BalunA balun is a device that is used to convert between balanced and unbalanced electrical signals. Balanced signals have two conductors, with the signal being carried on the difference between the two conductors, while unbalanced signals have a single conductor and a ground. Baluns are commonly used in radio frequency (RF) and other high-frequency applications, where balanced and unbalanced signals are used in different parts of the system. In the context of MOSFETs (metal-oxide-semiconductor field-effect transistors), a balun may be used to convert a balanced RF signal into an unbalanced signal that can be applied to the gate of the MOSFET, or to convert the unbalanced output of the MOSFET back into a balanced signal.