Pattern and Polarization Diversity Multi-Sector Annular Antenna for IoT
Applications
Abstract
This work proposes a small pattern and polarization diversity
multi-sector annular antenna with electrical size and profile of ka=1.2
and 0.018lambda, respectively. The antenna is planar and comprises
annular sectors that are fed using different ports to enable digital
beamforming techniques, with efficiency and gain of up to
78\% and 4.62 dBi, respectively. The cavity mode
analysis is used to describe the design concept and the antenna
diversity. The proposed method can produce different polarization states
(e.g. linearly and circularly polarized patterns), and pattern diversity
characteristics covering the elevation plane. Owing to its small
electrical size, low-profile and diversity properties, the solution
shows good promise to enable advanced radio applications like wireless
physical layer security in many emerging and size-constrained Internet
of Things (IoT) devices.