Design of pattern-reconfigurable circularly polarized unidirectional antenna based on quasi-radiator for ISM applications

Philip Arthur; Mubarak Sani Ellis; Abdul-Rahman Ahmed; Jerry John Kponyo

doi:10.1016/j.heliyon.2022.e11721

Design of pattern-reconfigurable circularly polarized unidirectional antenna based on quasi-radiator for ISM applications

Heliyon. 2022 Nov 18;8(11):e11721. doi: 10.1016/j.heliyon.2022.e11721. eCollection 2022 Nov.

Authors

Philip Arthur¹, Mubarak Sani Ellis¹, Abdul-Rahman Ahmed¹, Jerry John Kponyo¹

Affiliation

¹ Department of Telecommunication Engineering, Kwame Nkrumah University of Science and Technology, Kumasi-Ghana.

Abstract

A pattern-reconfigurable circularly polarized antenna for 2.45 GHz industrial, scientific, and medical (ISM) band applications is designed in this work. The proposed antenna consists of a slotted-stepped monopole connected to a rectangular ground plane via a shorting side-stub. This converts the omnidirectional radiation pattern of the antenna into stable unidirectional radiation. To dynamically steer the realized pattern, two switchable RF PIN diodes are jointly incorporated into the side-stubs to achieve symmetrical radiations in specific operating modes. In this way, the radiation patterns can be simultaneously tuned in the $\pm y$ directions by the simple switching of the PIN diodes ON and OFF. The fabricated prototype achieves an $S_{11}$ smaller than -10dB within the 3dB axial ratio (AR) bandwidth with stable far-field patterns. The antenna maintains a low-profile and compact size of ${0.055 λ}_{0}^{2}$ which makes it suitable for body-centric wireless communication (BWC) and personal wireless area networks.

Keywords: Circular polarization; PIN diode; Pattern-reconfigurable; Unidirectional radiation.