Abstract
To meet the demands of maritime transportation on ships, including satellite positioning, wireless communication, and radio frequency identification (RFID) for cargo handling management, a function reconfigurable antenna based on liquid metal is proposed in this paper. The antenna is composed of 3-D-printed hollow cavities, a two-step impedance feeding sheet, and two feeding probes. The 3-D-printed hollow cavities contain a big hollow helix cavity, a hollow cone loaded cylinder cavity, four hollow cylinder cavities, and four small hollow helix cavities. By filling the liquid metal into different hollow cavities, reconfigurable functions are generated, including right-handed circular polarization (RHCP), omnidirectional linear polarization (O-LP), pattern reconfigurable circular polarization, and omnidirectional left-handed circular polarization (O-LHCP). To illustrate this, a prototype is fabricated using 3-D-printed photopolymer resin and etching technology. The measurement results agree well with the simulated ones in terms of return loss, radiation pattern, gain, and axial ratio (AR). For the five reconfigurable states, the measured relative bandwidths for |S11| < −10 dB are 44.7%, 41.7%, 30.4%, 28.1%, and 10.8%, respectively, which covers the bands of a global navigation satellite system (GNSS), wireless communication system, and RFID communication system. Attributing to the advantages of its compact structure, flexible conversion, and good performance, the proposed antenna is a good candidate for maritime transportation applications.
Highlights
In the field of maritime transportation, ships must be capable of satellite positioning, wireless communication, and radio frequency identification (RFID) for cargo handling management, which leads to the installation of too many antennas on the ship, causing serious electromagnetic interference
The measured bandwidth is in the range of 1.06–1.67 GHz, covering the global navigation satellite system (GNSS) frequency band
The liquid metal may adhere to the cavities during repeat injection in practice, which may affect the performance of the proposed liquid metal antenna
Summary
In the field of maritime transportation, ships must be capable of satellite positioning, wireless communication, and radio frequency identification (RFID) for cargo handling management, which leads to the installation of too many antennas on the ship, causing serious electromagnetic interference.In addition, ship antennas with low radar cross section (RCS) are always required in some applications, such as the military field. In the field of maritime transportation, ships must be capable of satellite positioning, wireless communication, and radio frequency identification (RFID) for cargo handling management, which leads to the installation of too many antennas on the ship, causing serious electromagnetic interference. Aperture sharing techniques have often been used for the integration of antennas [2,3,4]. Aside from shared-aperture antennas, reconfigurable antennas are another solution to this electromagnetic interference. Since different functions of the reconfigurable antennas are realized through switching, the interference can be eliminated. Reconfigurable antennas have the advantages of enhancing the channel capacity [5], reducing multipath interference [6], mitigating wireless propagation channels [7], and expanding radiation coverage [8]. Microwave pin switches [9,10], RF MEMS switches [11, 12], and varactor diodes [13,14] are applied to realize reconfigurability, including frequency, polarization, Electronics 2020, 9, 873; doi:10.3390/electronics9050873 www.mdpi.com/journal/electronics
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
