Deflector shield

**Deflector shields**, often referred to simply as shields, were a technology that projected a type of electromagnetic force field around a starship, space station, or planet as a defense against enemy attacks or natural hazards.

A shield system had two components: the control system and the emitter. The control system was the software that provided both automatic functionality and manual control of shield frequencies and adaptation. The emitter, or generator, was the physical component that projected the forcefields. These were generally arranged in arrays or grids to provide full or overlapping coverage.

## Shield types

### Metaphasic

Invented by Ferengi scientist Dr. Reyga in 2369, metaphasic shielding was an upgrade to multiphasic shielding. This new type allowed starships to withstand the pressure, radiation, and energy of a star's corona. The shielding became standard on Starfleet vessels beginning in 2373 with the Reyga Metaphasic Shield Program.

### Multiadaptive

Multiadaptive shielding was a form of stealth technology that cycled a starship’s shield frequencies to match surrounding stellar radiation and phenomena to hide the starship from sensors.

### Multiphasic

Shield systems with multiphasic properties protected a vessel and its crew from subspace radiation and the harmful energy emissions of stars. It was developed by Starfleet in the late 23rd century.

### Multispectrum

Introduced with the *Intrepid*-class in 2370, multi-spectrum shielding

### Nexus Defense Screens

After the Nexus Incident of 2371, Geordi La Forge led a team to develop shielding technology that would protect starships from the effects of the Nexus and similar phenomena. Completed in 2376, Nexus Defense Screens (NDS) became standard on Starfleet vessels.

### Portcullis Portal Prevention Field

Developed by the Iconian Resistance toward the end of the Iconian War, the Portcullis Portal Prevention Field (3PF) prevented the formation of Iconian portals within a starship or facility using the program. Unlike many other shield types, the 3PF was constantly running to safeguard vessels and their crews.

### Refractive

Refractive shields allowed a vessel to remain invisible to conventional sensors.

### Regenerative

Regenerative shielding was developed to counteract enemy weapons fire. Shield systems with regenerative properties had integrated sensors to detect and analyze weapons frequencies. The system would then modulate the shield frequency to mitigate damage along those frequencies without depleting shield energy.

### Temporal

Temporal shields were developed to counter weapons in temporal flux and protect against external changes in the time stream.

### Unimatrix

Lieutenant Commander Tuvok, then serving aboard the USS *Voyager* stranded in the Delta Quadrant, invented unimatrix shielding after examining Borg technology. It was a lesser form of the Collective's adaptive shielding.

## Appendices

### Connections

**Propulsion systems:** Impulse • Quantum slipstream • Subspace conduit • Warp

**Science and remote sensing systems:** Sensor

**Tactical systems:** **Deflector shield** • Disruptor • Dynamic Tactical System • Launch tube • Phaser (array • bank • cannon • pulse cannon • turret)

**Utility systems:** Emergency holographic program • Modular Rapid Deployment System

**Mission pods:** Equipment pod • Habitation pod • Tactical pod (Weapon pod) • Transport pod

### Sources consulted

* Deflector shield article at *Memory Alpha*.
* Deflector shield article at *Memory Beta*.
* Ship Shields article at the *Star Trek Online Wiki*.