Add a new Feature?

[dl4raj]

Hi Bob and the list,

what do you think about adding a little new feature
to the next sw release:
I believe it would quite useful and time saving if the aim sw would calculate the the value of a component (in µH or pF respectively) which would be needed to compensate the imaginary part of a measured complex impedance (in series as well in parallel equivalent circuit).

73
Clemens
DL4RAJ

[Bob]

Hi Clemens,

Do you mean something like a matching network for an antenna? There is a nice program with a link under the "utility" tab that will do this when you're connected to the internet.

--73/Bob

[dl4raj]

Hi Bob,

no,I thought much more simpler.
If you have an antenna not very far from resonance,
R is not too much off 50 Ohm.
In this case it would just suffice to tune out the reactance.
Aim gives the reactance in Ohm.
So I thought it might be convenient to have the conjugate reactive Ohm value which would be needed for tuning out the reactance, presented in pF/µH at the frequency of interest.
Or in simpler words:
which L or C do I need to tune out the reactance?

I know the WY2u program.
Of course it offers perfect matching solutions for
lossless components.
BTW it's based on the original by John Whetherel (1997)

bwrc.eecs.berkeley.edu/Research/RF/projects/60GHz/matching/ImpMatch.html

WY2U has removed some minor bugs in his version
but has a Q issue (which is not the case with the original).
He calculates Q only from the load itself (X/R) but ignores
loaded Q of the matching network which is essential for
bandwidth and loss estimation.
See also
E. Wingfield, “New and Improved Formulas for the Design
of Pi and Pi-L Networks,” QST, Aug 1983, p 23.

73
Clemens
DL4RAJ

[dl4raj]

Aug 29, 2008 15:30:06 GMT -5 dl4raj said:

....Or in simpler words:
which L or C do I need to tune out the reactance?
....

73
Clemens
DL4RAJ

This additional info (beside the Ohm value) would also give a more quantitative feeling
of the needed reactance for compensation.
For most of us I think it's easier to imagine µHs or pFs than
e.g. +/- 300Ohm at xx MHz

73
Clemens
DL4RAJ