Broadband circularly polarized moxon based antennae for RFID and GPS

Haojiong Liu, Oksana Manzhura, Ibrahim Tekin, Edip Niver

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Novel circularly polarized (CP) VHF SATCOM antenna which was based on Moxon antenna (bent dipole element over a ground plane) has been extended for RFID and GPS applications. A sequence of topologies starting from a single vertical element to two vertical elements of the Moxon arms, then widened strip arm elements were investigated to understand the effects on impedance match over the widened bandwidth. The logic in this evolution was to obtain maximized gain based on Fano-Chu limits, which suggests that more metallization in the radiating configuration that fill the volume would yield higher gain for electrically small antenna. Extending the width of the strip of the equivalent dipole elements lead to a wider bandwidth and improved cross-polarization ratio. Furthermore, splitting the tapered bow tie elements increased the volume filled with radiating elements leading to improved overall performance. Ultimately extended bends at the tip of the tapered sections parallel to the ground plane helped to improve overall performance. In overall, the antenna presented here produced lower physical height, higher gain, wider bandwidth, better cross-polarization and lower back lobe radiation compared to commercial counterparts such as an eggbeater currently used in SATCOM practice as well as similar antennas in RFID and GPS applications. Here, the concept is extended to cover RFID (850-1050 MHz) and GPS (centered at 1227 and 1575 MHz) bands leading to new applications at a significant cost and size reductions and much improved performance. Prototype antennas were built based on HFSS simulations yielded better than -25 dB return loss. During simulations attention was paid to identify the effects of individual antenna elements as an optimization parameter on the overall input impedance matching over the extended bandwidth. Simulated and measured results yielded higher than industrial counterpart antenna gain, bandwidth and cross-polarization for much reduced physical dimensions.

Original languageEnglish (US)
Title of host publicationPIERS 2012 Moscow - Progress in Electromagnetics Research Symposium, Proceedings
Number of pages5
StatePublished - 2012
EventProgress in Electromagnetics Research Symposium, PIERS 2012 Moscow - Moscow, Russian Federation
Duration: Aug 19 2012Aug 23 2012

Publication series

NameProgress in Electromagnetics Research Symposium
ISSN (Print)1559-9450


OtherProgress in Electromagnetics Research Symposium, PIERS 2012 Moscow
Country/TerritoryRussian Federation

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials


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