bipolar junction transistor
- noun a transistor constructed of three layers of alternating types of doped semiconductor (p-n-p or n-p-n).
- A semiconductor device which utilizes both electrons and holes as charge carriers. These have two pn junctions, and depending on their arrangement may form an npn or pnp transistor. Such transistors have three main regions, which are the emitter, base, and collector. Bipolar junction transistors are one of the two main classes of transistors, the other being field effect transistors. Used extensively in audio amplifiers and wireless transmitters. Its abbreviation is BJT, or bipolar transistor.