You could alternatively use the ArmorRating, ShieldStrength, and PointDefense effect types if you would rather have the defensive bonus show up as an increase in the ship's defenses, though I feel that Sansloi37's choice of jamming makes more sense as a defensive bonus for smaller ships.
You could also use the Multiplier bonus type rather than a flat bonus type if you don't want to get the bonus for free. A bonus which has the 'multiplier' type works on the base value and increases it by a factor of (1 + [value]); if the base value is zero, the bonus doesn't do anything, so you'd need to first add a component which increases the base value of the statistic affected by the bonus in order to see the benefit.