Localizing Radiation for Radiation Pattern Manipulation of Monopole Antennas With Finite-Sized Ground Planes

The radiation patterns of antennas, formed by monopoles and finite-sized ground planes, significantly impact the coverage and quality of wireless communications. This paper proposes a concept to manipulate the radiation patterns of the antennas by forming new ground plane's boundaries to effectively localize the radiation. The concept is proposed based on the analysis of radiation pattern distortion. Two design methods are presented to implement the concept in two antenna systems: a two-antenna system for WLAN with a rectangular ground plane and a four-antenna system for WLAN with a square ground plane. In both cases, the asymmetrical configurations severely distort the radiation patterns of the antennas. By integrating metasurfaces and metarings, the distorted radiations are significantly mitigated by localizing the radiation to a symmetrical region. The techniques based on the proposed concept also show enhanced port isolation.