Realistic implementation of ellipsoidal reflector antennas to produce near-field focused patterns

The radiation characteristics of ellipsoidal reflector antennas in the near zone of antenna aperture are investigated using Physical Optics (PO) approximations. This antenna has potential applications in the near-field communications because its radiation focuses in the near zone. Analytical formulations to predict the radiation efficiency and exhibit field phenomena are developed. Its applications as a RFID reader antenna at 2.4 GHz are demonstrated by numerical simulations and measurements over a realistic implementation of offset reflector fed by a microstrip patch antenna. Both numerical and experimental studies are performed to validate this antenna design. Copyright © 2011 by the American Geophysical Union.