On Tue, 10 Sep 2019 at 18:39, Reginald Beardsley via Groups.Io <pulaskite=
[email protected]> wrote:
I'm proposing collecting raw, unaltered data and using a statistical
analysis of that to determine what the calibration routines should do. I
am well aware that this has been done in various forms. But I always feel
more comfortable if I go back to first principles when solving a problem.
There are very often approximations made which are not described well and
may be significant in certain cases.
A few things you might want to be aware of Reg. Perhaps I have
misunderstood what
*1) Mating similar connectors *
There are several connector types which will mate, although they are not
identical
1) SMA, 3.5 mm and 2.92 mm (K connector)
2) 2.4 mm & 1.85 mm
When different types are mated, there¡¯s a discontinuity which has been
analysed and can be corrected for. There¡¯s a paper that does this for
1) 3.5 mm and 2.92 mm (K connector)
2) 2.4 mm & 1.85 mm
The author(s) looked at the correction for SMA, but concluded that the
variability on the semi-precision SMA connector was too large to make it
worthwhile.
*2) Polynomial fits*
The usual polynomial is certainly not based on any accurate physical model.
However, for almost any high-end commercial calibration kit below about 50
GHz, that is what you will be given. You *might* be given measured data
too.
Given the accuracy of the polynomial fit method *far* exceeds that
warranted for an SMA connector, I can¡¯t help feeling that coming up with a
physical model based an an SMA connector is of no practical use whatsoever.
Perhaps I have misunderstood your intentions.
Have Fun!
Reg
Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
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
