Systems and Communications Commons^™

Breast Cancer Detection Using Interferometric Music: Experimental And Numerical Assessment, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Domenico Gaetano, Jacinta Browne, Max Ammann

Articles

Purpose: In microwave breast cancer detection, it is often beneficial to arrange sensors in close proximity to the breast. The resultant coupling generally changes the antenna response. As an a priori characterization of the radio frequency system becomes difficult, this can lead to severe degradation of the detection efficacy. The purpose of this paper is to demonstrate the advantages of adopting an interferometric multiple signal classification (I-MUSIC) approach due to its limited dependence from a priori information on the antenna. The performance of I-MUSIC detection was measured in terms of signal-to-clutter ratio (SCR), signal-to-mean ratio (SMR), and spatial displacement (SD) …

Using Near-Field Coupled Circularly Polarized Antennas As Frequency Independent Variable Phase-Shifters, Vit Sipal, Adam Narbudowicz, Max Ammann

Articles

This paper introduces a novel concept of frequency-independent variable phase-shifters. It is based on the use of circularly polarized (CP) antennas coupled in the near-field. For transmission between two CP antennas in the far-field, a rotation around the boresight axis produces a phase change in the transfer function. This concept is exploited and validated also for near-field coupling between two CP antennas. Therefore, two close-coupled CP antennas can act as a adjustable phase-shifter with the phase-shift controlled by the angle between the structures. The bandwidth depends on the CP bandwidth of the antenna. This concept is valuable for future phase-shifters …

Measuring Political Brand Equity In Ireland, Ewan Alexander Mcdonald, Roger Sherlock, John Hogan Dr

Articles

Measuring Political Brand Equity in the Republic of Ireland

This paper will apply cognitive mapping techniques to understand the manner in which political brand equity is formed and distributed amongst the four largest Irish political parties from the perspective of citizens. It assesses the fundamental aspects of branding and brand equity in the marketing and political marketing literatures and offers and overview of the market in question – the Irish political environment. Primary data was generated through the participation of 232 citizens in the political brand elicitation stage and a further 75 citizens were involved in the construction of the …

A Cavity-Backed Spiral Slot Antenna With Wide Axial Ratio Beamwidth For Gps System, Xiulong Bao, Max Ammann

Articles

A monofilar spiral slot antenna with a cavity-backed reflector is described. presented, which can achieve the performance of the wide Axial Ratio beamwave for Global Positioning System GPS system. It comprises an arrangement of a single printed spiral slots fed by a 50 Ω microstrip line. By using cavity-backed covering the slot structure, a wide axial ratio beamwidth performance is achieved in the GPS L1 frequency. The angle with less than 3 dB axial ratio at 1.575 GHz in the YoZ plane is about 215 degree. The measured results show that the HPWB beamwidths at 1.575 GHz are 100 degree …

Omnidirectional Microstrip Patch Antenna With Reconfigurable Pattern And Polarisation, Max Ammann, Xiulong Bao, Adam Narbudowicz

Articles

An omnidirectional microstrip patch antenna, capable of reconfiguring both polarisation and radiation pattern is proposed. It operates with two orthogonal ±45° slanted linear polarisations and can produce two dipole-like radiation patterns, providing 360° coverage in either the horizontal or elevation plane. With appropriate steering, this enables a single antenna to provide full spherical coverage for any polarisation. The reconfiguration is realised by phase shifting, thus does not require switching elements, such as MEMS or pin diodes embedded into antenna. The basic principles of operation are discussed and validated by numerical and measured data.

Leveraging Depolarization To Increase The Link Reliability For Wireless Sensors Operating In Hyper-Rayleigh Environments, Jeff Frolik, Vit Sipal, David J. Edwards

Articles

Wireless communications within enclosed environments such as aircraft and vehicles have been shown to experience fading with statistics that are worse than Rayleigh. Motivated by low-cost, low-complexity systems (e.g., wireless sensors) that may be deployed in such environments, this work explores the benefits of polarization diversity using very large data sets collected over a small area and over the 5-6 GHz band. The results also demonstrate that antennas capable of capturing depolarized signal components can significantly mitigate the harshest of fading environments.

Dual Band Lte Planar Inverted-F Antenna For M2m Applications, Abraham Loutridis, Matthias John, Max Ammann

Articles

A Planar Inverted-F Antenna for M2M applications is presented. The antenna is located on a rectangular ground plane and operates across both LTE frequency bands (690-960 MHz) and (1710-2690 MHz). The low cost antenna has omni-directional characteristics. The efficiency is better than 86% in both bands and the gain is more than 1.38 dBi across the whole frequency range. A parametric study of key geometrical parameters is reported.

Dual Circularly-Polarized Patch Antenna Using Even And Odd Feed-Line Modes, Adam Narbudowicz, Xiulong Bao, Max Ammann

Articles

This paper proposes a new patch antenna with dual circularly polarized capability at 2.575 GHz. The design exploits the even and odd modes in a coplanar waveguide transmission line and enables simultaneous right- and left-handed circular polarization, with two individual excitation ports. A patch antenna is fed by multimode transmission line and the advantages and disadvantages are discussed. A prototyped antenna realized up to 20 dB isolation between ports with S21 < -10dB bandwidth of 87 MHz. Realized gains for the two modes of operation are 5.77 and 7.23 dBic. The proposed structure is compact and easy to manufacture.

Footwear-Centric Body Area Network With Directional Uwb Antenna, Domenico Gaetano, Vit Sipal, Patrick Mcevoy, Max Ammann, C Brannigan, Louise Keating, Frances Horgan

Articles

A footwear-centric body area network employing a directional antenna is compared with waist-centric systems using omnidirectional and directional antennas. The impact of body movements on path gain is analysed for two bands at 3.99 GHz and 7.99 GHz. The path gain and data rate results demonstrate that footwear-centric configurations are equivalent or better than waist-centric body area networks.

Adaptive Ofdm For Wireless Interconnect In Confined Enclosures, Vit Sipal, Javier Gelabert, Christopher J. Stevens, Ben Allen, David Edwards

Articles

This letter considers and recommends OFDM with adaptive subcarrier modulation as a suitable candidate for wireless UWB communication in computer chassis. A rigorous measurement campaign studies the guaranteed spectral efficiency. It concludes that enhancement of the existing WiMedia OFDM systems with a bandwidth of 528 MHz in order to support adaptive OFDM would enable data-rates above 1 Gbps over short ranges, i.e. the spectral efficiency would be doubled. Moreover, the guaranteed spectral efficiency is shown to increase with bandwidth, i.e. the guaranteed data-rate increases better than linearly with bandwidth.

Comparison Of Non-Coherent Linear Detection Algorithms Applied To A 2-D Numerical Breast Model, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Max Ammann

Articles

A comparative analysis of an imaging method based on a multifrequency Multiple Signal Classification (MUSIC) approach against two common linear detection algorithms based on noncoherent migration is made. The different techniques are tested using synthetic data generated through CST Microwave Studio and a phantom developed from MRI scans of a mostly fat breast. The multifrequency MUSIC approach shows an overall superior performance compared to the noncoherent techniques. This letter reports that this highly performing algorithm does not require any antenna calibration or phase response estimation and allows the use of efficient and complex antenna geometries without difficult algorithm redefinitions.

A Compact Shorted Printed Monopole Antenna For Tv White Space Trials, Matthias John, Max Ammann

Conference Papers

This paper presents a compact shorted printed monopole antenna for machine-to-machine, remote sensing and rural wireless applications in the TV whitespace band from 470 MHz to 862 MHz. The antennas performance in this operating band is demonstrated.

Detecting Point-Like Sources Of Unknown Frequency Spectra, Raffaele Solimene, Giuseppe Ruvio, Angela Dell’Aversano, Antonio Cuccaro, Max Ammann, Rocco Pierri

Articles

The problem of detecting point-like sources whose frequency spectrum is unknown is addressed. Limitations of single-frequency approaches are identified by analytical as well as numerical arguments. To overcome these limits, different multifrequency approaches which combine frequency data incoherently are compared. In particular, a novel multifrequency MUSIC-like algorithm based on interferometric concepts is proposed. Results show that the algorithm outperforms other methods under comparison.

Dual-Band Omnidirectional Circularly Polarized Antenna, Adam Narbudowicz, Xiulong Bao, Max Ammann

Articles

A dual-band omnidirectional circularly polarized antenna is proposed. The antenna comprises back-to-back microstrip patches fed by a coplanar waveguide. A very low frequency ratio of 1.182 has been achieved, which can be easily tuned by adjusting four lumped capacitors incorporated into the antenna. An analysis of the omnidirectional circular polarization mechanism as well the dual band operation is provided and confirmed by numerical and experimental data. Key parameters to tune the resonant frequencies and the axial ratio have been identified. The prototype antenna provides omnidirectional circular polarization in one plane with cross polar isolation better than 12 dB for both …

Integration Of Inverted-F Antenna With Solar Cell Substitute, Oisin O’Conchubhair, Patrick Mcevoy, Max Ammann, Giuseppe Ruvio

Conference Papers

A study into the effect of a solar cell lattice on the performance of an Inverted-F antenna is presented. An FR-4 substrate with a lattice of copper electrodes printed on one side and a solid copper ground plane on the other is used to represent a polycrystalline solar cell. The effect of the lattice orientation on the performance of the Inverted-F antenna is discussed.

A 2.45/5.8 Ghz Folded Monopole Antenna For Wlan Applications, Abraham Loutridis, Matthias John, Giuseppe Ruvio, Max Ammann

Conference Papers

A probe-fed printed folded monopole antenna for WLAN applications is presented. The antenna operates at 2.45 GHz and 5.8 GHz, is compact and has omni-directional characteristics in both bands. A parametric study of key geometrical parameters is reported.

Circularly Polarized Terminal Antennas For Emerging Wireless Systems, Max Ammann, Xiulong Bao, Adam Narbudowicz

Conference Papers

Several types of omni-directional Circularly Polarized (CP) antennas are presented, which are employed by three different types of feedlines: Coplanar Waveguide (CPW) fed, Microstrip fed, and Differential-fed, to achieve omni-directional CP performances. The Dual-frequency Omni-directional CP antenna is proposed by using slot and inductor embedded into radiated patches. These omnidirectional CP antennas have potential application on GPS, WLAN and RFID systems.

Proximity Study Of A Uwb Directional Conformal Antenna On Water Pipe, Domenico Gaetano, Max Ammann, Patrick Mcevoy, Matthias John, Louise Keating, Frances Horgan

Articles

A preliminary study on the conformal properties of an antipodal exponentially tapered antenna placed on the surface of a flow meter system in the UWB range is presented. It was observed that the water effect can be mitigated by shifting the antenna away from the pipe surface.

An Enhanced Method To Measure Pulse Dispersion In Uwb Antennas, Antoine Dumoulin, Matthias John, Patrick Mcevoy, Max Ammann

Conference Papers

This paper will demonstrate a method to remove the dispersive effects of antennas and measurement equipment from a real time-domain measurement setup. By isolating the AUT transfer function, more accurate time-domain measurements can be achieved and agreement to simulation improved.

Vivaldi Array For Generation Of Uwb Circular Polarization, Adam Narbudowicz, Matthias John, Xiulong Bao, Max Ammann

Conference Papers

A two antenna array is proposed for generating circular polarization for an ultra-wideband system. It consists of two orthogonal antipodal vivaldi antennas and a feed network which provides the appropriate phase and amplitude over the band of interest. The proposed structure is low cost and easy to manufacture, offering an axial-ratio bandwidth of 74%.

Optimized Monopole And Dipole Antennas For Uwb Asset Tag Location Systems, Antoine Dumoulin, Matthias John, Max Ammann, Patrick Mcevoy

Articles

Miniaturized monopole and dipole antenna designs are reported with performances optimized for ultrawideband pulsed radio applications. The geometries are created using Bézier spline shapes, which have been refined with a genetic algorithm to simultaneously take account of both frequency- and time-domain criteria. Time-domain measurements of ultra wideband antennas with uniformly distributed energy across the full 3.1-10.6 GHz mask are reported for the first time and validate a new approach to minimization of pulse dispersion effects in the antenna designs.

Optimised Tapered-Slot Antenna For Real Time Location Systems, Antoine Dumoulin, Matthias John, Patrick Mcevoy, Max Ammann

Conference Papers

The design of a directional UWB tapered slot antenna for use within an asset tracking system is reported. The spline-based geometry was refined with a local optimization algorithm and a square root raised cosine pulse. The time-domain performance of the antenna is dependent on the optimisation method.

A Microfiber Coupler Tip Thermometer, Ming Ding, Pengfei Wang, Gilberto Bramilla

Articles

A compact thermometer based on a broadband microfiber coupler tip is demonstrated. This sensor can measure a broad temperature interval ranging from room temperature to 1283 degrees C with sub-200 mu m spatial resolution. An average sensitivity of 11.96 pm/degrees C was achieved for a coupler tip with similar to 2.5 mu m diameter. This is the highest temperature measured with a silica optical fiber device. (C)2012 Optical Society of America

Evanescent Field Coupling Between Two Parallel Close Contact Sms Fiber Structures, Qiang Wu, Youqiao Ma, Jinhui Yuan, Yuliya Semenova, Pengfei Wang, Chongxiu Yu, Gerald Farrell

Articles

We proposed a novel optical coupling technique based on two parallel singlemode-multimode- singlemode (SMS) fiber structures. This technique utilizes one SMS structure to excite multiple cladding modes within an output singlemode fiber. The excited multiple cladding modes will be coupled to the input SMF in the second SMS structure by placing the two SMS fiber structures in parallel and in close contact each other. The coupled cladding modes will be re-coupled to a guided core mode by the second SMS fiber structure. Theoretical analysis for such technique was provided and experimentally we have achieved a pass band spectral response with …

Germanium Microsphere High-Q Resonator, Pengfei Wang, Timothy Lee, Ming Ding, Anirban Dhar, Thomas Hawkins, Paul Foy, Yuliya Semenova, Qiang Wu, Jayanta Sahu, Gerald Farrell, John Ballato, Gilberto Brambilla

Articles

In this Letter, the fabrication and characterization of a microsphere resonator from the semiconductor germanium is demonstrated. Whispering gallery modes are excited in a 46 μm diameter germanium microsphere resonator using evanescent coupling from a tapered silica optical fiber with a waist diameter of 2 μm. Resonances with Q factors as high as 3.8×104 at wavelengths near 2 μm are observed. Because of their ultrahigh optical nonlinearities and extremely broad transparency window, germanium microsphere resonators offer the potential for optical processing devices, in particular at long wavelengths, such as around 2 μm.

A Novel Qos-Aware Mpeg-4 Video Delivery Algorithm Over The Lossy Ieee 802.11 Wlans To Improve The Video Quality, Tanmoy Debnath

Doctoral

Video traffic is bursty in nature and has different network requirements compared to other types of traffic (e.g. voice, data) in terms of bandwidth, delay, jitter, and loss etc. So it becomes important to manage video traffic on a WLAN carefully to achieve acceptable levels of Quality of Service (QoS). The unique contribution of this work is that it presents experimental and simulation studies of the performance of real video content streamed over WLAN networks. Under various test scenarios the performance of the WLAN network in terms of delay, loss, throughput etc. is analysed in the presence of background traffic. …

Monofilar Spiral Slot Antenna For Dual-Frequency Dual-Sense Circular Polarization, Xiulong Bao, Max Ammann

Articles

A dual-band antenna with right-hand circular polarization for the first frequency and the counter polarization at the second frequency is realized with compact printed spiral slots. The coupled spiral slots are fed by a 50 Ω microstrip line. Dual-sense circularly-polarized performance is achieved by realizing oppositely-directed current rotation for the two frequency bands. A parametric study shows that the additional slot significantly improves the bandwidth for both frequency bands. Measured results show that the fractional impedance bandwidth is greater than 18% for both bands. The 3 dB axial-ratio bandwidths are 4.5% and 3.5% for the RHCP and LHCP bands, respectively.

Wideband Dual-Frequency Dual-Polarized Dipole-Like Antenna, Xiulong Bao, Max Ammann

Articles

A wideband dual-frequency dual-polarized printed antenna is proposed for LTE, WLAN, and UWB systems. The dual-band antenna provides wide impedance bandwidths of 74% with respect to the center frequency of 2.725 GHz, and 39% with respect to the center frequency of 7.15 GHz. An open slot in the ground plane between the feed arms provides an orthogonal path to realize an embedded circularly polarized band at 2.35 GHz with an axial-ratio bandwidth of 16%. Dual-band characteristics are achieved by an asymmetrical dipole-like element and the coupling configuration between the T-shaped feed line and the wide ground-plane slot.

Printed Circularly-Polarized Antenna With Ultra-Wide Axial-Ratio Bandwidth, Xiulong Bao, Max Ammann

Articles

A circularly polarised printed dipole-like antenna employing asymmetrical arms and an orthogonal slit in the ground plane is presented. It is fed by a stepped microstrip line which connects to the shorter arm. By utilising surface currents on the asymmetrical arms and the orthogonal feedline structure, circular polarisation is realised. Experimental and numerical data are in agreement and the measured results show a fractional impedance bandwidth of 41.3% (1.77–2.69 GHz) and a wide axial-ratio bandwidth of 38.4% (1.81–2.67 GHz).

Touch2query Enabled Mobile Devices: A Case Study Using Openstreetmap And Iphone, Junjun Yin, James Carswell

Conference papers

This paper describes our mobile spatial interaction (MSI) prototype Touch2Query which presents the idea of using the touch screen on mobile devices to assist in performing ad-hoc spatial queries. This approach differs from conventional mobile LBS applications where the query shape (search space) is limited to either a bounding box or radius. Instead, we provide functionality that allows users to interactively draw any desired query shape overlaid on an area of interest directly on a mobile device with their finger by combining vector primitives such as circles, polygons, polylines, and points. With the help of location and orientation aware mobile …