User Tools

Site Tools


fractal_inductor

Fractal inductor

Stan Zurek, Fractal inductor, Encyclopedia Magnetica,
http://www.e-magnetica.pl/doku.php/fractal_inductor

Fractal inductor1) (also fractal loop inductor2)) - a type of inductor made by shaping an electrical conductor in a pattern resembling mathematical fractal.

→ → →
Helpful page? Support us!
→ → →
PayPal
← ← ←
Help us with just $0.10 per month? Come on… ;-)
← ← ←
Example of fractal inductors3)

In high-frequency electronic circuits (up to GHz range) inductors can be made as a single-turn loops, for instance deposited as a thin layer of conductor (even below 1 µm) on a substrate.

In a planar arrangement, spiral inductors require at least two layers, or an out-of-plane return connection.

A single-turn loop inductors can be made within a single layer of conductor, but they might require significant surface area (footprint) to represent sufficient value of inductance. Fractal inductors are capable of representing increased value of inductance without increasing the footprint.

A higher-level fractal will have more features fit into the same space. For instance, the 3O fractal is equivalent to three base features positioned in a shape resembling the base configuration.4)5)

In the study presented by Shoute and Barlage6) the inductance of the base structure was 4.6 nH with resistance of 5 Ω. However, the values for the 3rd-3O configuration was 44.7 nH (increase by 9.7x) and 63.5 Ω (increase by 12.7x), respectively. According to the authors the self-inductance (due to increased length of conductor) does not sufficiently explain the increase, which must be due to some amount of mutual inductance between the neighbouring lobes of the structure. Even some professional modelling electromagnetic software is unable to model this effect seen in experiments.7)

Fractal inductors can exhibit Q factor greater than 40 at the operating frequency. The actual design depends on the type of fractal pattern used, as well as compromises in the design process (e.g. joining the neighbouring lobes). From practical viewpoint it might be more beneficial to implement fewer lobes (thus easier to manufacture) which would give equivalent inductance as more intricate pattern. This less-than-ideal behaviour can be referred to as fractal dilution.

Fractal inductors are especially useful for single-layer applications, and can be used on flexible or stretchable substrates.8) A patent application for this technology was submitted.9)

The fractal approach can be also applied to other devices: fractal transformer and fractal capacitor.

See also

References

This website uses cookies. By using the website, you agree with storing cookies on your computer. Also you acknowledge that you have read and understand our Privacy Policy. If you do not agree leave the website.More information about cookies
fractal_inductor.txt · Last modified: 2023/09/04 14:49 by stan_zurek

Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 4.0 International
CC Attribution-Share Alike 4.0 International Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki
Legal disclaimer: Information provided here is only for educational purposes. Accuracy is not guaranteed or implied. In no event the providers can be held liable to any party for direct, indirect, special, incidental, or consequential damages arising out of the use of this data.

For information on the cookies used on this site refer to Privacy policy and Cookies.