Printed Helix Antenna Research Articles

Circularly Polarized Printed Helix Antenna for L- and S-Bands Applications

Circularly Polarized Printed Helix Antenna for L- and S-Bands Applications

Design of multi‐layered polygonal helix antennas for RFID applications

AbstractIn this letter, we propose a novel printed helix antenna for an RFID reader in the UHF band. The printed microstrip line of the antenna is first wound outside a polygonal‐shaped layer and then wound on an inner layer to control the overall gain and the radiation pattern of the antenna. On each layer, the winding pitch angles can have either negative or positive values, which results in a circularly polarized (CP) broad bandwidth. The structural details of the antenna were optimized using the Pareto genetic algorithm (GA), which allowed for excellent performance with the use of RFID reader antennas. The optimized two‐layered polygonal helix was fabricated on a flexible cardboard substrate. Performances of the antenna were measured and compared with those of simulations. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1971–1974, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22595