Papers by William Whittow
Embroidered Frequency Selective Surfaces on textiles for wearable applications
2013 Loughborough Antennas & Propagation Conference (LAPC), 2013
ABSTRACT An assessment of a Frequency Selective Surface (FSS) for wearable applications is presen... more ABSTRACT An assessment of a Frequency Selective Surface (FSS) for wearable applications is presented. The textile FSS array was created on 0.8 mm thick felt material using a fast and cost effective embroidery technique with conducting threads. This operates at 2 GHz with transmission coefficient lower than 10 dB. The FSS structure was also modelled using commercial simulation tools. This work is towards low-loss textile FSS structures for wearable applications.
2012 6th European Conference on Antennas and Propagation (EUCAP), 2012
This paper examines the advantages and challenges of creating microwave patch antennas using cond... more This paper examines the advantages and challenges of creating microwave patch antennas using conducting threads. The antennas are produced using automated embroidery machinery that could be easily scaled up to mass manufacture. Textile patch antennas are designed that resonate between 2 and 2.7GHz depending on the substrate. Different stitch directions and compositions were considered. Measured gain and efficiency results are included in this paper.
Electronics Letters, 2013
A new approach to interfacing fabric based wireless systems to traditional electronics circuitry ... more A new approach to interfacing fabric based wireless systems to traditional electronics circuitry is presented. Measurements show possible insertion losses of the connector to be < 1 dB up to frequencies of about 4 GHz when electroplating has been used to increase the hook and loop conductivities. This reported work points towards an interconnection system that is flexible and will allow the removal and replacement of conventional electronics connected to textile based systems.
Embroidered Frequency Selective Surfaces on textiles for wearable applications
2013 Loughborough Antennas & Propagation Conference (LAPC), 2013
ABSTRACT An assessment of a Frequency Selective Surface (FSS) for wearable applications is presen... more ABSTRACT An assessment of a Frequency Selective Surface (FSS) for wearable applications is presented. The textile FSS array was created on 0.8 mm thick felt material using a fast and cost effective embroidery technique with conducting threads. This operates at 2 GHz with transmission coefficient lower than 10 dB. The FSS structure was also modelled using commercial simulation tools. This work is towards low-loss textile FSS structures for wearable applications.
IET Microwaves, Antennas & Propagation, 2013
Simulated and measured microstrip patch antennas produced using embroidery techniques have been p... more Simulated and measured microstrip patch antennas produced using embroidery techniques have been presented. The antennas use a standard microwave substrate material. The effect of stitch direction and stitch density is described and a clear requirement to understand how the currents flow in an antenna, so that the stitch direction can be correctly chosen is shown. Two different simulation approaches for these antennas are discussed and one is linked to measurement results, pointing to a simplified model for simulating embroidered patch antennas.
2011 Loughborough Antennas & Propagation Conference, 2011
This paper investigates the concept of using conductive threads for fabricating electronics inclu... more This paper investigates the concept of using conductive threads for fabricating electronics including antennas at microwave frequencies. A number of commercial conductive threads have been considered. Digital embroidery has been used to create samples with different stitch types. This paper will provide a wide range of practical advice about fabricating samples using such materials. The threads have been examined by assessing their DC resistances at rest and while under physical strain and also the RF performance of transmission lines. The results show there is a wide range in performance between different conductive threads.
2012 Loughborough Antennas & Propagation Conference (LAPC), 2012
This paper is focused on using conductive threads to design flexible antennas with textile featur... more This paper is focused on using conductive threads to design flexible antennas with textile features which means antennas can be embroidered directly into normal clothes. The fabric microstrip antennas are made from commercial conductive threads. The gain and efficiency of fabric antennas have been measured and compared with a reference copper patch antenna. Effects from different stitches geometries within the fabric antenna are discussed. The results demonstrate the feasibility of wearable antennas.
Fully fabric knitted antennas for wearable electronics
2013 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2013
ABSTRACT form only given. The worldwide wearable technology market is expected to exceed $6B by 2... more ABSTRACT form only given. The worldwide wearable technology market is expected to exceed $6B by 2016 and wearable antennas will be used by the emergency services, fashion designers, military, athletes and patients. Exploring different methods of fabricating antennas is important especially as user comfort and aesthetics are key considerations in ensuring mainstream acceptance. Previously the authors have examined embroidered antennas using highly conductive threads [Chauraya et al. EuCAP 2012]. Please see this paper for a detailed literature review of wearable antennas. In this paper, we examine knitting as a technique of fabricating antennas. These antennas were fully fabric with a knitted ground plane, a knitted substrate and a knitted patch element. They were fabricated using industrial knitting machinery and hence could potentially be scaled up to mass-manufacture. Four different versions were considered (all had a knitted ground plane and substrate): i) a conducting coated nylon fabric (Nora Dell); ii) a knitted patch with a high fiber density (Sample 1); iii) a knitted patch with a medium fiber density (Sample 2) and iv) a knitted patch with a coarse fiber density (Sample 3). The resulting antennas were extremely flexible and soft to the touch. The return loss results are shown in the figure. All the antennas were fed with a probe feed positioned the same distance from the edge of the patch - the magnitude of the return loss could be improved by finding the optimal feeding point. The S11 and associated bandwidth results of the antennas suggests that the Nora Dell antenna exhibits the smallest losses. The results also indicate that the losses of the knitted antennas improve as the knitted patches became denser. The presentation will include measured radiation patterns, efficiency results and an in-depth analysis of the strengths and weaknesses of this manufacturing technique.
Textile manufacturing techniques in RF devices
2014 Loughborough Antennas and Propagation Conference (LAPC), 2014
Simulation methodology to model the behavior of wearable antennas composed of embroidered conductive threads
A Study of Head Worn Jewellery, Mobile Phone RF Energy and the Effect of Differing Tissue Types on Rates of Absorption
Experimental Verification of a Modified Specific Anthropomorphic Mannequin (SAM) Head Used for SAR Measurements
The SAR Effects of Popular Jewellery on the Human Head
Changes in specific absorption rate in the head due to metallic gap loops and a simulated mobile phone source in a study of the effects of jewellery
On the Question of Whether to Model or Measure the Levels of RF Energy from Mobile Phones into the Head
A Study of the Effects of Metallic Pins on Sar using a Specific Anthropomorphic Mannequin (SAM) Head Phantom
Composite materials for microwave devices using additive manufacturing
Electronics Letters, 2016
Higher-mode Textile Patch Antenna with Embroidered Vias for On-body Communication
IET Microwaves, Antennas & Propagation, 2016
Novel additive manufactured synthetic dielectric substrates
2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2015
Substrates with non-uniform 3D geometries for miniaturization of microstrip patch antennas and aesthetic design
2014 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2014
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Papers by William Whittow