I like to connect my laptop to an external monitor and close my laptop's lid. However, I noticed something. According to internet speedtests (and my personal knowledge from downloading large files), my wireless networking speed is nearly 10X faster when my lid is open than when my lid is closed (or more!). How do I make it so my speed is just as fast when the lid is closed?

NOTE:
In an internet speed test with the lid open I got about 20 Mbps down.
In an internet speed test with the lid closed I got about 2 Mbps down.

NOTE:
I am using a Gateway NE56R41u if that helps. The Gateway NE56R41u is not Ubuntu certified. It has a Broadcom BCM4313.