This article from Itchen Valley Amateur Radio Club describes an interesting technique called "Norton's transform":

enter image description here

This results in a negative capacitor, but in a circuit where there are other parallel capacitors which can be combined, the result can be positive and thus realizable. My particular interest is in filters.

Unfortunately I can't find any other information on "Norton's transform". Of course there's Norton's theorem of which I have a simple understanding, and while I wouldn't be surprised if the two are related, it's not immediately obvious to me how.

Is there a simple explanation of how this works? And can it be generalized to provide a similar impedance transformation in other circumstances, such as with inductors, or shunt components?

  • 1
    $\begingroup$ If you search for "Norton's transformation" (in quotes) you'll find a bunch of PDFs that might be helpful. $\endgroup$ – user3486184 Feb 20 '18 at 22:44

An excellent description is here: https://en.wikipedia.org/wiki/Equivalent_impedance_transforms

Sorry, I do not have sufficient brainpower to summarize :-)


Negative capacitance can be substituted with inductance at a single AC frequency. Since impedance wise they are opposites. That goes with replacing the transformer if it has more impedance then the caps. I'm fussy on the transformation, the math for all that eludes me most days.

I'm actually seeing this transformation attributed to Darlington, not Norton.
Christopher Morgan K8NVH's wikipedia article on Equivalent impedance transforms A History of Network Synthesis and Filter Theory for Circuits Composed of Resistors, Inductors, and Capacitors


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.