Microfluidically Reconfigured Wideband Frequency-Tunable Liquid-Metal Monopole Antenna

Abstract

A microfluidically reconfigured wideband frequency-tunable liquid-metal monopole antenna is presented. The antenna operation relies on continuous moving of the liquid-metal volume over the capacitively coupled microstrip line feed network with a micropump unit. To maximize the capacitive coupling at the feed point, the antenna is realized by bonding microfluidic channel molds prepared in polydimethylsiloxane (PDMS) polymer with 1-mil-thick liquid crystal polymer (LCP) substrate. The concept is demonstrated through the design and experimentation of a 4:1 frequency-tunable monopole antenna that operates from 1.29 to 5.17 GHz. The presented monopole antenna can also be utilized as an element to form wideband frequency-tunable high-gain antenna apertures without necessitating any additional micropump units. This is accomplished by resorting to strategically meandered or interconnected microfluidic channels. This concept is demonstrated through the design and experimentation of a 4 × 1 microfluidically controlled monopole array capable of providing 2:1 frequency tuning range from 2.5 to 5 GHz.