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International audienceThis letter proposes an approach for the realization of three-dimensional flexible antennas based on the use of liquid metal and additive printing technologies. As a representative example, a miniaturized inverted-F antenna (IFA) operating at 885 MHz and suitable for wearable applications is designed, realized, and measured. The antenna sensitivity to the bending is strongly reduced, thanks to the proposed structure. The performance of the antenna in several bent configurations and in presence of the human body has been evaluated.},keywords={UHF antennas;liquid metals;rapid prototyping (industrial);three-dimensional printing;wearable antennas;3D flexible antenna realization;additive printing technology;antenna sensitivity;bent configurations;frequency 885 MHz;liquid metal;miniaturized inverted-F antenna;three-dimensional flexible antenna realization;wearable antenna;Additives;Antenna measurements;Antennas;Liquids;Metals;Phantoms;Three-dimensional displays;Additive technology;UHF;electro-textile;flexible antenna;liquid metal;wearable antenn

This study focuses on the design, simulation, and fabrication of a coplanar waveguide miniaturised wearable antenna that is fully implemented in textile materials and operable at 2.45/5.8 GHz for wireless local area network applications. This antenna is assumed to be placed near the human body, so that it needs to be miniaturised with excellent performances. To increase the performance of the short‐distance textile antenna and to control the specific absorption rate, an artificial magnetic conductor (AMC) is preferred as a reflector plane. The volume of the proposed antenna with AMC is 75 × 50 × 6 mm3, the simulation and measurement results are in good agreement and show that the antenna performances perform better results in comparison with the one reported so far in the literature while having a smaller volume. AMC significantly improves the performance of the antenna. The gains of the antenna are 8.2 and 9.95 dBi at 2.45 and 5.8 GHz, respectively (an increase of 3 dB compared with an antenna without AMC).

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A millimeter-wave (mmWave) textile antenna operating at 26 GHz band for 5G cellular networks is proposed in this paper. The electromagnetic characterization of the textile fabric used as substrate at the operating frequency was measured. The textile antenna was integrated with an electromagnetic bandgap (EBG) structure and placed on a polyester fabric substrate around the antenna. Results showed that the proposed EBG significantly improved the performance of the antenna. The gain and energy efficiency at 26 GHz were 8.65 dBi and 61%, respectively (an increase of 2.52 dB and 7% compared to a conventional antenna), and the specific absorption rate (SAR) was reduced by more than 69.9%. Good impedance matching of the fabricated antenna at the desired frequency was observed when it was bent and worn on the human body. The structure is simple, compact, and easy to manufacture. It may well be suitable for integration into applied clothing in various fields, especially for future IoT applications.

International audienceThis letter presents a reconfigurable antenna for mobile terminals with extended band coverage obtained by using a digitally tunable capacitor (DTC). The antenna structure is matched permanently over high frequency bands including DCS/PCS, UMTS, LTE 1800/2600, and 3.5-GHz bands. Concerning the sub-GHz bands, several reconfigurable states enable a full coverage of LTE 600/700 and GSM 850/900 standards, as well as expected spectrum reallocations for 5G communications. With dimensions of 40 ×10 ×6 mm3 for the antenna and 130 ×70 ×0.8 mm3 for the whole printed circuit board (PCB), this structure is compatible with any mobile terminal

With the development of modern wireless technologies and the miniaturization of antennas and electrical systems, the use of antennas on the human body for Wi‐Fi applications has become important. However, integrating the antenna near the body immediately raises the question about the protection of the body and the radiation effectiveness of the antenna. One solution that has recently attracted great attention is the use of high impedance surfaces (HIS), which is studied here for the antennas integrated on clothes. Indeed, the HIS greatly reduces the radiation back face of the antenna, thus reducing the value of the specific absorption rate in the presence of the body. In this article, we present a dual‐band antenna placed above an artificial magnetic conductor (AMC). The AMC used has the smallest dimensions and makes it possible to obtain the behavior of a perfect magnetic conductor at 2.45 and 5.8 GHz.

In this article, we present a low‐profile and low cost antenna for GPS (L1–L2–L5), Galileo (E5–E1–E2), and Glonass (G1–G2) standard. This antenna is a dual‐feed planar patch antenna with four slots to achieve dual‐band operation. The radiating element is fed by a wideband 90° quadrature hybrid coupler to obtain circular polarization on the both bands. The quadrature feeding is achieved using a three‐branch‐line hybrid coupler. The return loss bandwidth of the system (S11 ≤ −10 dB) is 22% in the lower band and 14% in the upper one. The axial ratio (AR) bandwidth in broadside direction (AR= 3 dB) is 20% in the lower band and 11.3% at the upper one. The antenna gain is 6 and 8.4 dBi in the normal direction at the central frequency of 1.23 and 1.6 GHz, respectively. The total dimensions of the antenna are 170 mm2 with a thickness of 7.524 mm. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2811–2814, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27175