Effective High-Frequency Capacity or CPE Coefficient

An effective capacitance, or, when a 1, an effective CPE coefficient may be obtained directly from the imaginary part of the impedance as 

When A = 1, the CPE coefficient Q becomes a capacitance, and equation (17.7) can be written 

In contrast to the complex capacitance described in Section 16.3, the effective capacitance described in equation (17.8) is defined to be a real number. 

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