A loss of power due to the tendency of electronic circuits and components to resist the flow of current. In a resistive circuit the power dissipated is equal to I2R, where I is the current and R the resistance. This is I2R loss. In an inductor or capacitor the dissipation factor is the cotangent of the phase angle, α, or the tangent of the loss angle, δ. In low-loss components it is almost equal to the power factor, cos α, and can be given approximately by σ/2πfε, where σ is the conductivity, ε is the permittivity of the medium, and f the frequency.
Dissipation causes free oscillations to be damped and removes the sharpness of cut-off in filters. High-frequency industrial heating is made possible because of dissipation of eddy-current energy in conductors (see induction heating) and displacement-polarization energy in dielectrics (see dielectric heating).
A network that is designed to absorb power is a dissipative network, as compared to a network that attenuates by impedance reflection. All networks provide some dissipation since entirely loss-free components cannot be made.