233 research outputs found
Tattoo Antenna Temporary Transfers Operating On-Skin (TATTOOS)
This paper discusses the development of RFID logo antennas based on the logos of Loughborough University and the University of Kent which can be tattooed directly onto the skin’s surface. Hence, this paper uses aesthetic principles to create functional wearable technology. Simulations of possible designs for the tattoo tags have been carried out to optimize their performance. Prototypes of the tag designs were fabricated and read range measurements with the transfer tattoos on a volunteers arm were carried out to test the performance. Measured Read ranges of approximately 0.5 m have been achieved with the antenna 10 µm from the body
Modifying conventional microwave antenna designs using fine scale structures and nanomaterials
This paper investigates the possibility of designing and fabricating microwave antennas using metallic nanomaterials. Specifically, we will consider modifying the structure of conventional designs including dipoles, loops and apertures. FDTD simulations are used to examine these modified structures. Due to the prohibitive computational requirements of modelling nanoscale objects on a millimetre scale, the structures are approximated using larger scale objects. However, cell sizes down to 2¿m have been considered. The results show that the frequency can be decreased. However, typically the bandwidth decreases
Nano-metamaterial antennas at microwave frequencies
This paper examines the possibility of creating novel microwave frequency antennas by suitably arranging
metallic / dielectric nanoparticles. Simulation results show that the antenna must be composed of ≥ 99% metal (<1 % gaps)
Microwave aperture antennas using nanomaterials
In this paper, computer simulations are used to
investigate the concept of designing microwave aperture
antennas, potentially fabricated using metallic nanomaterials.
Nanomaterials are considered as they facilitate fabrication and
electromagnetic advantages. Aperture radiating structures have
been excited by a plane wave in a microstrip line. The aperture
was modified with the addition of fine scale structures; vertical
strips shorter than the height of the aperture. These initial
simulation results have shown that these fine structures inside
the aperture can decrease the resonance frequency at the expense
of the bandwidth
Antenna performance on quasi synthetic media
While we seem to be experiencing a material evolution by applying unique properties of metamaterials,
such as negative constitutive parameters and to some extent cloaking phenomena, not much attention has been paid in
the practical suitability of synthetic materials towards antenna designs. The antenna designer is often faced with a
judicious choice of:- complexity in the conducting/radiating shape, substrate and radome parameters, cost as well as
ever increasing environmental effects both in the construction but also in the disposal of the antenna as part of a
recycling process. This paper will outline some of the hypotheses and processes that underpin our terminology of quasi
synthetic media and will proceed to illustrate how one can obtain a variety of dielectric (and magnetic) effective
contrasts from 3-D structures containing either dielectric or conducting micro particles. Some representative patch
designs are considered to indicate how one could replace cumbersome conventional design and manufacturing
processes by using nanotechnology and additive manufacturing
Review of artificial dielectrics containing small scale inclusions
This paper reviews some of the latest advances in the field of artificial dielectrics. The dielectric properties (permittivity and losses) can be designed and synthesized by placing small scale inclusions in a host medium. This work will create many new opportunities for antenna designers and will also lead to applications in transformation optics. This paper highlights the progress made in understanding the analytical, practical and measurement aspects of this work
Additively manufactured artificial materials with metallic meta-atoms
The paper presents the analysis and fabrication of artificial materials with metallic cuboid inclusions (termed here as meta-atoms) in a dielectric host material. These synthetic materials or metamaterials have been additively manufactured with a fused deposition modelling (FDM) 3D-printer. The effective permittivity and permeability have been numerically analyzed using the Maxwell-Garnett and Lewin’s approximation. Simulations and measurements have shown good agreement with analytical calculations. The anisotropy of the heterogeneous mixture due to the orientation of the meta-atoms has been demonstrated. The effective permittivity has been increased by the presence of the meta-atoms, which has the potential of producing 3D-printing metamaterials with tailored electromagnetic properties
Designing microwave patch antennas using heterogeneous substrates
This paper introduces the concept of designing
microwave patch antennas by creating synthetic heterogeneous
substrates with small scale inclusions. These inclusions embedded
in a host dielectric can be used to control the dielectric properties
and create bespoke effective permittivity values. Heterogeneous
patch antennas at 2.4GHz are simulated in this paper. By
deliberately mapping the permittivity values to the electric fields,
the antenna behavior can be controlled and a dual band
frequency was introduced. The local regions with micro-scale
inclusions showed good agreement with a homogeneous substrate
section with the same predicted permittivity. These
heterogeneous substrates can be potentially created using
nanomaterials
Artificially engineered capacitors for discrete high-frequency electronic circuitry
The concept of the artificially engineered capacitor (AEC) is presented as a 3D printable 3D capacitive component for the use in discrete RF/microwave electronic circuitry. The intention of the AEC concept is a highly customizable 3D printable component whose capacitance value is stable over a wider frequency band when compared to commercial alternatives. AECs can be viewed as impedance structures with predominantly capacitive characteristics. Both series and shunt AEC configurations are considered with simulation and measurement data along with equivalent circuit models. The tolerance of the equivalent capacitance over frequency is focused upon in this paper. Within the 40 % tolerance band from the nominal value an improvement of 26 % and 197 % frequency band was achieved for the series and shunt variants respectively when compared to a commercial alternative. Further simulations show that with finer 3D printing resolutions, this frequency stable bandwidth can be further increased. Finally, an example design application of a halfwavelength microstrip resonator is presented in which the AECs’ Q factor is measured, and the its equivalent circuits are implemented and validated via simulations and measurements.</div
Antennas on quasi synthetic media
This paper examines the differences and/or similarities between some of the commonly used canonical equations describing the effective permittivity and permeability of heterogeneous substrates with dielectric or metallic inclusions, at microwave frequencies. Graphical results are presented for the different structures considered. Simulated results from heterogeneous mixtures with both dielectric and metallic inclusions are presented, and compared with results from the canonical equation representation. Simulated results of a patch antenna on a heterogeneous medium and on its homogeneous equivalent have also been presented
- …