According to the VirtualBox documentation, the following (virtual) network adapters are implemented:
- AMD PCNet PCI II (Am79C970A)
- AMD PCNet FAST III (Am79C973, the default)
- Intel PRO/1000 MT Desktop (82540EM)
- Intel PRO/1000 T Server (82543GC)
- Intel PRO/1000 MT Server (82545EM)
- Paravirtualized network adapter (virtio-net)
None of these are wireless adapters so therefore your virtual machine will never see any of the 802.11 features. Additionally, even if VirtualBox did implement a wireless network card, it would never see any signals because it's not attached to a real radio.
In theory, you could get a virtual machine to see a wireless card through PCI or USB passthrough, but I have never tried that so cannot give an opinion about how well that works.