Superdirective Magnetic Dipole Array as a First-Order Probe for Spherical Near-Field Antenna Measurements

Oleksiy S. Kim, Sergey Pivnenko, Olav Breinbjerg

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The theory as well as numerical and experimental results are presented for a superdirective array composed of closely spaced electrically small resonant magnetic dipole elements. The array operates on a metal ground plane and can exhibit a maximum directivity of 11.5 dBi, 15.2 dBi, and 17.8 dBi (including 3 dB due to the ground plane), for 2, 3, and 4 magnetic dipoles, respectively. The array is self-resonant and is directly excited by a 50-ohm coaxial cable through the ground plane. The array radiates essentially the $\vert\mu\vert=1$ spherical modes, which, despite a narrow bandwidth, makes it an excellent first-order probe for spherical near-field antenna measurements at low frequencies.
Original language English I E E E Transactions on Antennas and Propagation 60 10 0018-926X https://doi.org/10.1109/TAP.2012.2207363 Published - 2012

Keywords

• Electrically small antennas,
• First-order probe
• Magnetic dipole
• Spherical near-field antenna measurements
• Superdirectivity
• Supergain array