Metastructure-Enabled Radiation Pattern Unroundness Improvement for Antennas in Complex Electromagnetic Environments
Authors:
Zhi Ning Chen, Bo Zhang, Huiwen Sheng
Abstract:
Radiation pattern roundness is critical for achieving reliable and uniform coverage in wireless communication
systems. However, antennas operating in complex environments—such as those mounted off-center on finite
platforms or enclosed within dielectric covers—often suffer from pattern distortion due to asymmetric boundary
conditions and unwanted guided waves. This paper investigates metastructure-based solutions to mitigate
radiation pattern unroundness for both vertically and horizontally polarized antennas. For vertically
polarized monopoles, impedance surfaces and Henge-like metarings are designed to suppress edge-diffracted
currents and enhance omnidirectionality. For horizontally polarized dipole-based antennas, a uniaxial
anisotropic meta-cover is proposed to suppress guided wave propagation within dielectric enclosures. The
proposed metastructures significantly improve radiation pattern unroundness to lower than 1.9 dB and enhance
coverage efficiency up to 84.7%. These methods provide a viable pathway for improving antenna performance in
confined or asymmetrical settings, supporting the development of high-capacity, robust wireless networks.
