Steps towards photonic antennas

Summary form only given. Photonics are basically replacing conventional components, such as the coaxial lead that would have interconnected the antenna and electronics. In the replacement stage, the design of the electronics is largely, if not completely, unaffected by the photonics. A second step in the evolution, of which we are beginning to see signs already, is the integration of photonics with antennas. It is important to note that the term "integration" is being used here to refer to both physical as well as functional integration of the two technologies. By conveying a lower frequency IF over the photonic link, it is possible to remote 60 GHz antennas over tens of kilometers of distance. A defining feature of this stage is that it introduces new capabilities that were not possible in stage one. The third step in the evolution is a photonic antenna. In this stage the photonics performs the sensing of the electromagnetic field, thereby replacing conventional antennas. One or two examples of antenna designs along this direction have been reported at the Photonic Systems for Antenna Applications (PSAA) conference. At this stage, entirely new types of antennas would be possible, since photonics would permit sensing as well as remoting the RF field without any electrically conductive elements to interfere with the antenna pattern. This paper presents examples and status of work in each of the three areas discussed above.