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37 : The [LeastVNA]

@Gary O'Neil - 6 October 2019 : /g/nanovna-users/message/4194

35 : Straight In The Heart of The Matter - 6 October 2019
/g/nanovna-users/message/4184

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Dear Gary,

Swell !

We already wrote a detailed draft, as a reply to your
interesting message above, of equal if not more length than that
and we will send it sometime later.

However, we have to interpreter your lengthy message as a kind
of manifestation of hesitation by you - not at all an
unjustifiable one ! - to accept our [AnyVNA] description, that
is of what you already called it "any" VNA, which signifies a
lack of consensus from your side to accept unreservedly that:

"Primarily, [AnyVNA] measures ( Amplitude Ratio , Phase
Difference ) couples in terms of Frequency"

because, according to you:

"More precisely, any VNA measures amplitude vs. frequency, and
either measures or computes phase in accordance with the
architecture of its design"

in which you drop the [Ratio] and [Difference] terms and
exclusively or-ed the measurement with computation, that is
- in our humble opinion - you reduce the Vector Network Analyzer
to a Scalar one, and most importantly, you cancel your attempt
to separate "hw" from "sw" and/or "fw".

After that, because our point of view stays constantly as a
facupov one, that is : From A common User's Point Of View, and
because we trust you, we accept your reservations regarding the
phase in the different ways of "any VNA" realization, and while
we are waiting your full explanations on why your modifications
increase the precision of your "any VNA" description, we
decrease right now our expectations from [AnyVNA] to [LeastVNA],
but we greatly increase its description by giving even more
details as follows - always facupov:

The [LeastVNA] :

(a) has at least one port realized by an external connector
with two sides : an internal and an external ones,

(b) uses an either internal or external device plus internal
circuitry in order to separate two cosinusoidal waves of the
same frequency coexisting at least into its port and beyond
that internally : an Input to- and Output from- the port,
caused by one-or-two coexisting signals at the external side
of its connector,

(c) measures in a range of frequencies "whatever needed" to
form a couple of two dimensionless quantities :

( Amplitude Ratio , Phase Difference )

between two cosinusoidal signals of the same frequency
resulting from- and analogous to- these two Input and Output
waves, respectively, as the first and second operands in these
formed division and subtraction operations,

(d) indicates these two quantities to its user,

(f) provides the user with a conceptual "error" model, that
is with a set of a rather small number of rather simple
algebraic equations, connecting the measurement of any load
with unknown or "known" nominal value Gamma with its indicated
value gamma,

using intermediately three 3 parameters "S", obviously
determinable by measuring three 3 "standard" loads of "known"
nominal value, with obviously the same indications in this
range of frequencies, independently of any other load of
unknown nominal value,

that is, after 4 = 3 + 1 measurements in total,

BUT :

(g) does not provide its user with the means to complete his
measurements because it ignores the uncertainty of these
three 3 "standards" and the inaccuracy of these 8 = 4 x 2
indications.

And we are basing our today description on that 51 years
old simplification - perhaps in the first ever publicly known
related paper - that is:

"is simply a microwave frequency vector ratio voltmeter",

given by Richard H. Hackborn at 'An Automatic Network
Analyzer System', Microwave Journal, May 1968, p.46.

However, yes, indeed. Our research has to do with an investigation
of the possibility of founding a seeing facupov of [AnyVNA] through
[LeastVNA] from now on, or equivalently, after your apt comments,
to see it conceptually. Therefore, we think that we have your
unreserved consensus to this sharable point and thus we put this
Very Cause into our small objective world, that is into our "sow"
from now on.

Please, stay tuned !

Kind regards,

73

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

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