Constant phase element

In electronics, a constant phase element is an equivalent electrical circuit component that models the behaviour of a double layer, that is an imperfect capacitor (see double-layer capacitance).

Constant phase elements are also used in equivalent circuit modeling and data fitting of electrochemical impedance spectroscopy data.

A constant phase element also currently appears in modeling the imperfect dielectrics' behavior. The generalization in the fields of imperfect electrical resistances, capacitances, and inductances leads to the general "phasance" concept: http://fr.scribd.com/doc/71923015/The-Phasance-Concept

General equation

The electrical impedance can be calculated:

Z_{CPE}={\frac {1}{Y_{CPE}}}={\frac {1}{Q_{0}\omega ^{n}}}e^{-{\frac {\pi }{2}}ni}

where the CPE admittance is: $Y_{CPE}=Q_{0}(\omega i)^{n}$ and Q₀ and n (0<n<1) are frequency independent.[1]

Q₀ = 1/|Z| at ω = 1 rad/s

The constant phase is always −(90*n)°, with n from 0 to 1. The case n = 1 describes an ideal capacitor while the case n = 0 describes a pure resistor.

References

Kochowski, S; K. Nitsch (21 May 2002). "Description of the frequency behaviour of metal-SiO₂-GaAs structure characteristics by electrical equivalent circuit with constant phase element" (PDF). Thin Solid Films. 415 (1–2): 133–137. Bibcode:2002TSF...415..133K. doi:10.1016/s0040-6090(02)00506-0. Retrieved 22 October 2012.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

[1] Kochowski, S; K. Nitsch (21 May 2002). "Description of the frequency behaviour of metal-SiO₂-GaAs structure characteristics by electrical equivalent circuit with constant phase element" (PDF). Thin Solid Films. 415 (1–2): 133–137. Bibcode:2002TSF...415..133K. doi:10.1016/s0040-6090(02)00506-0. Retrieved 22 October 2012.