We provide a very broad outline for a new research area within the domain for Future Antennas, namely quantum antenna (q-antenna) theory and their applications to building secure digital communication lines. The proposed quantum antenna theory purports to presenting a natural extension of RF antennas in classical wireless to the now established field of quantum communications. The paper provides a bird's eye view on the subject, highlighting the main themes and the expected results and benefits of such research domain.
Due to the broadcast nature of wireless communication medium, more and more attention has been paid to the security problem in wireless communication system. Aimed at physical layer security issues in multi-antenna system, several common multi-antenna techniques are focused on, and the theory indexes are introduced to assess secrecy performance. The influence of different system parameters on the system secrecy performance is simulated and analyzed. Finally, the directions of physical layer security in wireless channel worthy of research are presented.