The Force Amplifier is a mod to increase the amount of damage done by a single attack from your portal. This mod is seen as a defensive mod and combined with a portal shield and the Turret mod it can really become hard if not nearly impossible for a member of the opposing faction to destroy your portal. As of this date, the only available class of the Force Amplifier is the rare one, so we cannot give you information about the whole package at this moment.
Force Amplifier stats
Every deployed Force Amplifier will increase the attack damage of the portal. The first rare Force Amplifier gives an increase of 100%. Each additional Force amplifier gives less and less benefit making it less beneficial to deploy more of these mods.
This page will get updated once Niantec releases more info
Damage Output per Deployed Force Amplifier
The increase of attack power per deployed amplifiers declines, so you don’t get another 100% increase on attack damage if you deploy a second Amplifier. This is a way to make sure the portals don’t get too powerful.
First Force Amplifier: 100% increase;
Second Force Amp: 50% increase;
Third Force Amp: 25% increase;
Fourth Force Amp: 12.5% increase;
Meaning that only the first one is really significant, because you get a total damage output of 200%. If you would deploy all four, the total damage output would only become 287.5%
eXact Matter Usage
Common Force Amplifier: 400 XM
Rare Force Amp: 800 XM
Very rare Force Amp: 1000 XM