Compact, high directivity, omnidirectional circularly polarized antenna array

Wei Lin, Richard W. Ziolkowski

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


A compact omnidirectional circularly polarized (OCP) antenna system is reported, which achieves high directivity and operates with the 2.4 GHz WLAN band. It is formed by cascading several stages of electric (metallic strips) and magnetic (loops) radiators into a highly compact array. Two OCP antenna array designs are developed to demonstrate the approach and their resulting high directivities. First, a four-stage OCP antenna array is presented. It consists of three electric radiators (E-radiators) and four magnetic radiators (M-radiators) arranged in collinear formation. A prototype was realized by mechanically fabricating the folded copper loops. Measurements confirm that this compact cost-effective design generates OCP fields that have a 5.1 dBic peak LHCP realized gain in its horizontal plane. The overlapped impedance and AR bandwidth cover 130 MHz from 2.34 to 2.47 GHz. Second, a six-stage OCP antenna array with helical loops is implemented to further increase the directivity. Its prototype was realized with all-metal 3-D printing technology. Six stages of bar and helical loop radiators form five E-radiators and six M-radiators. This highly compact OCP array achieves a measured maximum realized gain of 7.1 dBic with a 110 MHz operational bandwidth that covers 2.37-2.48 GHz.

Original languageEnglish (US)
Article number8668527
Pages (from-to)4537-4547
Number of pages11
JournalIEEE Transactions on Antennas and Propagation
Issue number7
StatePublished - Jul 2019


  • 3-D printing technology
  • antenna array
  • circular polarization
  • electric radiators (E-radiators) and magnetic radiators (M-radiators)
  • high directivity
  • omnidirectional patterns

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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