A phase discriminator is a device used to regulate the flow of energy fields. Using a phase discriminator, one can create a selectively permeable screen, allowing some objects/particles/EM waves to go through whilst blocking others whose phase properties are undesirable.
These devices have a variety of applications:
- positronic decompiler of the Soong-type androids
- Data has a type R phase-discriminating amplifier. (TNG : Time's Arrow)
- Lore has a type L phase-discriminating amplifier. (TNG : Time's Arrow)
- Starfleet Emergency transporter armbands contain a type-7 phase discriminator. (TNG: "Timescape")