Liquid Metal Bandwidth-Reconfigurable Antenna

Abstract

This paper shows how slugs of liquid metal can be used to connect/disconnect large areas of metalisation and achieve radiation performance not possible by using conventional switches. The proposed antenna can switch its operating bandwidth between ultra-wideband and narrowband by connecting/disconnecting the ground plane for the feedline from that of the radiator. This could be achieved by using conventional semiconductor switches. However, such switches provide point-like contacts. Consequently, there are gaps in electrical contact between the switches. Surface currents, flowing around these gaps, lead to significant back radiation. In this paper, slugs of liquid metal are used to completely fill the gaps. This significantly reduces the back radiation, increases the boresight gain, and produces a pattern identical to that of a conventional microstrip patch antenna. Specifically, the realised gain and total efficiency are increased by 2 dBi and 24%, respectively. The antenna has potential applications in wireless systems employing Cognitive Radio and Spectrum Aggregation.

Recent Advances in Deformable Circuit Components with Liquid Metal

“…Alqurashi et al. [ 124 ] proposed a liquid metal reconfigurable antenna capable of switching the frequency operating bandwidth between ultrawideband and narrowband. Switching was achieved by altering the configuration of the ground plane with respect to the radiating element by using slugs of liquid metal for the connection and disconnection of large metallization areas.…”

A Gravity-Triggered Liquid Metal Patch Antenna with Reconfigurable Frequency

“…The existing techniques of deforming and reconstructing liquid metal can be divided into mechanical and electric actuating methods. Mechanical actuating includes, e.g., methods such as pressurization by a syringe [ 11 , 12 , 13 , 14 ] or a pump [ 15 , 16 , 17 ], thermal expansion [ 18 ], gravity [ 19 , 20 ], or external forces [ 21 , 22 , 23 ]. Instances of electric actuating include electrochemistry [ 24 , 25 ] and capillary electrowetting [ 26 , 27 ].…”

A pattern‐ and frequency‐reconfigurable antenna using liquid metal

“…To the authors' knowledge, most of the existing liquid metal based designs focus on single reconfiguration modality, [15][16][17] but few designs of compound type have been reported. Reference 18 presents a liquid metal crossed dipole antenna created by using electrochemically controlled capillarity (ECC) actuation method.…”