Configurable Defected Ground Structures for Low Profile Antenna
Performance Enhancement
Abstract
Versatile configurable defected ground structures
(CDGSs) for enhancing the performance of low profile antennas are
introduced. It is shown that CDGS can significantly reduce mutual
coupling (MC) between multiple antennas and suppress cross-polarization
(XP) and enhance circular polarization (CP) excitation in single port
low profile antennas for example. The key idea of CDGS is to construct
defected ground structures (DGSs) from a grid of slots, which can be
either opened or shorted with hardwires, so that they can be configured
and optimized to enhance desired antenna performance characteristics.
The
importance and versatility of the CDGS approach is that it
overcomes the issue of having to design bespoke DGS for each individual
antenna design. Three design examples are provided to demonstrate the
versatility of CDGSs for MC reduction, XP suppression and CP excitation.
Experimental results demonstrate that MC can be reduced by up to 43 dB,
XP can be suppressed by 15 dB and CP can be excited with 78 MHz (2.2%)
3-dB axial ratio (AR) bandwidth. The compactness and ease of fabrication
also make the CDGS well suited to compact low profile internet of things
(IoT) and wireless communication applications.