The gain, or increase in signal power, resulting from the insertion of a component, such as an amplifier or repeater, in a circuit. Insertion loss is measured as a comparison of signal power at the point the incident energy strikes the component and the signal power at the point it exits the component. Insertion gain typically is measured in decibels (dB), although it also may be expressed as a coefficient or a fraction. A negative gain is a loss. See also attenuation, dB, and insertion loss.