Foldable and Stretchable Liquid Metal Planar Inverted Cone Antenna

• Published in: IEEE transactions on antennas and propagation 2009-12, Vol.57 (12), p.3765-3771
• Main Authors: Shi Cheng, Zhigang Wu, Hallbjorner, P., Hjort, K., Rydberg, A.
• Format: Article
• Language: English
• Subjects: Alloys; Antennas; Applied sciences; Bending; Conducting materials; Dielectric materials; Dielectrics; Engineering Science with specialization in Microwave Technology; Exact sciences and technology; Flexibility; Frequency; Information technology; Informationsteknik; Inorganic materials; Integrated circuit interconnections; Liquid alloy; Liquid metals; Noise levels; planar inverted cone antenna (PICA); polydimethylsiloxane (PDMS); Radiocommunications; Sheet materials; Signal processing; Signalbehandling; Silicon; stretchable electronics; Stretching; Substrates; TECHNOLOGY; TEKNIKVETENSKAP; Teknisk fysik med inriktning mot mikrovågsteknik; Telecommunications; Telecommunications and information theory; Ultra wideband antennas; Ultra wideband technology; Ultrawideband; ultrawideband (UWB)
• ISSN: 0018-926X; 1558-2221; 1558-2221
• DOI: 10.1109/TAP.2009.2024560

A mechanically flexible planar inverted cone antenna (PICA) for ultrawideband (UWB) applications is presented. It can be both folded and stretched significantly without permanent damage or loss of electrical functionality. The antenna is manufactured with a process in which conductors are realized by injecting room temperature liquid metal alloy into micro-structured channels in an elastic dielectric material. The elastic dielectric material together with the liquid metal enables bending with a very small radius, twisting, and stretching along any direction. Port impedance and radiation characteristics of the non-stretched and stretched antenna are studied in simulations and experiments. The presented antenna has a return loss better than 10 dB within 3-11 GHz and a radiation efficiency of > 70% over 3-10 GHz, also when stretched. Tests verify that stretching up to 40% is possible with maintained electrical performance. The presented antenna is useful for example for body-worn antennas and in applications in harsh environments where mechanical flexibility helps improve durability.