I have ID 0846:9020 NetGear, Inc. WNA3100(v1) Wireless-N 300 [Broadcom BCM43231] I bought few years ago. I have to move my computer to apart of the house where Ethernet will not reach.
Try installing bcmwl-kernel-source first and see if that works.
sudo apt-get install bcmwl-kernel-source
Reboot your machine and see if the wifi works.
If not, someone in the ubuntuforums seems to have the solution.
I hope that works.