Give a look on the upper right of this page (entire page), you will see a picture of the R52 mPCI card.
Click on it, you will be redirected to the shop section. You will see a "Description" button on the bottom of R52 (and R52H) section. Click on it and you will get the tech spec on PDF format.
This document warns that the amplifier could be damaged if no antenna is connected. What is a safe TX power to use while testing on the bench? Its not always easy to attach antennas when you are just configuring the boards.
I assume if the card is disabled there is no risk to the amp circuits?