School of Electrical and Electronic Engineering

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Now showing 1 - 20 of 3329

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1/f, g-r and burst noise used as a screening threshold for reliability estimation of optoelectronic coupled devices
(Pergamon-Elsevier Science Ltd, 2000) Xu, J.; Abbott, D.; Dai, Y.
In this paper the theoretical analysis of noise sources in Optoelectronic Coupled Devices (OCDs) is given and the relation between typical defects and 1/f, g–r and burst noise is described. According to statistical and experimental results, a threshold to screen potential devices with excess noise is derived, which has been proved theoretically that the screening criterion is reasonable. Moreover, the experimental results show that the method is of practical value.
Open Access
2-D wavelet segmentation in 3-D T-ray tomography
(The Institute of Electrical and Electronic Engineers Inc., 2007) Yin, X.; Ng, B.; Ferguson, B.; Mickan, S.; Abbott, D.
In this letter, segmentation techniques for terahertz (T-ray) computed tomographic (CT) imaging are investigated. A set of linear image fusion and novel wavelet scale correlation segmentation techniques is adopted to achieve material discrimination within a 3-D object. The methods are applied to a T-ray CT image dataset taken from a plastic vial containing a plastic tube. This setup simulates the imaging of a simple nested organic structure, which provides an indication of the potential for using T-ray CT imaging to achieve T-ray pulsed signal classification of heterogeneous layers
Open Access
2-stage RC ladder: solution of a noise paradox
(American Institute of Physics, 2000) Weiss, L.; Abbott, D.; Davis, B.; International Conference on Unsolved Problems of Noise and Fluctuations (2nd : 1999 : Adelaide, Australia); Abbott, D.; Kish, L.B.
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2011 Index IEEE Antennas and Wireless Propagation Letters, vol. 10
(Institute of Electrical and Electronics Engineers, 2011) Abbott, D.
This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during 2011, and items from previous years that were commented upon or corrected in 2011. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author’s name. The primary entry includes the coauthors’ names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author’s name, the publication abbreviation, the year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index.
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275-GHz Planar High-Gain Resonant Cavity Antenna with Effective Medium
(IEEE, 2023) Li, M.S.; Fumeaux, C.; Withayachumnankul, W.; International Symposium on Antennas and Propagation (ISAP) (31 Oct 2022 - 3 Nov 2022 : Sydney, NSW)
In this paper, we present a planar high-gain resonant cavity antenna (RCA) with an integrated waveguide feed for the WR-3 frequency band from 220-330 GHz. The conventional extended hemispherical lens and resonant air cavity are replaced by two effective medium layers of cylindrical hole arrays, which can be fabricated by direct laser drilling on both sides of a high-resistivity float-zone (HRFZ) silicon wafer. The proposed design presents an advantage particularly in its low profile, with an overall thickness of only two wavelengths. The lens antenna is designed through full-wave simulations, and the achieved results suggest a maximum broadside gain of 20 dBi at 275 GHz, with a 3-dB bandwidth of around 18%.
Open Access
2D scanning Rotman lens structure for smart collision avoidance sensors
(SPIE, 2004) Hall, L.; Hansen, H.; Abbott, D.; Microelectronics, MEMS, and Nanotechnology (2003 : Perth, Australia); Abbott, D.; Eshraghian, K.; Musca, C.A.; Pavlidis, D.; Weste, N.
Although electronically scanned antenna arrays can provide effective mm-wave search radar sensors, their high cost and complexity are leading to the consideration of alternative beam-forming arrangements. Rotman lenses offer a compact, rugged, reliable, alternative solution. This paper considers the design of a microstrip based Rotman lens for high-resolution, frequency-controlled scanning applications. Its implementation in microstrip is attractive because this technology is low-cost, conformal, and lightweight. A sensor designed for operation at 77 GHz is presented and an ∼ 80° azimuthal scan over a 30 GHz bandwidth is demonstrated.
Open Access
3-D broadband ground-based polarimetric SAR data processing for the monitoring of vegetation growth variations
(Institute of Electrical and Electronics Engineers, 2004) Zhou, Zheng-Shu; Hamasaki, Tadashi; Sato, Motoyuki; Boerner, Wolfgang-Martin; IEEE International Geoscience and Remote Sensing Symposium (2004 : Anchorage, Alaska); IGARSS 2004; School of Electrical and Electronic Engineering
SAR is usually used for airborne or space borne remote sensing. It can also advantageously be exploited in a ground-based radar imaging system named Ground-based SAR (GB-SAR). We extended earlier approaches and developed an ultra-wideband, ground-based, fully polarimetric SAR (Pol-GB-SAR) system for the monitoring of vegetation growth variations. Measurements on three type trees in different conditions were carried out by the developed SAR system. We proposed effective three-dimensional (3-D) broadband Pol-GB-SAR data processing algorithms in the paper. In situ polarimetric calibration obviously improved the features of the system. 3-D images were reconstructed from the acquired data by a series of signal processing procedures based on a variety of wave equation migration methods. By implementing methods of radar polarimetry, the broadband GB-SAR system has possibility for monitoring changes in tree structure characteristics due to seasonal variations. Interpreted results demonstrated the target scattering characteristics in different vegetation growth situations showed good agreement with the ground truth.
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3-D low earth orbit vector estimation of Faraday rotation and path delay
(IEEE, 2015) Lawrence, N.; Hansen, H.; Abbott, D.
An electromagnetic wave propagating through the ionosphere is subject to path delay and the depolarizing effect of Faraday rotation, both of which are dependent on global position and geometry. These effects introduce error and consequently reduce the range resolution of remote sensing polarimetric measurements. Satellite-to-ground communications may be adversely altered by these effects so as to inhibit signal reception. The work presented here introduces a simple vectorized model for a large-field-of-view, low-Earth-orbit, satellite system that yields Faraday rotation and path delay according to global position and geometric parameters. Comparison is made with current models, through the simulation of Faraday rotation and path delay. The presented work may extend the range over which Faraday rotation and path delay estimation are reliable. The work presented forms part of a large-field-of-view, low-Earth-orbit satellite model exploiting multiple-input multiple-output polarimetry in three dimensions
Metadata only
3-D monitoring of trees by polarimetric GB-SAR
(2006) Zhou, Zheng-Shu; Boerner, Wolfgang-Martin; Sato, Motoyuki; European Conference on Synthetic Aperture Radar (6th : 2006 : Dresden, Germany); EUSAR 2006; School of Electrical and Electronic Engineering
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3-D system-on-system (SoS) biomedical-imaging architecture for health-care applications
(IEEE, 2010) Lee, S.; Kavehei, O.; Hong, Y.; Cho, T.; You, Y.; Cho, K.; Eshraghian, K.
This paper presents the implementation of a 3-D architecture for a biomedical-imaging system based on a multilayered system-on-system structure. The architecture consists of a complementary metal-oxide semiconductor image sensor layer, memory, 3-D discrete wavelet transform (3D-DWT), 3-D Advanced Encryption Standard (3D-AES), and an RF transmitter as an add-on layer. Multilayer silicon (Si) stacking permits fabrication and optimization of individual layers by different processing technology to achieve optimal performance. Utilization of through silicon via scheme can address required low-power operation as well as high-speed performance. Potential benefits of 3-D vertical integration include an improved form factor as well as a reduction in the total wiring length, multifunctionality, power efficiency, and flexible heterogeneous integration. The proposed imaging architecture was simulated by using Cadence Spectre and Synopsys HSPICE while implementation was carried out by Cadence Virtuoso and Mentor Graphic Calibre.
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3D SAR beamforming under a foliage canopy from a single pass
(IEEE, 2015) Pincus, P.; Preiss, M.; Gray, D.; 40th IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2015) (19 Apr 2015 - 24 Apr 2015 : South Brisbane)
Coherent detection of changes on the ground under a forest canopy by repeat-pass synthetic aperture radar (SAR) imaging is problematic due to the mixture of ground and canopy responses. 3D SAR imaging, by beamforming data from multiple low-frequency acrosstrack acquisitions, offers a way to separate the forest components in height. However, data acquired from multiple passes require precise registration of the flight tracks, which is often not possible, particularly for small airborne platforms. This study analyses the potential for SAR imaging of the ground under a forest canopy using data from a single pass of a multichannel across-track radar system. We focus in particular on the case of a two-channel alternating-transmit interferometer giving three effective input channels. 3D image formation in one pass by phase-preserving adaptive beamforming is shown to provide sufficient attenuation of the interference from a model forest volume to permit a reasonable estimation of the ground coherence across two passes for coherent change detection.
Metadata only
5G Terrestrial Networks: Mobility and Coverage-Solution in Three Dimensions
(IEEE, 2017) Lawrence, N.P.; Ng, B.W.-H.; Hansen, H.J.; Abbott, D.
The next generation of wireless communications, which is proposed to operate in the mmWave region of the electromagnetic spectrum, offers the potential of high-data rate and increased coverage in response to a rapid growth of mobile data traffic. Operation in an mmWave channel is subject to physical and current technical limitations compared with conventional terrestrial microwave channel propagation. In this paper, the effects of antenna misalignment are considered in an mmWave channel through polarization mismatch. Tri-orthogonal polarization diversity is suggested as a means for mitigating misalignment effects and offering increased link performance over a majority of antenna orientations. A known physically realized planar antenna design offering such diversity is highlighted.
Metadata only
6 GHz microstrip patch antennas with PEDOT and polypyrrole conducting polymers
(IEEE, 2010) Verma, A.; Weng, B.; Shepherd, R.; Fumeaux, C.; Truong, V.; Wallace, G.; Bates, B.; International Conference on Electromagnetics in Advanced Applications (2010 : Sydney, NSW)
Two 6 GHz microstrip patch antennas made from conducting polymers with relatively low DC conductivity such as PEDOT (10000 S/m) and PPy (2000 S/m) are presented. The performance of these patch antennas is compared with a similar copper patch antenna. The results indicate that it is possible to obtain reasonable performance albeit with modest radiation efficiencies. The PEDOT antenna achieved a maximum gain of 2.2 dB, while the PPy antenna reached a gain of 3.8 dB, as against 6.0 dB for a corresponding Cu patch antenna The results confirm the potential of polymer materials for microwave antennas and suggest that CPs may be of use in other passive microwave circuit applications.
Metadata only
60 ghz aperture-coupled dielectric resonator antennas fed by a half-mode substrate integrated waveguide
(IEEE-Inst Electrical Electronics Engineers Inc, 2010) Lai, Q.; Fumeaux, C.; Hong, W.; Vahldieck, R.
Dielectric resonator antennas (DRAs) fed by a halfmode substrate integrated waveguide (HMSIW) are proposed and studied in this paper. The investigated antenna configuration consists of a dielectric resonator (DR) mounted on the conducting back plane of an HMSIW. Energy is coupled from the interior HMSIW to the DR through an aperture between them. Using this excitation scheme, a 60 GHz linearly polarized HMSIW-fed DRA is first designed by applying a transverse rectangular slot to feed a dielectric cylinder. This design experimentally exhibits a bandwidth of 24.2% for S11 < -10 dB. In particular, a gain higher than 5.5 dB and a radiation efficiency between 80% and 92% are obtained over the whole operation band, indicating that the HMSIW can be an efficient feed for DRAs operating around 60 GHz. In addition to this linearly polarized example, a DRA of circular polarization, coupled through a pair of cross slots, is also designed, presenting a measured 3-dB axial ratio bandwidth of 4.0%.
Metadata only
60GHz radios: enabling next-generation wireless applications
(IEEE - Institute of Electrical and Electronics Engineers, 2005) Howarth, J.; Lauterbach, A.; Boers, M.; Davis, L.; Parker, A.; Harrison, J.; Rathmell, J.; Batty, M.; Cowley, W.; Burnet, C.; Hall, L.; Abbott, D.; Weste, N.; TENCON (2005 : Melbourne, Australia)
Up to 7 GHz of continuous bandwidth centred around 60 GHz has been allocated worldwide for license free wireless communications. Highly attenuated due to oxygen absorption and small in wavelength, this band is ideal for extremely high data rate wireless data applications. These include numerous WPAN/WLAN applications such as home multimedia streaming. Traditional RF circuits used in this band are based on expensive compound semiconductor technologies. However for viable consumer applications, alternatives must be found. SiGe and CMOS based circuits are showing promise for enabling this technology at a price within reach of the consumer. This paper summarises a joint project aimed at developing high rate consumer level mm-wave wireless data systems. In particular, results to date in our RF design efforts are summarised.
Metadata only
802.11 wireless network extended service set model
(IEEE - Institute of Electrical and Electronics Engineers, 2004) Sudarev, J.; White, L.; International Workshop on Wireless Ad-Hoc Networks (2004 : Oulu, Finland)
With the limited radio spectrum allocated to wireless communications and increasing population of wireless users overloaded conditions might become a major problem. Admission control can be used to fully utilize available bandwidth and provide desirable quality of service. A mathematical model of the wireless network is required to develop an admission control scheme. In this paper we consider simple extended service set (ESS) model as a continuous time discrete states nonhomogeneous quasi-birth-and-death Markov process. Matrix analytic methods are used to efficiently obtain the stationary distribution of the process. Various characteristics of the modelled extended service set are obtained based on stationary distribution.
Metadata only
A 1 GHz differential 2nd-order lowpass sigma delta modulator in CMOS for wireless receivers
(SPIE, 2004) Zhu, Y.; Al-Sarawi, S.; Liebelt, M.; Microelectronics, MEMS, and Nanotechnology (2003 : Perth, Australia); Abbott, D.; Eshraghian, K.; Musca, C.; Pavlidis, D.; Weste, N.
This paper presents the design of a 1 GHz continuous-time second order Lowpass Sigma Delta Modulator (LPSDM). The design is intended to meet the future requirements of wideband wireless receivers. The continuous-time Noise Transfer Function (NTF) for the modulator is realized using two Gm-C integrators with negative transconductance feedback and three linearized Gm elements. A three-stage delayed comparator is employed for designing the one bit quantizer, therefore a delayed NTF had to be synthesized. The presented target design is 0.18µm CMOS process. The designed chip uses both 3.3V and 1.8V MOSFETs and consumes 80mW including the clock driver and the output buffer. The performance of the modulator based on post layout simulation is 11 bits for a 5 MHz bandwidth and 8.6 bits for an 11MHz bandwidth.
Metadata only
A 16 pixel yaw sensor for velocity estimation
(SPIE, 2006) Rajesh, S.; Abbott, D.; O'Carroll, D.; Microelectronics, MEMS, and Nanotechnology (2005 : Brisbane, Australia); Nicolau, D.V.
The insect visual system, with its simplicity and efficiency has gained widespread attention and many biologically inspired models are being used for motion detection and velocity estimation tasks. One of the earliest and most efficient models among them is the Reichardt correlator model. In this paper, we have elaborated the basic Reichardt correlator to include spatial and temporal pre-filtering and additional non-linearites which are believed to be present in the fly visual system to develop a simple yaw sensor. We have used just 16 elaborated EMDs and it is seen that this sensor can detect rotational motion at angular velocities up to several thousand degrees per second. The modelling of these sensors make us realize that the VLSI implementation of such simple detectors can have varied applications for flight control in different fields.
Metadata only
A 2 GHz polypyrrole microstrip patch antenna on plexiglas ™ substrate
(IEEE, 2009) Verma, A.; Fumeaux, C.; Truong, V.; Bates, B.; Asia-Pacific Microwave Conference (2009 : Singapore)
A Microstrip Patch Antenna (MPA) has been fabricated using a Conducting Polymer (CP), Polypyrrole (PPy) as radiating patch on a transparent 3mm thick Plexiglas™ substrate. The bulk DC conductivity of the PPy patch is 2000 S/m and its thickness 120 mu pm. The MPA was designed for operating at 2 GHz. A similar antenna with Copper (Cu) patch on Plexiglas™ was also fabricated for validating the simulation of PPy antenna and comparing its performance. The results show that the PPy antenna reaches a gain of 5.01 dB at 2.18 GHz as against 6.26 dB at 2.2 GHz for a corresponding Cu patch antenna. The conduction efficiency of Cu-patch antenna is around 80% while that of PPy-patch antenna is around 60%. The results suggest that it might be possible to use CPs in other passive microwave circuit applications.
Restricted
A 5.8-GHz flexible microstrip-fed slot antenna realized in PEDOT:PSS conductive polymer
(IEEE, 2016) Chen, S.; Fumeaux, C.; Chivers, B.; Shepherd, R.; 2016 IEEE International Symposium on Antennas and Propagation (APSURSI 2016) (26 Jun 2016 - 1 Jul 2016 : Fajardo, Puerto Rico)
A flexible 5.8-GHz microstrip-fed slot antenna realized in thin films of conductive polymer PEDOT:PSS is presented. As a result of the highly conductive and flexible polymeric film utilization, the antenna has a high efficiency of 82% and fully reversible conformability. A PEDOT and a reference copper antenna prototypes have been fabricated and experimentally characterized. The good agreement between simulations and measurements suggests that conductive polymers are a promising class of non-metallic conducting materials for antenna engineering, particularly for conformal designs.

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