Topics

errors of "error" models

erik@...
 

On Tue, Nov 5, 2019 at 05:48 AM, gin&pez@arg wrote:
Dear gin&pez@arg
How are you sure the errors to be corrected are larger than the uncertainty in your measurement. e.g. you are not trying to correct an already (almost) perfect VNA?

--
Erik, PD0EK

 

#73 :

erik@... - 5 November 2019 : https://groups.io/g/nanovna-users/message/6495

Dear Erik,

Thank you very much indeed for your interest in our work and also for the
chance you give us to explain it -always facupov, of course- further !

Therefore, regarding your specific question:

"How are you sure the errors to be corrected are larger than the uncertainty in
your measurement. e.g. you are not trying to correct an already (almost) perfect
VNA?"

allow us, please, to definitely clear without any doubt that in our sow [#24], [#34]
we are only * c u r r e n t l y * sure for the following - but we hope to excuse us
because, maybe unfortunately enough, we selected to explain all that using
purposely a greatly emphatical language:

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

(0) "A perfect VNA" is an object of the * i m p e r f e c t * world of mathematics

(1) "An already (almost) perfect VNA" may be an object in other subjective worlds
- we don't know, but we are ready to include it in our sow, as soon as we will be
provided by the specific quantitative data of its existence

(2) "The Least VNA" is simply AnyVNA that is used as a Reflectometer or
Impedance Meter in terms of frequency of One-Port devices using the well-known
("standard", 'Standard' or Standard) set of three 3 loads {S, L, O}, all with known
nominal values given respectively, not at all by us but by their manufacturers, as
the so-called "{-1, 0, +1}" or whatever similar

[ but loosely, because this may be result in a * B I G * source of misunderstanding
[ since this "set of values" is in fact the one of the couples of values:
[
[ { ( 1 , -180 ) , (0 , undefined ) , ( 1 , 0 ) }
[
[ in terms of their ( modulus , argument ) ordered
[ -
[ that is in order to avoid to mess up the things, the modulus value has always to
[ appear first, after the opening left parenthesis and before the separating comma,
[ and then the second argument value to appear before the closing right parenthesis
[ -
[ pairs or couples of values

although a last -apt, as usual- comment made by our Fellow in Knowledge Garry
O' Neil, N3GO [1], forced us to already think a possible reconsideration of this
definition in the direction of an even more simplification; always facupov, of course

(3) "The LeastVNA measured Impedance" is * I N * F A C T * an * I N D I R E C T *
"measurement", that is a * C A L C U L A T E D * or * C O M P U T E D * result,
just an * O U T P U T * of the well-defined * M A T H E M A T I C A L * function
expressed by the well-known * F O R M U L A * [#52]:

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

in terms of the measurements of these * T H R E E * loads, made * D I R E C T L Y *
using that * A N Y * V N A *

(4) Obviously this is an * I N S E P A R A B L Y * A S S O C I A T E D * to * A N Y *
* V N A * mathematical expression, a so-called "(mathematical) model", of this
very instance LeastVNA of that AnyVNA.

(5) We did * N O T * invent this relation [#52]:

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

We just simplified the given one [#16]:

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

-
as perhaps they did that others before us, although we don't know if something that
really happened.

This is easily verified by anyone who would like to use simple, high-school algebra
on these expressions, by ignoring their complex "nature" and substituting:

(i) g, G in Hellenic gamma, Gamma

(ii) -1, 0, 1 in A, B, C, and

(iii) s, l, o in a, b, c,

respectively, and proceeding with the resulting eliminations.

That's all.

(6) Now, since the 8 = 3 x 2 + 1 x 2 measurements s, l, o, and g, were indicated by
our VNA to us with a * F I N I T E *, * L I M I T E D * * A C C U R A C Y * of just
* T H R E E * 3 *, or * F O U R * 4 * at most, decimal * D * I * G * I * T * S *, it was
extremely natural in our sow to ask ourselves :

HOW BIG WILL BE THE EFFECT IN THE UNAVOIDABLY * C O M P U T E D *
IMPEDANCE, IF WE WOULD TAKE INTO ACCOUNT THAT *J U S T * O N L Y *
O N E *, THE LAST ONE, DIGIT OF THESE FOUR MEASURED VALUES WAS IN
DOUBT ?

THAT IS AS IT HAPPENS IN ANY OTHER MEASUREMENT, BY ANY OTHER
INSTRUMENT, SO WHY NOT WITH THOSE BY AnyVNA OR OUR VNA ?

That's all..

And, once again, definitely this has nothing to do with the perfectness or imperfectness
of AnyVNA itself. But, this definitely has to do with the unavoidably finite number of
reliable digits used by AnyVNA to indicate its measurements.

And this finite number of reliable digits in these four 4 measurements is only JUST
ONE source of error in the finally COMPUTED indirect "measurement".

(8) We emphasized in the above the COMPUTED character of the indirect
"measurement" because, if this INDIRECT "measurement" was a usual DIRECT
measurement, all the doubt would unavoidably restrict to just a few, perhaps even
only the last one, of its resulted digits - but, unfortunately enough, this is not the
case here.

(9) Also, and in addition to all that, the range of measured values (small, less than one
1 in modulus), as well as the particular form of the unavoidable mathematical
expression (ratio of differences of small, less than one 1, in modulus values) FORCED
us to attempt such a research
-
and it would be the GREATEST of OMISSIONS by us, if we did not act in this way,
as long as we declared ourselves not only as "researchers" but in addition as "scientific"
ones...

(10) After all that said, we think that we are ready to answer your question as follows:

- We are NOT interested to correct our "measurement" -in fact one of our VNA itself

- We are NOT interested if the errors to be corrected -in fact ones of our VNA itself-
are larger than the uncertainty in our "measurement" -in fact in the computed indirect
"measurement" of our VNA itself

- We are only * c u r r e n t l y * s u r e * that our method of estimation of the above
inaccuracy errors, which * U N A V O I D A B L Y * C O N T R I B U T E * to the
ENTIRE "MEASUREMENT" UNCERTAINTY of our two VNA systems
-
that is either of our VNA or of our * N a n o V N A *, * P L U S * our THREE Standards
and just in this, the simplest of all the possible cases, also "currently the simplest",
after our reservation (2) above, that is after Garry O' Neil's comment

- We are * c u r r e n t l y * s u r e * that our method of estimation of all the errors we
are currently in place to recognize as REALLY EXISTING in AnyVNA measurements,
that is the above Inaccuracy Errors PLUS those definitely larger than these
Uncertainty Errors given to our three 3 Standards by their manufacturers, all together
count 8 + 3 x 2 = 14, contribute UNAVOIDABLY to the ENTIRE "MEASUREMENT"
UNCERTAINTY of our two VNA systems

And this is the reason we call them :

"The Uncertainty Core" - at least of our two VNA and NanoVNA Systems -

In conclusion:

* UNCERTAINTY * LESS * THAN* THAT * IS * ENTIRELY * IMPOSSIBLE *

in AnyVNA SYSTEM and at least in its LeastVNA application - fullStop.

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

* You * Have * Been * Warned *

REFERENCES

[1] Gary O'Neil , N3GO - 4 November 2019 :
https://groups.io/g/nanovna-users/message/6432

[#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

[#24] : The Main Frame of a Possible Communication - 1 October 2019:
https://groups.io/g/nanovna-users/message/3649

[#34] : Trying to Limit the Misunderstanding up to its Removal - 5 October 2019:
https://groups.io/g/nanovna-users/message/4108

[#52] : Update : The compact SLO formula for [AnyVNA] - 17 October 2019:
https://groups.io/g/nanovna-users/message/5100
https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png

With our Best of Regards,

73

Nikolitsa, OE3ZGN/SV7DMC and Petros, OE3ZZP/SV7BAX

: 73#

 

#73': On the sine qua non Core Uncertainty of AnyVNA - incl. NanoVNA - System
(the message #73 is withdrawn mainly because its conclusion is too weak)

erik@... - 5 November 2019 : https://groups.io/g/nanovna-users/message/6495

Dear Erik,

Thank you very much indeed for your interest in our work and also for the chance
you give us to explain it -always facupov, of course- further !

Therefore, regarding your specific question:

"How are you sure the errors to be corrected are larger than the uncertainty in
your measurement. e.g. you are not trying to correct an already (almost) perfect
VNA?"

allow us, please, to definitely clear without any doubt that in our sow [#24], [#34]
we are only * c u r r e n t l y * sure for the following - but we hope to excuse us
because, maybe unfortunately enough, we selected to explain all that using
purposely a greatly emphatical language:

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

(0) "A perfect VNA" is an object of the * i m p e r f e c t * world of mathematics

(1) "An already (almost) perfect VNA" may be an object in other subjective worlds
- we don't know, but we are ready to include it in our sow, as soon as we will be
provided by the specific quantitative data of its existence

(2) "The Least VNA" is simply AnyVNA that is used as a Reflectometer or
Impedance Meter in terms of frequency of One-Port devices using the well-known
("standard", 'Standard' or Standard) set of three 3 loads {S, L, O}, all with known
nominal values given respectively, not at all by us but by their manufacturers, as
the so-called "{-1, 0, +1}" or whatever similar

[ but loosely, because this may be result in a * B I G * source of misunderstanding
[ since this "set of values" is in fact the one of the couples of values:
[
[ { ( 1 , -180 ) , (0 , undefined ) , ( 1 , 0 ) }
[
[ in terms of their ( modulus , argument ) ordered
[ -
[ that is in order to avoid to mess up the things, the modulus value has always to
[ appear first, after the opening left parenthesis and before the separating comma,
[ and then the second argument value to appear before the closing right parenthesis
[ -
[ pairs or couples of values

although a last -apt, as usual- comment made by our Fellow in Knowledge Garry
O' Neil, N3GO [1], forced us to already think a possible reconsideration of this
definition in the direction of an even more simplification; always facupov, of course

(3) "The LeastVNA measured Impedance" is * I N * F A C T * an * I N D I R E C T *
"measurement", that is a * C A L C U L A T E D * or * C O M P U T E D * result,
just an * O U T P U T * of the well-defined * M A T H E M A T I C A L * function
expressed by the well-known * F O R M U L A * [#52]:

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

in terms of the measurements of these * T H R E E * loads, made * D I R E C T L Y *
using that * A N Y * V N A *

(4) Obviously this is an * I N S E P A R A B L Y * A S S O C I A T E D * to * A N Y *
* V N A * mathematical expression, a so-called "(mathematical) model", of this
very instance LeastVNA of that AnyVNA.

(5) We did * N O T * invent this relation [#52]:

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

We just simplified the given one [#16]:

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

-
as, perhaps, they did that others before us, although we don't know if something
that was really happened.

This is easily verified by anyone who would like to use simple, high-school algebra
on these expressions, by ignoring their complex "nature" and substituting:

(i) g, G in Hellenic gamma, Gamma

(ii) -1, 0, 1 in A, B, C, and

(iii) s, l, o in a, b, c,

respectively, and proceeding with the resulting eliminations.

That's all.

(6) Now, since the 8 = 3 x 2 + 1 x 2 measurements s, l, o, and g, were indicated by
our VNA to us with a * F I N I T E *, * L I M I T E D * * A C C U R A C Y * of just
* T H R E E * 3 *, or * F O U R * 4 * at most, decimal * D * I * G * I * T * S *, it was
extremely natural in our sow to ask ourselves :

HOW BIG WILL BE THE EFFECT IN THE UNAVOIDABLY * C O M P U T E D *
IMPEDANCE, IF WE WOULD TAKE INTO ACCOUNT THAT *J U S T * O N L Y *
O N E *, THE LAST ONE, DIGIT OF THESE FOUR MEASURED VALUES WAS IN
DOUBT ?

THAT IS AS IT HAPPENS IN ANY OTHER MEASUREMENT, BY ANY OTHER
INSTRUMENT, SO WHY NOT WITH THOSE BY AnyVNA OR OUR VNA ?

That's all..

And, once again, definitely this has nothing to do with the perfectness or imperfectness
of AnyVNA itself. But, this definitely has to do with the unavoidably finite number of
reliable digits used by AnyVNA to indicate its measurements.

And this finite number of reliable digits in these four 4 measurements is only JUST
ONE source of error in the finally COMPUTED indirect "measurement".

(8) We emphasized in the above the COMPUTED character of the indirect
"measurement" because, if this INDIRECT "measurement" was a usual DIRECT
measurement, all the doubt would unavoidably restrict to just a few, perhaps even
only the last one, of its resulted digits - but, unfortunately enough, this is not the
case here.

(9) Also, and in addition to all that, the range of measured values (small, less than one
1 in modulus), as well as the particular form of the unavoidable mathematical
expression (ratio of differences of small, less than one 1, in modulus values) FORCED
us to attempt such a research
-
and it would be the GREATEST of OMISSIONS by us, if we did not act in this way,
as long as we declared ourselves not only as "researchers" but in addition as "scientific"
ones...

(10) After all that said, we think that we are ready to answer your question as follows:

- We are NOT interested to correct our "measurement" -in fact one of our VNA itself

- We are NOT interested if the errors to be corrected -in fact ones of our VNA itself-
are larger than the uncertainty in our "measurement" -in fact in the computed indirect
"measurement" of our VNA itself

- We are only * c u r r e n t l y * s u r e * about our currently in use method of estimation
of the above inaccuracy errors, which * U N A V O I D A B L Y * C O N T R I B U T E *
to the ENTIRE "MEASUREMENT" UNCERTAINTY of our two VNA systems
-
that is either of our VNA or of our * N a n o V N A *, * P L U S * our THREE Standards
in just this, the simplest of all the possible uses of these (also currently "the simplest"
use, after our reservation (2) above, that is after Garry O' Neil's comment

- We are * c u r r e n t l y * s u r e * about our currently in use general method of estimation
of all the errors we are currently in place to recognize as REALLY EXISTING in AnyVNA
measurements, that is (a) the above Inaccuracy Errors, PLUS (b) those, definitely larger
than these, Uncertainty Errors given to our three 3 Standards by their manufacturers
-
all together count to finding 28 (real) numbers at most, by taking into account that all
these are in general (real) intervals with two 2 end-point numbers, a lower and an upper one,
so that 2 x (8 + 3 x 2) = 2 x 14 = 28
-
contribute UNAVOIDABLY to the ENTIRE "MEASUREMENT" UNCERTAINTY at least of our
two VNA systems, if nobody's else.

And this is the reason we call this component of the entire uncertainty:

"The sine qua non Core Uncertainty of AnyVNA - incl. NanoVNA - System"

In conclusion:

We are currently sure for that:

Facupov, * UNCERTAINTY * LOWER * THAN* THIS * CORE * UNCERTAINTY *
* IS * ENTIRELY * IMPOSSIBLE * in AnyVNA - incl. NanoVNA - SYSTEM under
its LeastVNA application, as well as,

We are currently sure for that:

Our current method of estimation of this Core Uncertainty is the only known one
as an objectively existing one, even as an object of just our sow - that is it has
a deterministic character - for more than ten years now.

Others may have their own methods of estimation of other types of uncertainty
components, as objects of their subjective worlds - that is they have a statistical
character.

However, facupov, currently we are definitely not interested either on those
uncertainty components or on their estimating methods - fullstop.

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

* You * Have * Been * Warned *

REFERENCES

[1] Gary O'Neil , N3GO - 4 November 2019 :
https://groups.io/g/nanovna-users/message/6432

[#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

[#24] : The Main Frame of a Possible Communication - 1 October 2019:
https://groups.io/g/nanovna-users/message/3649

[#34] : Trying to Limit the Misunderstanding up to its Removal - 5 October 2019:
https://groups.io/g/nanovna-users/message/4108

[#52] : Update : The compact SLO formula for [AnyVNA] - 17 October 2019:
https://groups.io/g/nanovna-users/message/5100
https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png

With the Best of our Regards,

73

Nikolitsa, OE3ZGN/SV7DMC and Petros, OE3ZZP/SV7BAX

:73'#

Gary O'Neil
 

Thank you GIN & PEZ



--
73

Gary, N3GO

Gary O'Neil
 

Thank you GIN & PEZ;

Your post #6529

#73': On the sine qua non Core Uncertainty of AnyVNA - incl. NanoVNA - System
(the message #73 is withdrawn mainly because its conclusion is too weak)

Seems to add significant clarity to my understanding of your project overall;

I will attempt a concise summary of my understanding, and seek your confirmation on this, or clearly illuminate those components of thought where I am in error.

The One port LeastVNA equation:

https://www.op4.eu/code/G-mini.c.gza.cc.by.4.0.2019.png [#52]

Is a reduced (one-port) expression derived from the full (two port) set of equations

https://www.op4.eu/code/cc-by-4.0-gz-ain-vna-params.png [#16]

and neither of these are new, but are based on the prior works of perhaps many.

The unique property of [#52], (and [#16] as well) is that they describe calibrations of any VNA using just the nominal measurements of the SOL standards, and any nominal DUT measurements from
which the desired DUT parameters are then computed.

An additional unique (and most important property) of the equations is that they do not attempt to correct for any source of uncertainty bias. Correction parameters are intentionally ommitted.

[#16], and [#52] as a subset, are declared the Core equations for any VNA calibration, and define the variables, and computational requirements common to any VNA (All VNA's) for the following reasons:
1) The measurements are performed identically for any VNA
2) The quanity of measurements and computations are identical for any VNA
3) ALL measurement uncertainties that are not common to ALL VNA's are excluded from the computations and results.
4) The equations enable measurements made on any VNA calibrated as a "system" to be compared equally without bias. All known unavoidable uncertainties are common to all VNAs, and are
absorbed equally and identically into the calibration as the overall uncertainty of the measurement system itself.

The Core uncertainty is defined as the unavoidable deterioration of computational precision created when multiplying and dividing by indeterminately large and small quantities, the accumulation of
round-off and truncation errors, and the unavoidable number of mathematical operations required to arrive at a computed final result.

The Core uncertainty, is a computational artifact, that is objectively deterministic, and defines the UNAVOIDABLE MINIMUM boundaries of uncertainty in any VNA, that can not be improved through
the use of higher precision equipment or components. This is the objective of the DERDEI software currrently in the form of a FORTRAN calculator and wxMaxima plotting utility.

In other words...

Sine qua non F(Any)CUPOV. :-)

73

Gary, N3GO

--
73

Gary, N3GO

erik@...
 

Dear GIN & PEZ
I must, unknowingly, have asked a very wrong question. Apologies for that.
The reason for asking was the simplification to the formula G=m/s
I was assuming, probably very wrong, that any simplification is based on the absence of impact of the factors that are being ignored.
You are able to calculate the uncertainty of the measurement so I was merely interested how the factors being ignored where in magnitude of impact compared to the magnitude of uncertainty of the measurement.
But if this is a stupid question please ignore it and do not spend any time to reply, only state: This is a stupid question.

--
Erik, PD0EK

Gary O'Neil
 

Hi Erik;

I was raised to believe that there is no such thing as a stupid question, but after several decades of not being exposed to the light, I discovered that there are actually many... All of them are the ones that never get asked. :-)

From my perspective at least, the question you asked was a brilliant one, as evidenced by the response it solicited. It is a struggle for me to capture much of the understanding I'm attempting to achieve through the many segmented and translated responses. Its only fair to assume that the reverse holds true for them as well. Their published documents on this are much better written English translations, but they don't stand on their own for all readers, and for those of us who have had limited if any exposure, are left with many unanswered questions.

We ask questions to get smarter. Very often it is helpful to hear "You don't understand." If we fail to ask questions that solicit such a response, we might well go through our lives with the truly stupid notion that "We must be pretty smart."; while in fact we have no understanding at all. :-)

Sometimes I ask questions that I believe I know the answer to very well, to verify my understanding. I am a married man, so I have learned that just because I'm confident that I have all of the right answers; most of the time they are entirely incorrect. LOL!

--
73

Gary, N3GO

 

@Erik, PD0EK - 6 November 2019:
https://groups.io/g/nanovna-users/message/6539

Dear Erik, This is not a stupid question. Best regards, gin&pez@arg

PS More on that by Gary, N3GO - 6 November 2019:
https://groups.io/g/nanovna-users/message/6566

 

#74: The Virtual Port - "Revealing" the Most Confusing "Secrets" of "Error" Models

Hello,

Allow us, please, to "reveal" that:

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

In our sow, every "error" model has at least one real load port and at least one
virtual measurement port.

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

Would you, please, think about it ?

Sincerely,

gin&pez@arg

:74#

 

#75: A Mechanical Production of the [LeastVNA] Description

Hello,

Allow us, please, to inform you that we just uploaded a mechanical
production of the [LeastVNA] description, at:

https://www.op4.eu/code/G-MINI-20191109.MC.txt

Sincerely,

gin&pez@arg

:75#

Gary O'Neil
 

GIN&PEZ@arg

Thank you for the derivation of the G-MINI equation, based on the embedded solution set of four simultaneous equations (GABC) to resolve the embedded value of G based on the measurements of the standards used for S, O. and L. I think I am following the reasoning in your thesis, or at least I understand and agree with the derivation, and I agree that all of the uncertainties are embedded in the measurements. It has also given me an appreciation for Maxima. I don't believe it is a tool that my Algebra and Calculus Instructors would have permitted me to employ in my exams. :-)

73

Gary, N3GO





--
73

Gary, N3GO

 

#76: The Big Three Free Software Tools Supporting The Independent Research
-
@Gary O'Neil, N3GO - 10 November 2019 :
https://groups.io/g/nanovna-users/message/6711

Dear Gary,

Thank you, since you are giving us the very rare chance nowadays to revise
all that 10+ years old work, to see its weaknesses, to try once again to fill its
gaps, to express new, improved, ideas
-
always facupov, about fundamental, considered as "well-known" concepts,
because, the Most Difficult Thing to Finally See is the Simplest One Standing
in Front of You
-
and to improve further our skills regarding:

The Big Three Free Software Tools Supporting The Independent Research

we are still using by combining their Symbolical, Numerical, and Graphical
abilities, that is respectively of:

[Maxima], [Open Watcom], and [GnuPlot].

Thank you very much, indeed.

Sincerely,

gin&pez@arg

:76#

 

#77: On the current explanation of full one-port "error" model
in our sow - facupov, as always - with an Application to the
Measurements of Two-Port Devices

Hello,

Well, after the previous related messages, we think that we are
now enough prepared to ask you to allow us, please, to attempt a
presentation of the current explanation of the so called full
one-port "error" model in our sow - facupov, as always.

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

In our sow, the full one-port "error" model is an Abstract or
Virtual Two-Port V2P located inside [AnyVNA] (incl. [NanoVNA])
and having as its ports the Virtual Measurement Port VMP [#74]
and the Real Load Port RLP.

This V2P is obviously characterized by the [LeastVNA]
description of G-mini:

G = (g-l)*(o-s)/[(g-o)*(s-l)-(g-s)*(l-o)]

Therefore, using the above concepts, we can measure, indirectly
- as in the case of one-port - : (a) either the S11, S12S21, and S22
parameters of any Two-Port Device appropriate to be connected
by the one port of its two ports to the RLP of the V2P and/or
(b) any unknown One-Port G' appropriate to be connected to the
other port of this Two-Port Device, using this very same G-mini:

G' = (g'-l')*(o'-s')/[(g'-o')*(s'-l')-(g'-s')*(l'-o')]

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

REFERENCE

[#74] The Virtual Port - "Revealing" the Most Confusing
"Secrets" of "Error" Models - 7 November 2019 :
https://groups.io/g/nanovna-users/message/6604

Sincerely,

gin&pez@arg

:77#

 

[ann] next-to-come : on the measurement of s-parameters using the [LeastVNA] only

 

D.M.Kerns and R.W.Beatty : "An understanding of this introductory microwave
network analysis is essential to the serious worker in the field of microwave
measurements. In order to investigate errors in measurements, one must have
in mind precisely what quantity is desired in the measurement. Basic definitions
of these quantities involve both explicit and implicit assumptions which must be
recognized. In addition a knowledge of these analytical tools should be helpful
in understanding error analyses already performed by others and described in
the literature.", Basic Theory of Wave guide Junctions and Introductory
Microwave Network Analysis, Part 2, Introductory Microwave Network Analysis,
2.0.Introduction to Part 2, p.34, Paragraph 3, International Series of Monographs
in Electromagnetic Waves, Editors: A. L. Cullen, V. A. Fock J. R. Wait, Volume
13, Pergamon Press Inc, First Edition, 1967.

 

#78: on the measurement of s-parameters using the [LeastVNA] only

- 12 November 2019 - https://groups.io/g/nanovna-users/message/6912 -

Hello,

Allow us, please, to inform you that we just uploaded the (indirect)
"measurements" of S11, S12S21, S22 of an unknown 2-port connected to the
[LeastVNA], as well as the (indirect) "measurement" of GL of an unknown
1-port connected to this 2-port, at:

https://www.op4.eu/code/s2p.png

where:

s, l, o and S, L, O are the [LeastVNA] measurements at the Virtual Port of
[LeastVNA], when the SHORT, LOAD, OPEN "standards", 'standards', or
Standards having Nominal Values -1, 0, +1 are connected at the Load Port of
[LeastVNA] and at the Load Port of the connected 2-port, respectively, while G
is the [LeastVNA] measurement of the GL connected to the same Load Port of
2-port.

Notably, only one-port reflection measurements are involved.

Sincerely,

gin&pez@arg

:78#

 

[ann] : [NanoVNA] ~ [LabVNA] comparison using a 2-port

 

#78' : #78 was corrected : https://www.op4.eu/code/s2p.png
-
#78: on the measurement of s-parameters using the [LeastVNA] only
18 November 2019 - https://groups.io/g/nanovna-users/message/7162

 

#79: Three Animated-GIF/AVIs in Slow Motion Demonstrate,
Step-by-Step, the Graphical Construction of Differential Error
Regions Arising in the Measurements with [AnyVNA]

Hello,

Allow us, please, to inform you that 11 years ago we uploaded 3
Animated-GIF/AVIs in slow motion demonstrating, Step-by-Step,
the graphical construction of the differential Error regions arising
in the Measurements with [AnyVNA], at:

1/3
http://antennas.gr/anamet/30/ani/gif/ico.gif
http://antennas.gr/anamet/30/ani/avi/ico.avi

2/3
http://antennas.gr/anamet/30/ani/gif/iico.gif
http://antennas.gr/anamet/30/ani/avi/iico.avi

3/3
http://antennas.gr/anamet/30/ani/gif/iiio.gif
http://antennas.gr/anamet/30/ani/avi/iiio.avi

Sincerely,

gin&pez@arg

:79#

 

#78'' : #78' was re-corrected : https://www.op4.eu/code/s2p.png
-
#78' : #78 was corrected : https://www.op4.eu/code/s2p.png
19 November 2019 - https://groups.io/g/nanovna-users/message/7185
#78: on the measurement of s-parameters using the [LeastVNA] only
18 November 2019 - https://groups.io/g/nanovna-users/message/7162
-
:78''#