Frequency- and Pattern-Reconfigurable Antenna Enabled by a Liquid Metal-Based Common-Mode and Differential-Mode Feeding Structure

This paper presents a frequency and radiation pattern reconfigurable antenna utilizing liquid metal to achieve common-mode and differential-mode feeding structure. The proposed antenna consists of three components: a printed symmetric dipole serving as the radiation element, a director, and a microstrip-based common-mode and differential-mode feeding structure. The innovative feeding structure employs liquid metal microfluidic technology to achieve dynamic mode reconfiguration. Specifically, reconfigurable differential/common mode feeding is realized by injecting liquid metal into two precisely designed microfluidic channels fabricated on a polytetrafluoroethylene (PTFE) substrate. The antenna generates a “ 8 ” radiation pattern with an operational bandwidth spanning from 1.11 GHz to 1.18 GHz. In the second mode, the antenna functions as a conventional Yagi-Uda antenna with an impedance bandwidth covering 2.03 GHz to 2.43 GHz. To enhance performance characteristics, the director is incorporated to broaden the operational bandwidth in the differential mode. According to CST Microwave Studio^® simulation results, the antenna achieves a maximum gain of 6.27 dBi.