Abu Bakar Habshah, Abd Rahim Rosemizi, Soh Ping Jack, Akkaraekthalin Prayoot
Department of Electrical Engineering, Politeknik Sultan Abdul Halim Muadzam Shah, Jitra 06000, Kedah, Malaysia.
Faculty of Electronic Engineering Technology, Pauh Putra Campus, Universiti Malaysia Perlis, Pauh 02600, Perlis, Malaysia.
Sensors (Basel). 2021 Jan 26;21(3):827. doi: 10.3390/s21030827.
Advances in reconfigurable liquid-based reconfigurable antennas are enabling new possibilities to fulfil the requirements of more advanced wireless communication systems. In this review, a comparative analysis of various state-of-the-art concepts and techniques for designing reconfigurable antennas using liquid is presented. First, the electrical properties of different liquids at room temperature commonly used in reconfigurable antennas are identified. This is followed by a discussion of various liquid actuation techniques in enabling high frequency reconfigurability. Next, the liquid-based reconfigurable antennas in literature used to achieve the different types of reconfiguration will be critically reviewed. These include frequency-, polarization-, radiation pattern-, and compound reconfigurability. The current concepts of liquid-based reconfigurable antennas can be classified broadly into three basic approaches: altering the physical (and electrical) dimensions of antennas using liquid; applying liquid-based sections as reactive loads; implementation of liquids as dielectric resonators. Each concept and their design approaches will be examined, outlining their benefits, limitations, and possible future improvements.
可重构液体基可重构天线的进展为满足更先进无线通信系统的要求带来了新的可能性。在本综述中，对使用液体设计可重构天线的各种最新概念和技术进行了比较分析。首先，确定了可重构天线中常用的不同液体在室温下的电学特性。接下来讨论了实现高频可重构性的各种液体驱动技术。然后，将对文献中用于实现不同类型重构的基于液体的可重构天线进行批判性综述。这些类型包括频率、极化、辐射方向图和复合可重构性。当前基于液体的可重构天线概念大致可分为三种基本方法：使用液体改变天线的物理（和电学）尺寸；将基于液体的部分用作电抗负载；将液体用作介质谐振器。将研究每个概念及其设计方法，概述其优点、局限性以及未来可能的改进。
