Air Core Inductors1 min read
Bay note 12 — Air core: linearity without a ferrite
No core loss, no saturation, more turns — when air-core inductors earn their board space in RF and precision paths.
Remove the ferrite and you remove B-H curvature and core loss. You pay with turns, size and a field that still exists in air.
When air-core is the point
- RF / resonant tanks where ferrite loss or µ drift hurts
- Precision paths that cannot tolerate µ(T) drift
- Very high frequency where many ferrites misbehave
Sizing note
Air-core AL is small — inductance is mostly geometry. We design from envelope and turn count, then measure L and Q at the frequency you care about.
What to put on the print
- L, Q or Rac at frequency, current
- Max OD/height, lead style
- Frequency of interest
See air core inductors.