Film, Video, and Digitality: An Analysis of Cultural Form in Time-based Media

This thesis examines the material properties of time-based image media, in particular live video. The project is practice-based with a theoretical underpinning drawn from the debates on form and meaning associated with Walter Benjamin

Polarisation dependent EBG surface with an inclined sheet via

This paper presents a novel polarisation dependent EBG (PDEBG) surface which makes use of sheet vias. The performance of the surface is analysed whilst varying the length, thickness and inclination of the vias. It is observed that the phase difference between the x-polarised and y-polarised component of the reflected wave can be controlled by varying these parameters. Furthermore, the surface exhibits a polarisation conversion property with potential use in a variety of antennas

Patch antenna directivity analysis using an equi-area method

The widespread exploitation of mobile cellular phones and use of wireless devices such as PDAs, in-vehicle Global Positioning System (GPS) receivers, and the future deployment of mobile satellite digital audio and video has developed a re-energized interest in efficient and accurate measurement techniques for antennas. This paper demonstrates directivity analysis of a patch antenna using a new fast, rotation-invariant spherical near-field antenna measurement technique. The method is based on an equi-area surface partitioning algorithm. The paper evaluates the sampling technique’s performance when compared with a normal spherical near-field measurement technique using equal angle sampling

Transmission line modelling of cylindrical cavity loaded with a slotted dielectric rod

© 2015 IEEE. This paper examines the effect of loading a microwave cylindrical cavity with radially slotted dielectric rod. Although, methods for the computation of the resonant frequency of dielectric loaded cavity have been presented in the literatures, the effect of placing radial slots on axisymmetric dielectric load in relation to the cavity resonance has not been studied. The study was carried out using a cylindrical TLM solver developed in MATLAB. A parametric check on the effect of varying the slot depth and width shows that the slot width has greater effect on the cavity resonance than the slot depth. It was also discovered that multiple narrow slots on the load affects the resonance frequency of the cavity more than a single wide slot. The effect of periodicity of the slots on the resonance frequency was also investigated

Stitched transmission lines for wearable RF devices

A novel stitched transmission line for wearable devices has been manufactured and tested to measure its scattering parameters from 0.04 to 4GHz. The stitched transmission line which is 150mm long consists of an inner conductor surrounded by a tubular insulating layer. For shielding purpose, the structure is stitched onto a denim material with a conductive thread with the aid of a novel manufacturing technique using a standard hardware. The S-Parameters were investigated with three different stitch angles 85°, 65° and 31° through simulation and experiments, demonstrating that the stitched transmission line can work usefully and consistently from 0.04 to 4GHz

Textile-to-rigid microstrip transition using permanent magnets

A novel transition between a rigid-substrate and a flexible-substrate microstrip for use in wearable devices is described. The contact force between the conductors of the two microstrips is supplied by a pair of rectangular magnets. A simulation and measurement study carried out on a test jig comprising a back-to-back pair of such transitions demonstrated an insertion loss of better than 0.5 dB/transition can be achieved in the range of 0-3 GHz

Microwave interconnects between textile and rigid substrates using permanent magnets

This paper presents a new approach to the problem of the transition between a textile microwave system and a regular microwave system. A simulated model of a transition between copper conductive line and textile conductive line is presented, with a comparison between simulated and measured results of the same model showing reasonable to good agreement. The work aims to create a full textile remountable and flexible microwave connector

Analysis, Optimization, and Hardware Implementation of Dipole Antenna Array for Wireless Applications

The antenna pattern synthesis is one of the signifiant problems in the phased array antenna. Pattern synthesis refers to the optimized weight excitation of each antenna element in order to steer the beam electronically without mechanically rotating the antenna. It can be achieved by using a combination of phase shifters and attenuator circuits. In this paper, a 2 by 2 dipole antennas with an RF beamforming circuit has been designed to steer the main beam along the The azimuth plane main beam coverage from 100° to 140° with a step size of 10° has been successfully optimized using a hybrid of the induced EMF method and a genetic algorithm. The optimization results were compared to the full-wave simulation technique implemented in Empire XCCel. The design is realistically implemented at 2.45GHz, with both simulation and measurement results shown. The measured reflection coefficient of the phased array antenna is −48dB at 2.56GHz. The feasibility of the beam synthesis has been validated successfully with the main beam being steered at 110°. The possibility of a fabrication discrepancy resulting in minor radiation degradation is also discussed in this research. The dipole antenna system with RF beamformer circuit can be applied to indoor positioning systems such as Wi-Fi, wireless local area network (WLAN), and fifth-generation

Design and SAR analysis of wearable antenna on various parts of human body, using conventional and artificial ground planes

This paper presents design and specific absorption rate analysis of a 2.4 GHz wearable patch antenna on a conventional and electromagnetic bandgap (EBG) ground planes, under normal and bent conditions. Wearable materials are used in the design of the antenna and EBG surfaces. A woven fabric (Zelt) is used as a conductive material and a 3 mm thicker Wash Cotton is used as a substrate. The dielectric constant and tangent loss of the substrate are 1.51 and 0.02 respectively. The volume of the proposed antenna is 113×96.4×3 mm3. The metamaterial surface is used as a high impedance surface which shields the body from the hazards of electromagnetic radiations to reduce the Specific Absorption Rate (SAR). For on-body analysis a three layer model (containing skin, fats and muscles) of human arm is used. Antenna employing the EBG ground plane gives safe value of SAR (i.e. 1.77W/kg2W/kg). The efficiency of the EBG based antenna is improved from 52 to 74%, relative to the conventional counterpart. The proposed antenna can be used in wearable electronics and smart clothing