Bipolar may refer to: Medicine Bipolar cell Bipolar cell of the retina Bipolar disorder Bipolar I disorder Bipolar II disorder Bipolar spectrum Astronomy Bipolar nebula, a two-lobed, axi ally symmetric nebula Bipolar outflow, outflow of ejected materials from both poles of a star Engineering Bipolar electricity transmission Bipolar encoding Bi-Polar (locomotive) Bipolar signal Bipolar violation Transistors Bipolar junction transistor (BJT) Heterojunction bipolar transistor (HBT) Insulated-gate… (More on Bipolar)