Asymmetric liquid flow control polarization reconfigurable cylindrical dielectric resonator antenna for wireless communications

Abstract

This paper introduces a cylindrical dielectric resonator antenna (CDRA) with three reconfigurable polarization cases using liquid flow control. The CDRA volume has two pairs of drilling cylindrical holes with unsymmetrical radii and positions from the CDRA center along the two orthogonal diagonals. The liquid is flowing alternately in one‐cylindrical hole pair and is extracted from the other for polarization control. The two hole pairs radii and locations are optimized for minimum axial ratio (AR) of 1.5 dB at 5.8 GHz. Four polarization cases are achieved for left‐hand circular (LHCP), right‐hand circular (RHCP), and linear polarization (LP). The insertion of air holes pair in case (A) and case (B) widens the bandwidth (BW) to 1.28 GHz with high gain of 6.6 dBi in θ = 0, ϕ = 0 direction. The sequential rotation array arrangements are employed for circular polarization BW enhancement. Three arrangements are investigated. To improve the AR BW arrangement (III) introduces an improvement of 2 GHz compared with 60 MHz for the single CDRA element with a peak gain of 13.3 dBi.