US Patent 9490353 Three terminal PIN diode

This disclosure describes a switch having a collector, base, emitter, and an intrinsic region between the collector and base. The intrinsic region increases the efficiency of the switch and reduces losses. The collector, base, and emitter each have respective terminals, and an AC component of current passing through the base terminal is greater than an AC component of current passing through the emitter terminal. Additionally, in an on-state a first alternating current between the base and collector terminals is greater than a second alternating current between the collector and emitter terminals. In other words, AC passes primarily between collector and base as controlled by a DC current between the base and emitter.