How does the Inductance and Impedance of an Inductor vary with Frequency?

1 Answer
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- everything RF

Sep 1, 2017

The response of inductance and impedance vs frequency can be seen in the graph below.

Frequency Response of an Inductor: 

  • At frequencies below the SRF, impedance and inductance increase with frequency. 
  • At the SRF, the impedance and inductance is at its maximum. 
  • At frequencies above the SRF, impedance and inductance decrease with frequency. 

The inductance only acts like an inductor up to its Self Resonant Frequency (SRF). At the SRF the impedance becomes very high and the inductor can be used as a choke to attenuate signals near at the SRF.