x.ref2007box.blue.vna.red.nanovna.c.gza.cc.by.4.0.png

#30 : our final report 1 - 6 October 2019 :
https://groups.io/g/nanovna-users/message/4179

- - - end : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - -

Sincerely,

gin&pez@arg

50#

 

#51: the full final report 1 with contiguous full online images is here:

https://acomelectronics.com/forum/viewtopic.php?p=1311#p1311

51#

Gary O'Neil
 

Hello again GIN & PEZ;

Your #51 full final report is a much improved compilation but as mentioned earlier, it is quite difficult to read and follow, much less comprehend, when it requires navigating through numerous links. This report answers some of my questions, and is helpful toward identifying questions that remain for this to be understood. Some of my questions may fall out as I digest this more; based on inferences borne out of my current sense of understanding. As such; I will summarize and then start with some of the more obvious questions needed to fill in some details as I digest more of what you have presented.

I believe you presented, in one of your earlier "final" posts, the raw data files used to generate the plots in your "full final". I was frustrated by not having a means to perceive or evaluate that data in my journey toward understanding what is being presented. To that end; I attempted to download and install the software you identified in an earlier post on this topic as an effort to replicate your results. This appeared to be the only means you were providing as a vehicle to our understanding. My attempt at this was abruptly terminated upon my discovery that the link you provided to your Fortran complier openwatcom-fortran][1.9] went dark a few years ago, and further research turned up on shadowed versions.

It should be obvious why this is a major issue, but I will explain why it is for me in order that you understand the magnitude of the handicap it presents and the disconnect we have with respect your intentions of presenting your project FACUPOV.

1) Fortran is a powerful programming language, and much high quality legacy code requires it (the compiler) to be supported to ensure that the legacy programs can be maintained and remain relevant. Your source dictates this.
2) Fortran comes in many forms, versions, etc., including the compiler you use or have been using. It must be made available in order to ensure that your source code compiles accurately as you intend it to compile.
3) Fortran source code is quite readable by most skilled programmers who, out of necessity, have become multi-lingual coders as a consequence of making programming their career. A few appear to be on this list.
4) Using any compiler to create an executable product from a source not written for it, as its native compiler and version, is likely going to yield errors. Some errors may be minor and easily corrected; some may require new code and/or structure changes; any and all of which will likely require a seasoned programmer. I may be a bit off of the mark on the following; but I don't believe Fortran is likely the language of choice taught to freshmen programmers recently.
5) FACUPOV; most seasoned RF designers, and many RF technicians are familiar with, and can hack at code in various programming languages; and their skill level may vary from novice to advanced. This may be a Common User asset, but their POV may be vastly different. Any derivative of your work will take on as many different forms as there are attempts made to get it up and running. You might even cringe at some of their craftsmanship, because their interpretation of your work doesn't quite pass muster.
6) Either attempting to work through the above while holding fast to the notion that the tasks will yield legitimate results, or writing independent software to manipulate and exercise your equations in a manner consistent with our very limited understanding thusfar, are both significant tasks, either of which are prone to misinterpretation, miscalculation, and false conclusions about what you wish for us to understand, and I trust you would agree that doing so if far beyond the expectations of being FACUPOV.

If I may suggest and recommend a relatively straight forward solution that may advance your progress, whether or not you are successful toward reaching your goal here.

I believe your requirements here can be fulfilled by the ambition and skill set of an undergrad, or freshman graduate studant.

As I described earlier; I think the entire process you describe in your final report can be coded into a single executable which then could be distributed to clients of interest to you. If I am incorrect in this assessment; it must be concluded that I remain far away from understanding your project. If your passion about your work that comes through in your writings is being correctly interpreted, then I would expect that you would concur such a task is both worthwhile and warranted.

You would first have to mentor the student on how each of the component modules interact, from data input to graphical output. Allow them to pursue the task of learning the Touchstone format as the desired format for the input data of the executable. This will greatly mobilize your ability to gather data from competing sources as test cases.

If you wish to maintain your automated data collection system as your own and ongoing source of input to the executable, the student could also be tasked to write a separate format conversion module in Fortran to ease the task of reducing the data it provides into a format compatable with the more universal Touchstone format used as input to the executable program.

It may be of further benefit to give the student the freedom of choice for the programming language used with the caveat that it needs to yield both a Windows and Linux version.

-
73

Gary, N3GO

Gary O'Neil
 

Hello again GIN & PEZ

I wish to have some clarification that I am interpreting the test configuration correctly.

What were the Putty commands you used to extract data from the NanoVNA? Can you confirm the data as raw (uncorrected) or post calibration corrected measurements?

Your VNA data (blue) appears to have been taken at a significant offset from the reference plane. If this is uncorrected raw data it makes sense in an automated VNA environment.

It is also my expectation that you used raw data from both VNA's when producing your full final report 1 results.

I am interpreting your full final report 1 as follows:

1. The measurement data given and shown plotted is the independent raw magnitude and phase data collected for each of your set of fully characterized S. L, and O standards on your (Blue) VNA, and the (Red) NanoVNA.
2. The fourth is also measurement data, but it is the raw magnitude and phase data for your fabricated example DUT identified as " Our Standard [ref2007box]" and labeled as gamma. This is the raw measured data of the DUT, and not corrected or modified in any manner to yield a gamma value.
3.The data to this point are inputs to the nominal gamma equation and concludes part 1 of 3 parts (I / III)
4.Part 2 of 3 exercises the equation shown: https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png to yield the corrected value for the DUT with respect to the implied (absolute) accuracy of the characterized SOL standards employed without regard to measurement uncertainties... including any uncertainties embedded within the bounds of the characterized calibration standards employed.
- - - For clarification please:
The variables used in the gamma equation shown are assumed to be the complex values of the measurements as displayed graphically as magnitude and phase pairs.
There are no numerical values or constants in the equation... i.e. the o is symbolic of the open measurement values, the 1 is symbolic of the load standard measurement values, and the lower case gamma is symbolic of the DUT measurement values, etc.
There are no calibration correction coefficients used in producing any of this data, nor in any of the computed results plotted in this report. To that point, the calibration standards used are considered ideal and perfect.
The upper case gamma is the computed complex result of this equation representing the corrected measured value of the DUT, and is interpreted as the reflection coefficient of the DUT at the measurement frequency.
The result of these computations performed at each of the measurement frequencies is then plotted as the corrected "nominal" reflection coefficient of the DUT for both magnitude and phase. This then enables one to graphically visualize the nominal result differences between VNA performance under exactly identical measurement conditions, independent of the standards and DUT used for the comparison, and completes part 2 of 3 (II / III).

The inference that one can observe at this point is that the two VNA's being evaluated differ in performance and/or measurement accuracy. If performance and accuracy were identical, one would expect the blue and red data points to overlay precisely. Evident here is that the two VNA's in fact disagree within yet to be defined uncertainty boundaries, revealing the fact that this full final report 1 will be followed by a full final report 2.

The NanoVNA is clearly shown, not surprisingly, to be inferior in performance. It doesn't disclose any explanation for the differences shown, but those skilled in the art could quickly and easily identify a number of contributors, as well as quantify the consequence of the performance tradeoffs that the differences imply. The assumption here of course is that trace smoothness versus frequency equates to goodness in performance, but is not an unreasonable assumption..

As to whether or not the nominal measurement differences are a compromising concern is perhaps the intent your work; which I anticipate to next be presented in the context of a mapping of the uncertainty boundaries surrounding this pair of nominal VNA measurement exercises.

Part 3 of 3 (III / III) is simply the computed complex impedance derived algebraically from the the equation for expressing reflection coefficient in complex impedance form.

This is all quite encouraging. I believe that I am now following your process up to this point. If any of my interpretation to this point is in error, I trust you will correct me where needed.

--
73

Gary, N3GO

 

#52 : Update : The compact SLO formula for [AnyVNA]
-
after
https://groups.io/g/nanovna-users/message/5081 - 17 October 2019
https://groups.io/g/nanovna-users/message/5075 - 17 October 2019
by Gary O'Neil
-
@Gary O'Neil:

Dear Gary,

Thank you very much for your most valuable comments !

Allow us, please, to ask you to give us enough time to prepare
our replies.

Meanwhile, take into account, please, that you already motivated us
to attempt to write a minimal set of statements, valid more-or-less
in ANY computer language having NO internal type of COMPLEX
variables and only a REAL one, regarding :

#42 : The compact SLO formula for [AnyVNA] - 12 October 2019
https://groups.io/g/nanovna-users/message/4747

in order to be ready for embedding them in ANY related program
by the interested reader of- and/or contributor to- this thread of
messages.

However, during the transferring of that formula to statements,
and after we found and corrected an existing typo in it, we
finally succeeded a further compactification of it, and thus
we updated it, as follows:

https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png

that is in a super-mini form most appropriate for this
particular work : Thank you - Please, stay tuned

Best regards,

gin&pez@arg

52#

 

#53 : Upgrade : The [LeastVNA]
-
after:
#48 : ann : update 3 of [LeastVNA] is withdrawn
15 October 2019
https://groups.io/g/nanovna-users/message/4945
-

Hello,

Allow us, please, to inform you that we just finished our research
regarding the [LeastVNA] description of [AnyVNA], which from
now on exists in our small objective world as the one given by
this 39 characters long expression:

https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png

Thank you very much indeed all of you who constructively
commented on this crucial matter !

Sincerely,

gin&pez@arg

53#