# Re: More ISSTC theory stuff

```Original poster: "Eastern Voltage Research Corporation" <dhmccauley-at-easternvoltageresearch-dot-com>

Very interesting.  I myself have a lot of experience with designing
microstrip versions of 1/4 wave transformers and similar.
Most of it involving matching 50 ohm impedance lines with large numbers of
planar antennas which are combined in parallel combinations which may result
in impedances of 10 ohms, etc... so the quarter wave transformer is a must!
I'll have to look at the some more.

Dan

> Hi all,
>
> I've been doing a lot of work on the theory of operation of ISSTCs... if
not
> the practice :'(
>
> I now think that the ISSTC can be simply modelled, if we assume it
perfectly
> tuned, as two quarter-wave matching transformers in series. (an untuned
> primary SSTC is just a single transformer.)
>
> I'm pretty sure that the resonator is a quarter-wave transformer, with
> characteristic impedance Zo equal to sqrt(L/C) or alternatively
2*pi*fres*L.
> And along similar lines I can argue that the primary circuit is another
> transformer of the same kind, with Zo calculated in the same way, although
I
> don't think it does impedance inversion as the resonator does.
>
> Radio guys use two quarter wave transformers of different Zo in series to
> match two widely different impedances, and maybe this can explain why the
> ISSTC works so well- the two stage approach does a better job of matching
a
> high streamer impedance to the <1 ohm output impedance of a high power
> inverter.
>
> Anyway there are equations for designing these transformers in the ham