Ghostrunner

The "beacon shield" is the blue glowing shield around enemies that is powered by a nearby sphere. Instead of destroying the sphere to disable the shield, use an ability to kill them through it. The first ability you gain (Blink) will do it, and you can reset a checkpoint if you want to quickly get it out of the way.

If you're looking for a spot, the first enemies in level 3 ("The Climb") have shields, but be aware that killing the first one triggers a checkpoint. Your best approach there is to get to that enemy (it takes a little while, but you need most of that time to charge up anyway), make sure your ability is fully charged so that the checkpoint will save you in the fully-charged state, and then kill the first one normally. Then you'll have a checkpoint with a fully-charged Blink and a shielded enemy right in front of you. Kill, reset checkpoint, repeat.