Frequency-tunable slot antenna using continuous electrowetting of liquid metal

Abstract

This paper presents a frequency-tunable slot an tenna which uses liquid metal to vary the electrical length of the radiating aperture. The liquid metal is driven by continuous elec trowetting (CEW), a process by which motion is induced in a liquid-metal droplet through the application of a potential gradi ent across an electrolytic carrier fluid. The process is both fully reversible and repeatable, and the low-voltage electrical driving mechanism allows for simpler integration into electronic archi tectures than more common hydraulic methods. We believe this is the first instance of CEW being used to create a tunable RF device.

Liquid-Metal-Based Reconfigurable Components for RF Front Ends

“…The antenna has a peak gain of 4.8 dBi and 4.1 dBi at its lowest and highest frequency states respectively. The TBW and gain are improved over similar liquid-metal slot antennas, which must use electrolyte filled channels for CEW ac-tuation [54]. These results are also comparable to frequency-reconfigurable slot antennas implemented with varactors [41], PIN diodes [43,44], and MEMS switches [45].…”

“…The use of electrolytic carrier fluids also allows for surface-tension-based actuation techniques [2,51,52] that are both low voltage and low power. However, aqueous solutions have unacceptably high loss tangents at microwave frequencies [53], and while careful channel design can minimize its impact on device performance [54], some degradation in gain and efficiency is unavoidable.…”

Frequency-Reconfigurable Dipole Antenna Using Liquid-Metal Pixels

“…Recent demonstrations in liquid-metal reconfigurable antennas include monopole [6,7], dipole [8], planar inverted F [9], Yagi-Uda [10][11][12], patch [13,14], and slot [15] antennas. Reconfigurability is achieved either by altering the physical dimensions of the radiating element with liquid metal or by configuring an associated liquid-metal parasitic element.…”

An Electrically Actuated Liquid-Metal Gain-Reconfigurable Antenna

“…Liquid metal, capable of assuming arbitrary shapes, offers the potential for the analog tunability of antenna parameters such as frequency, polarization, and gain over a wide range. Liquid metal has been used to implement the three conventional types of antenna reconfigurability [2]: frequency reconfigurability [6][7][8][9], polarization reconfigurability [10][11][12], and pattern reconfigurability [13][14][15]. This work explores gain reconfigurability, which not only can adjust communication range, but may also find uses in networks with interference.…”