A Study on Application of Dielectric Resonator Antenna in Implantable Medical Devices

Worldwide, a large number of patients are benefited every year due to technological advancement in implantable medical devices (IMDs) such as in hyperthermia and bio-telemetry. The combination of sensors and antennas defined the quality of the implantable device. Antenna communities strive hard to fulfill the needs of the medical world by introducing new designs and concepts in this field. The purpose of this study is to identify major existing challenges and provide suitable solution of these challenges for implant applications. Present implant antennas have faced inferior performance due to high metallic losses and varied implant depth. The human body is a combination of dielectric materials, regardless of whether it is liquid (eg. water), gels or hard bones. In this study, first time a dielectric resonator antenna (DRA) resonating at 2.45 GHz, has been proposed as an implantable antenna with no metallic losses, varied implant depth performance and bio-compatibility. The implant DRA is placed on a bio-compatible polyvinyl chloride (PVC) substrate with a thickness of 0.5 mm. The rectangular DRA excited by a coplanar waveguide feed is proposed and its performance is compared with the help of four phantoms given in the literature. A detailed link design study was also undertaken in view of the different applications

Multiple input multiple output dielectric resonator antenna with circular polarized adaptability for 5G applications

In this paper, the concept of the circularly polarized agile, multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) structure for fifth generation (5G) new radio application in mobile terminal is presented. Two prototypes have been fabricated, namely one with cylindrical DRA (CDRA) referred as A1 and a second one with ring DRA (RDRA) named as A2. These practical realizations of dual-port MIMO antennas have been mounted on a Rogers 5870 substrate of octagonal shape with proper ground architecture. The proposed dual-port MIMO antennas have been excited with conformal probes and L-type feed network aiming to achieve circular polarization (CP). Measured impedance bandwidth of A1 and A2 are 21.2% (3.15-3.9 GHz) and 22.2% (3.12-3.9 GHz), respectively. Moreover, for both antennas low mutual coupling between ports with minimum isolation of dB over entire impedance bandwidth has been obtained by using triangular head slots in the ground plane. Measured axial ratio bandwidths in broadside direction are 5.66% (3.26-3.45 GHz) and 4.25% (3.45-3.6 GHz), respectively. Maximum gains are 7.3 and 7.2 dBi, in that order. MIMO antenna parameters such as envelope correction coefficient, diversity gain (DG), mean effective gain and total active reflection coefficient are also calculated to verify MIMO performance parameters. The proposed antennas also demonstrate CP agility with insertion of concentric cylindrical shells of different radii

Dual-band circularly polarized MIMO DRA for sub-6 GHz applications

In this article, a dual-band circularly polarized multiple-input-multiple-output (MIMO) dielectric resonator antenna (DRA) is proposed for 3.5 and 5.5 GHz bands, both being located under 6 GHz. Known as sub-6 (or as mid-band), they provide good coverage and capacity in the newly targeted fifth-generation (5G) systems. The proposed structure consists of two ring DRAs (RDRAs) etched on a 0.8 mm thick RT Duroid substrate. Measured impedance bandwidths in broadside direction are 3.1-3.75 GHz (19%) and 5.3-5.6 GHz (9.4%) and circular polarization (CP) bandwidths are 3.425-3.6 GHz (5%) and 5.45-5.55 GHz (2%), respectively. CP is achieved by exciting HE modes using two probes placed orthogonaly to each other, that is, at an azimuthal angular distance of 90∘. Varying the lengths of the probe allows achieving the necessary time-phase quadrature between modes. Comparison between recent multiband circularly polarized MIMO DRAs and proposed prototype has revealed that CP bandwidth in both bands is one of the highlighting advantages of the present configuration

Dielectric Resonator Antennas: Applications and developments in multiple-input, multiple-output technology

This article presents a comprehensive review of multiple-input, multiple-output (MIMO) dielectric resonator antennas (DRAs) that have evolved in the past decade. In addition to the major challenges faced during designing an MIMO DRA, this article also discusses research gaps that must be filled in the future. Exploring the advantages of DRAs, numerous novel designs have been proposed in the last few years

Olfactory perireceptor and receptor events in moths: a kinetic model revised

Modelling reveals that within about 3 ms after entering the sensillum lymph, 17% of total pheromone is enzymatically degraded while 83% is bound to the pheromone-binding protein (PBP) and thereby largely protected from enzymatic degradation. The latter proceeds within minutes, 20,000-fold more slowly than with the free pheromone. In vivo the complex pheromone–PBP interacts with the receptor molecule. At weak stimulation the half-life of the active complex is 0.8 s due to the postulated pheromone deactivation. Most likely this process is enzymatically catalysed; it changes the PBP into a scavenger form, possibly by interference with the C-terminus. The indirectly determined PBP concentration (3.8 mM) is close to direct measurements. The calculated density of receptor molecules within the plasma membrane of the receptor neuron reaches up to 6,000 units per μm2. This is compared with the estimated densities of the sensory-neuron membrane protein and of ion channels. The EC50 of the model pheromone–PBP complex interacting with the receptor molecules is 6.8 μM, as compared with the EC50 = 1.5 μM of bombykol recently determined using heterologous expression. A possible mechanism widening the range of stimulus intensities covered by the dose–response curve of the receptor-potential is proposed

CURATION AND MANAGEMENT OF CULTURAL HERITAGE THROUGH LIBRARIES

Libraries, museums and archives hold valuable collections in a variety of media, presenting a vast body of knowledge rooted in the history of human civilisation. These form the repository of the wisdom of great works by thinkers of past and the present. The holdings of these institutions are priceless heritage of the mankind as they preserve documents, ideas, and the oral and written records. To value the cultural heritage and to care for it as a treasure bequeathed to us by our ancestors is the major responsibility of libraries. The past records constitute a natural resource and are indispensable to the present generation as well as to the generations to come. Libraries preserve the documentary heritage resources for which they are primarily responsible. Any loss of such materials is simply irreplaceable. Therefore, preserving this intellectual, cultural heritage becomes not only the academic commitment but also the moral responsibility of the librarians/information scientists, who are in charge of these repositories. The high quality of the papers and the discussion represent the thinking and experience of experts in their particular fields. The contributed papers also relate to the methodology used in libraries in Asia to provide access to manuscripts and cultural heritage. The volume discusses best practices in Knowledge preservation and how to collaborate and preserve the culture. The book also deals with manuscript and archives issues in the digital era. The approach of this book is concise, comprehensively, covering all major aspects of preservation and conservation through libraries. The readership of the book is not just limited to library and information science professionals, but also for those involved in conservation, preservation, restoration or other related disciplines. The book will be useful for librarians, archivists and conservators. We thank the Sunan Kalijaga University, Special Libraries Association- Asian Chapter for their trust and their constant support, all the contributors for their submissions, the members of the Local and International Committee for their reviewing effort for making this publication possible

Printed Antennas for 5G Networks

The book provides a comprehensive overview of antennas for 5G technology, such as MIMO, multiband antennas, Magneto-Electric Dipole Antenna and PIFA Antenna for 5G networks, phased array antennas for 5G access, beam-forming and beam-steering issues, 5G antennas for specific applications (smartphone, cognitive radio) and advance antenna concept and materials for 5G. The book also covers ooptimizations methods for passive and active devices in mm-Wave 5G networks. It explores topics which influence the design and characterization of antennas such as data rates, high isolation, pattern and spatial diversity, making 5G antennas more suitable for a multipath environment. The book represents a learning tool for researchers in the field, and enables engineers, designers and manufacturers to identify key design challenges of antennas for 5G networks, and characterize novel antennas for 5G networks