Phase Shift armor

In the Cosmic Era, Phase Shift armor is a technology designed to protect mobile suits from physical attack.

Phase Shift, or "PS" armor, is formed by millions of nano-robots that provide protection by changing their physical properties. When PS armor powers up, a hissing sound can be heard and the grey surface of the mobile suit's armor is overlaid in color, which appears to be alterable by entering different values in the Armor Voltage section of the OS. Once powered up, the PS armor consumes minimal energy unless it is being actively attacked. ZAFT commander Andrew Waltfeld, after watching the strike fight, estimated that the GAT-X105 Strike in standard use can take approximately 72 hits from TMF/A-802 BuCUE's missiles, before the energy usage drains the battery. Against the 76.2mm assault rifle carried by the ZGMF-1017 GINN, the Strike Gundam's armor is effectively unlimited.

A different theory is based on quantum mechanics which, although not fully understood in the CE universe, is understood far better than it is today and is applied in several other aspects. Phase shift of a trig wave is simply a x-value shift. Phase shift in matter refers to leptons, a broad category of wavicles (something which has properties of both waves and particles) that includes photons and electrons. When their phase is shifted they change into a different wavicle. Certain machines inside the armor change photons which are are in abundance because of ambient lighting and because other parts of the armor make some light. Now there is an abundance of electrons creating a strong negative charge to the armor (far stronger than what could be achieved with an electric current) and since all matter has an electron cloud, the outside edge of the weapon and armor never really touch. Beam weapons, which are composed of plasma (positive charge), are atracted to the armor and the extra electrons do not protect the Mobile Suit. The largest consumption of enegy occurs during start up because so many electrons must be created. Large drains occur when protecting against missiles and other explosives because that force strips lots of electrons off forcing the armor to create more. Beams also drain it because their positive ions attract some of the electrons again forcing the armor to make more. Running time even when not under attack is, although much longer, not infinite because the negative electrons dissapate and stray photons can also remove electrons.

Phase Shift armor (PS) was developed by the Earth Alliance, and first rolled out in Cosmic Era 71. It remains in use as of CE 73. The first mobile suits to be equipped with PS Armor are the so-called "Gundams", GAT-X102 Duel, GAT-X103 Buster, GAT-X105 Strike, GAT-X207 Blitz and GAT-X303 Aegis. Later, both ZAFT and the Orb Union's Morgenroete were able to study and duplicate the armor design.

The inverse of the Phase Shift armor concept is the Universal Century's I-field generator, which defends against beam weaponry but has no effect against physical attack.

Limitations
Because PS armor draws energy off of a mobile suit, the suits so equipped must have a means of replenishing that energy, or risk power depletion. During the war, the existence of N-Jammers limited mobile suits and mobile armors to operation on an energy battery (some mobile suits were equipped with various turbine engines to extend their operating time, but almost none had truly unlimited operational ability).

PS armor grants near-invulnerability to projectiles, but it has virtually no effect on beam weapons, so most PS armored mobile suits carry a shield with an ablative anti-beam coating for defense against beams.

Nuclear power could give a PS armored mobile suit theoretically unlimited operating time, however during the Bloody Valentine War the widespread use of N-Jammers made this nearly impossible and afterward, the Treaty of Junius outlawed nuclear-powered mobile suits. Only a few nuclear-powered mobile suits were made in any event, including the YMF-X000A Dreadnought, ZGMF-X09A Justice, ZGMF-X10A Freedom, ZGMF-X11A Regenerate,ZGMF-X12A Testament Gundam, ZGMF-X13A Providence, ZGMF-X999A ZAKU Trial Type, and during the Second Bloody Valentine War the ZGMF-X19A Infinite Justice and ZGMF-X20A Strike Freedom. Each of these units incorporated an N-Jammer Canceller in their design, negating the effects of the N-Jammers in the field.

Trans Phase Shift Armor
During the war, OMNI Enforcer experimented with ways to extend the usefulness of PS Armor, leading to the development of Trans Phase armor (TP), which improved on PS Armor by only activating at the point of impact. However, this left TP armored mobile suits vulnerable to heavy attack from multiple vectors (a sufficiently powerful weapon could also overpower the TP armor). Orb's Morgenroete, Inc. produced a similar Phase Shift system to armor the cockpit of the refitted MBF-P03 Astray Blue Frame Second L. While this armor was not referred to as Trans Phase, it was functionally identical. Extensive usage of Phase Shift armour, however, consumes a lot of energy, and so cannot be used for a long time

Variable Phase Shift Armor
ZAFT continues to develop Phase Shift armor after the war (the Earth Alliance seems to have abandoned it for the less power intensive Trans-Phase armor and conventional laminated armor) culminating in the development of Variable Phase Shift (VPS) Armor on the ZGMF-X56S Impulse, which alters the color and strength, and by extension the power consumption, to fit the suit's different configurations. Later on in the war the ZGMF-X42S Destiny, ZGMF-X666S Legend, ZGMF-X19A Infinite Justice and the ZGMF-X20A Strike Freedom would also use this technology to great effect.