Soft and Flexible Antennas on Permittivity Adjustable PDMS Substrates

This work presents novel techniques for producing substrates for flexible antennas. The technique we propose is based on the use of an already existing and widely used substrate material Polydimethylsiloxane (PDMS), where the dielectric properties of the substrate are adjusted by loading the PDMS with low or high permittivity inclusions. The low adhesion characteristics of PDMS are overcome by immersing the conducting parts of the antenna inside the substrate, at the same time sealing the antenna against the influence of dust, or water. A patch antenna prototype is realized and characterized. The built antenna is soft and flexible and it shows good radiation characteristics in terms of input matching and total gain. Measurements are in a good compliance with the simulation results

Performance of UHF W-BAN antennas in a real environment scenario

This work presents performance of robust wearable antennas intended to operate in Wireless Body Area Networks (W-BAN) in UHF, TETRAPOL communication band, 380-400 MHz. We propose a Planar Inverted F Antenna (PIFA) as reliable antenna type for UHF W-BAN applications. In order to satisfy the robustness requirements of the UHF band, both from communication and mechanical aspect, a new technology for building these antennas was proposed. The antennas are built out of flexible conductive sheets encapsulated inside a silicone based elastomer, Polydimethylsiloxane (PDMS). The proposed antennas are resistive to washing, bending and perforating. From the communication point of view, opting for a PIFA antenna type we solve the problem of coupling to the wearer and thus improve the overall communication performance of the antenna. Several different tests and comparisons were performed in order to check the stability of the proposed antennas when they are placed on the wearer or left in a common everyday environ- ment, on the ground, table etc. S11 deviations are observed and compared with the commercially available wearable antennas. As a final check, the antennas were tested in the frame of an existing UHF TETRAPOL communication system. All the measurements were performed in a real university campus scenario, showing reliable and good performance of the proposed PIFA antennas. © 2014 IEEE

Design and analysis of planar UHF wearable antenna

Slotted PIFA on the textile substrate suitable for body-centric applications in the UHF band is proposed. The influence of slot in the ground plane on the antenna parameters is theoretically investigated using simplified model of human body. © 2012 IEEE

Compact UWB antennas for Wireless Body Area Networks (W-BANs)

A major issue in Wireless Body Area Networks (W-BAN) is the reliability of the transmission in all conditions, thus in all locations and positions of the wearer. One way to achieve this is to design communication systems as independent as possible to the presence of the wearer, and to use multiple antennas (diversity, MIMO) to overcome fading. Polarization diversity is a good candidate for W-BAN, as it allows for the design of compact antennas having potentially a good diversity gain. Ultra Wide Band (UWB) has proved to be good candidate for W-BAN, in the case where high data rates over short ranges are targeted. In order to achieve polarization diversity, both UWB antennas having a polarization orthogonal and parallel to the surface of the wearer are required. While the latter are easy to design, it is not obvious design low profile UWB antennas with a vertical polarization. Moreover and for both cases, the design of antenna elements coupling as little as possible to each other or to the wearer is a key issue to the final quality of the system. In this contribution, we present a low profile UWB antenna having a polarization orthogonal to the wearer, which inherently minimizes the coupling to the body. © 2014 IEEE

Design considerations for wearable antennas

International audienceWith the development of generalized connectivity and the increased use of Body Area Networks, wearable antennas have become ubiquitous in the last decade. Their design presents a challenge, as they per definition are located at the interface between free space and an environment which is intrinsically lossy and hostile to the efficient radiation of electromagnetic waves. In this contribution, we propose a theoretical analysis of different canonical sources placed on biological tissues. Based on the insight gained, several simple design rules will be proposed and illustrated on a practical antenna design. © 2016 IEEE