Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

DC link inductor
an inductor used on the output of a controlled rectifier in AC current source drives to provide filtering of the input current to the current source inverter. If used in conjunction with a capacitor, then it is used as a filter in voltage source drives.
inductor
a two-terminal electrical element that satisfies a prescribed algebraic relationship in the flux-current (θ - I) plane.
spiral inductor
an integrated circuit implementation of a common electrical element that stores magnetic energy. Two extreme behaviors of an inductor are that it will act as a short circuit to low frequency or DC energy, and as an open circuit to energy at a sufficiently high frequency (how high is determined by the inductor value).

In an MMIC, a spiral inductor is realized by a rectangular or circular spiral layout of a narrow strip of metal. The value of the inductance increases as the number of turns and total length of the spiral is increased. Large spiral inductors are very commonly used as "bias chokes" to isolate the DC input connection from the RF circuit. Since a large valued inductor essentially looks like an open circuit to high frequency RF/microwave energy, negligible RF/microwave energy will leak through and interact with the DC bias circuitry.