Radially Polarized Annular-Slot Leaky-Wave Antenna for Three-Dimensional Near-Field Microwave Focusing Articles uri icon

publication date

  • March 2014

start page

  • 583

end page

  • 586


  • 13

International Standard Serial Number (ISSN)

  • 1536-1225

Electronic International Standard Serial Number (EISSN)

  • 1548-5757


  • Microwave three-dimensional near-field focusing with radial polarization using a holographic annular-slot antenna is demonstrated in this letter. This radial polarization can generate axially polarized focused fields in the near-field regime, which complements the more conventional synthesis of transversally polarized near-field focusing patterns. Moreover, it is shown that more symmetrical focal region is obtained thanks to the radial polarization for similar Fresnel number N and operation frequency. The theory is demonstrated with experiments for a design operating at 10 GHz, with aperture diameter D = 6 lambda and a Fresnel number N = 4.


  • focal depth; leaky-wave antennas; three-dimensional near-field focused microwave antennas; microstrip array; design; lenses