The directivity of a compact antenna: An unforgettable figure of merit

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

When an electrically small antenna is conceived, designed, simulated, and tested, the main emphasis is usually placed immediately on its impedance bandwidth and radiation efficiency. All too often it is assumed that its directivity will only be that of a Hertzian dipole and, hence, its directivity becomes a minor consideration. This is particularly true if such a compact antenna radiates in the presence of a large ground plane. Attention is typically focused on the radiator and its size, while the ground plane is forgotten. This has become a too frequent occurrence when antennas, such as patch antennas that have been augmented with metamaterial structures, are explored. In this paper, it is demonstrated that while the ground plane has little impact on the resonance frequency and impedance bandwidth of patch antennas or metamaterial-inspired three-dimensional magnetic EZ antennas, it has a huge impact on their directivity performance. Moreover, it is demonstrated that with both a metamaterial-inspired two-element array and a related Huygens dipole antenna, one can achieve broadside-radiating electrically small systems that have high directivities. Several common and original designs are used to highlight these issues and to emphasize why a fundamental figure of merit such as directivity should never be overlooked.

Original languageEnglish (US)
Article number7
JournalEPJ Applied Metamaterials
Volume4
DOIs
StatePublished - Jan 1 2017

Fingerprint

directivity
figure of merit
Metamaterials
antennas
Antennas
Microstrip antennas
patch antennas
Bandwidth
Dipole antennas
Antenna grounds
impedance
bandwidth
Radiators
dipole antennas
radiators
Radiation
occurrences
dipoles
radiation

Keywords

  • Directivity
  • Electrically small antennas
  • Huygens source
  • Metamaterial-inspired antennas
  • Patch antennas

ASJC Scopus subject areas

  • Mechanics of Materials
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

The directivity of a compact antenna : An unforgettable figure of merit. / Ziolkowski, Richard W.

In: EPJ Applied Metamaterials, Vol. 4, 7, 01.01.2017.

Research output: Contribution to journalArticle

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