Abstract: An antenna system that allows increasing the reading reliability of RFId systems by dynamically changing the shape or the polarization of the electromagnetic field radiated by the RPId reader. The system includes at least one reconfigurable antenna, a variable DC bias unit and a methodology to efficiently use the system in RFId applications. The system allows changing the direction in which the energy is radiated or the polarization of the radiated field in order to “move” the electromagnetic field and to also read RFid tags that receive faint signals with standard RFid systems. Polarization alignment between the reader's antenna and the transponder allows for maximum power transfer, while changing the direction of radiation allows concentrating the electromagnetic field towards the transponder.

Abstract: Leaky wave antennas that can be reconfigured in pattern and/or polarization by exploiting the characteristic of metamaterial structures loaded with variable capacitor and inductors employ a Composite Right Left Handed (CRLH) unit cell with two independent DC biases used to actively change the group delay of the transmission line and the polarization of the radiated field while preserving good impedance matching. Different degrees of pattern and polarization reconfigurability are achieved by cascading multiple of these unit cells along a straight line, a circular line or a zigzag line while preserving high gain for all the antenna configurations and good impedance matching.

Abstract: An antenna system that allows increasing the reading reliability of RFId systems by dynamically changing the shape or the polarization of the electromagnetic field radiated by the RPId reader. The system includes at least one reconfigurable antenna, a variable DC bias unit and a methodology to efficiently use the system in RFId applications. The system allows changing the direction in which the energy is radiated or the polarization of the radiated field in order to “move” the electromagnetic field and to also read RFid tags that receive faint signals with standard RFid systems. Polarization alignment between the reader's antenna and the transponder allows for maximum power transfer, while changing the direction of radiation allows concentrating the electromagnetic field towards the transponder.