David Victor Thiel

Design Methods for 3D RFID Antennas Located on a Conducting Ground Plane (2009)

Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor, O'Keefe, Steven Gregory

Based on 2D meander line methods, 3 times 3 times 3 point, symmetrical, 3D dipole antennas structure was investigated exhaustively to identify those configurations with the highest efficiency and...

Tapered Meander Line Antenna for Maximum Efficiency and Minimal Environmental Impact (2009)

Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor, O'Keefe, Steven Gregory

The environmental impact of mass produced, disposable antennas is a major consideration in such areas as RFID, cellular telephones and keyless entry devices. The selection of environmentally benign...

Tapered Wire Antenna Design for Maximum Efficiency and Minimal Environmental Impact (2008)

Thiel, David Victor, Mohammadzadeh Galehdar, Amir Abas, O'Keefe, Steven Gregory

Antenna efficiency is an important parameter in RFID range and power consumption. Screen printed antennas often have poor conductivity and so increased loss. Designers offset this loss by increasing...

Sustainable Electronics: Wireless Systems with Minimal Environmental Impact (2008)

Thiel, David Victor

Global warming, greenhouse gas emissions and e-waste are all major issues world-wide. Antennas are now a very common component in most consumer electronic devices (eg computers, telephones, toys,...

Tapered Wire Antenna Design for Maximum Efficiency and Minimal Environmental Impact (2008)

Thiel, David Victor, Mohammadzadeh Galehdar, Amir Abas, O'Keefe, Steven Gregory

Antenna efficiency is an important parameter in RFID range and power consumption. Screen printed antennas often have poor conductivity and so increased loss. Designers offset this loss by increasing...

Sustainable Electronics: Wireless Systems with Minimal Environmental Impact (2008)

Thiel, David Victor

Global warming, greenhouse gas emissions and e-waste are all major issues world-wide. Antennas are now a very common component in most consumer electronic devices (eg computers, telephones, toys,...

Rectangular Patch with Parasitic Folded Dipoles: A Reconfigurable Antenna (2008)

Palanteil, Elyas, O'Keefe, Steven Gregory, Thiel, David Victor

In this paper, the tuning and steering of a rectangular patch antenna is controlled by switching the patch and folded dipoles configuration. This reconfigurable antenna is controlled by the changing...

Rectangular Patch with Parasitic Folded Dipoles: A Reconfigurable Antenna (2008)

Palanteil, Elyas, O'Keefe, Steven Gregory, Thiel, David Victor

In this paper, the tuning and steering of a rectangular patch antenna is controlled by switching the patch and folded dipoles configuration. This reconfigurable antenna is controlled by the changing...

Exposure zones near parasitic elements in high powered antennas (2008)

Thiel, David Victor

This simple investigation, and results from many other experimental measurements and theoretical investigations demonstrate the following: a) There is a region close to the parasitic element where...

Local Search for Ant Colony System to Improve the Efficiency of Small Meander Line RFID Antennas (2008)

Weis, Gerhard, Lewis, Andrew, Randall, Marcus, Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor

The efficient design of meander line antennas for RFID devices is a significant real-world problem. Traditional manual tuning of antenna designs is becoming impractical for larger problems. Thus the...

Switched Parasitic Patch Antenna Array Using Thirteen Hexagonal Shaped Elements (2008)

Lu, Junwei, Thiel, David Victor

A novel circularly polarized smart patch antenna array with hexagonal elements was designed as a hub for indoor/outdoor mobile wireless computing networks. A frequency domain finite element method...

Tapered Wire Antenna Design for Maximum Efficiency and Minimal Environmental Impact (2008)

Thiel, David Victor, Mohammadzadeh Galehdar, Amir Abas, O'Keefe, Steven Gregory

Antenna efficiency is an important parameter in RFID range and power consumption. Screen printed antennas often have poor conductivity and so increased loss. Designers offset this loss by increasing...

Sustainable Electronics: Wireless Systems with Minimal Environmental Impact (2008)

Thiel, David Victor

Global warming, greenhouse gas emissions and e-waste are all major issues world-wide. Antennas are now a very common component in most consumer electronic devices (eg computers, telephones, toys,...

Rectangular Patch with Parasitic Folded Dipoles: A Reconfigurable Antenna (2008)

Palanteil, Elyas, O'Keefe, Steven Gregory, Thiel, David Victor

In this paper, the tuning and steering of a rectangular patch antenna is controlled by switching the patch and folded dipoles configuration. This reconfigurable antenna is controlled by the changing...

Dual Frequency Inverted-S Antenna for Mobile Handset Devices (2007)

Lu, Junwei, Thiel, David Victor, O'Keefe, Steven Gregory

A novel dual frequency band inverted-S antenna (ISA) using low profile PCB configuration developed for mobile handset devices in wireless communications is presented. The ISA consists of two...

Antenna efficiency calculations for electrically small, RFID antennas (2007)

Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor, O'Keefe, Steven Gregory

Radio frequency identification (RFID) antenna efficiency is an important component of link budget design. A method of moments technique based on the summation of segment currents compares favorably...

Measurement of energy expenditure in elite athletes using MEMS-based triaxial accelerometers (2007)

Wixted, Andrew James, Thiel, David Victor, Hahn, Allan G., Gore, Christopher J., Pyne, David B., James, Daniel Arthur

Fitness development and performance assessment of elite athletes requires an understanding of many physiological factors, many of these are direct and indirect measures of athlete energy expenditure....

Using ant colony optimisation to improve the efficiency of small meander line RFID antennas (2007)

Randall, Marcus, Lewis, Andrew, Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor

Increasing the efficiency of meander line antennas is an important real-world problem within radio frequency identification (RFID). Meta-heuristic search algorithms, such as ant colony optimisation,...

Effect of mutual coupling on the energy requirement of mimo-based wireless sensor networks (2007)

Abbosh, Amin M., Thiel, David Victor

A theoretical model was developed to estimate effect of the mutual coupling on the energy requirement of a multiple-input multiple-output (MIMO) based wireless sensor network (WSN). Clustered channel...

Energy efficient wireless sensor networks (2007)

Abbosh, Amin M., Thiel, David Victor

A theoretical model is presented to estimate the energy requirements of multiple-input multiple-output (MIMO) systems when used in wireless sensor networks (WSN) assuming clustered channel modeling,...

Dual Frequency Inverted-S Antenna for Mobile Handset Devices (2007)

Lu, Junwei, Thiel, David Victor, O'Keefe, Steven Gregory

A novel dual frequency band inverted-S antenna (ISA) using low profile PCB configuration developed for mobile handset devices in wireless communications is presented. The ISA consists of two...

Corona Onset Voltage at High Frequency for an Isolated, Cylindrical Electrode (2007)

Price, William O., Drapala, John, Thiel, David Victor, Olsen, Robert G.

Corona on antennas or transmission lines is a significant source of electromagnetic interference on aircraft. A corona onset criterion, which describes breakdown in nonuniform RF fields, is derived...

Corona Onset Voltage at High Frequency for an Isolated, Cylindrical Electrode (2007)

Price, William O., Drapala, John, Thiel, David Victor, Olsen, Robert G.

Corona on antennas or transmission lines is a significant source of electromagnetic interference on aircraft. A corona onset criterion, which describes breakdown in nonuniform RF fields, is derived...

Antenna efficiency calculations for electrically small, RFID antennas (2007)

Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor, O'Keefe, Steven Gregory

Radio frequency identification (RFID) antenna efficiency is an important component of link budget design. A method of moments technique based on the summation of segment currents compares favorably...

Measurement of energy expenditure in elite athletes using MEMS-based triaxial accelerometers (2007)

Wixted, Andrew James, Thiel, David Victor, Hahn, Allan G., Gore, Christopher J., Pyne, David B., James, Daniel Arthur

Fitness development and performance assessment of elite athletes requires an understanding of many physiological factors, many of these are direct and indirect measures of athlete energy expenditure....

Using ant colony optimisation to improve the efficiency of small meander line RFID antennas (2007)

Randall, Marcus, Lewis, Andrew, Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor

Increasing the efficiency of meander line antennas is an important real-world problem within radio frequency identification (RFID). Meta-heuristic search algorithms, such as ant colony optimisation,...

Effect of mutual coupling on the energy requirement of mimo-based wireless sensor networks (2007)

Abbosh, Amin M., Thiel, David Victor

A theoretical model was developed to estimate effect of the mutual coupling on the energy requirement of a multiple-input multiple-output (MIMO) based wireless sensor network (WSN). Clustered channel...

Energy efficient wireless sensor networks (2007)

Abbosh, Amin M., Thiel, David Victor

A theoretical model is presented to estimate the energy requirements of multiple-input multiple-output (MIMO) systems when used in wireless sensor networks (WSN) assuming clustered channel modeling,...

Flexible, light-weight antenna at 2.4GHz for athlete clothing (2007)

Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor

Linearly polarized rectangular patch antennas printed on light-weight cotton clothing are subject to both convex and concave bending. Changes in resonant frequency resulting from H plane bending are...

Symmetry problems in switched parasitic smart antennas (2007)

Palantei, Elyas, Thiel, David Victor

Radiation pattern symmetry of a switched parasitic smart antenna is important for full 360deg azimuthal coverage. The ideal symmetrical beam patterns are hard to achieve in reality due to a number of...

Efficiency variations in electrically small, meander line RFID antennas (2007)

Mohammadzadeh Galehdar, Amir Abas, Thiel, David Victor, O'Keefe, Steven Gregory, Kingsley, Simon Philip

Not all meander line dipole antennas (MLDAs) plotted on the same grid necessarily have similar characteristics. MLDAs can be optimized for best efficiency, lowest resonant frequency or highest...

Dual Frequency Inverted-S Antenna for Mobile Handset Devices (2007)

Lu, Junwei, Thiel, David Victor, O'Keefe, Steven Gregory

A novel dual frequency band inverted-S antenna (ISA) using low profile PCB configuration developed for mobile handset devices in wireless communications is presented. The ISA consists of two...

Corona Onset Voltage at High Frequency for an Isolated, Cylindrical Electrode (2007)

Price, William O., Drapala, John, Thiel, David Victor, Olsen, Robert G.

Corona on antennas or transmission lines is a significant source of electromagnetic interference on aircraft. A corona onset criterion, which describes breakdown in nonuniform RF fields, is derived...

Dual Frequency Band Inverted-S Antenna for Mobile Handset Devices (2006)

Lu, Junwei, Suzuki, Takeharu, Thiel, David Victor, O'Keefe, Steven Gregory

A novel dual frequency band inverted-S antenna (ISA) using low profile PCB configuration developed for mobile handset devices in wireless communications is presented. The ISA consists of two...

Validation of a soil interface model to account for apparent aberrations in capacitive soil moisture sensors (2006)

Johnson, Peter, Watling, Kym Marjorie, Thiel, David Victor, James, Daniel Arthur

In this paper the operation of capacitive soil moisture sensors are modeled using an electrical circuit analogue. This model aims to predict the response of capacitive sensors for a variety of soil...

Innovative techniques for extending the range and node limits in Bluetooth-based wireless sensor networks (2006)

Fraser, Matthew James, James, Daniel Arthur, Thiel, David Victor

Wireless networks for sensor applications are required to support an adequate data throughput, range, node density and must consume as little power as possible. The Bluetooth specification has been...

Dual Frequency Band Inverted-S Antenna for Mobile Handset Devices (2006)

Lu, Junwei, Suzuki, Takeharu, Thiel, David Victor, O'Keefe, Steven Gregory

A novel dual frequency band inverted-S antenna (ISA) using low profile PCB configuration developed for mobile handset devices in wireless communications is presented. The ISA consists of two...

An Investigation of an Electronically Switched Beam Smart Antenna: Numerical and Empirical Approaches (2006)

Thiel, David Victor

An investigation of an electronically switched beam smart antenna through numerical and empirical approaches is presented. This paper examines two scenarios of switched beam smart antenna realization...

Validation of a soil interface model to account for apparent aberrations in capacitive soil moisture sensors (2006)

Johnson, Peter, Watling, Kym Marjorie, Thiel, David Victor, James, Daniel Arthur

In this paper the operation of capacitive soil moisture sensors are modeled using an electrical circuit analogue. This model aims to predict the response of capacitive sensors for a variety of soil...

Innovative techniques for extending the range and node limits in Bluetooth-based wireless sensor networks (2006)

Fraser, Matthew James, James, Daniel Arthur, Thiel, David Victor

Wireless networks for sensor applications are required to support an adequate data throughput, range, node density and must consume as little power as possible. The Bluetooth specification has been...

Controller Algorithms for Single Feed Switched Parasitic Antennas (2006)

Thiel, David Victor

Controller Algorithms for Single Feed Switched Parasitic Antennas Elyas Palantei * (1), and David V. Thiel (1) (1) Centre for Wireless Monitoring & Applications (CWMA) Griffith University Nathan...

Optimizing piezo-resistive strain gauge characteristics for intelligent strain sensing applications (2005)

Macnamara, Dwain Seton, Thiel, David Victor, James, Daniel Arthur, Lisner, Peter Charles

This paper reviews current piezo-resistive characteristics pertaining to conventional and novel piezo-resistive strain transducers. These characteristics govern the performance of the sensor node. In...

Optical Electronics: RGB LED and the colours of the rainbow (2005)

Cameron, Aidan, Thiel, David Victor

Optical Electronics is an exciting and growing field of electronics. This activity will look at Red Green Blue (RGB) Light Emitting Diodes (LED). Optical Electronics is a great way of combining both...

Time-Dependent Surface Impedance from Sferics (2005)

O'Keefe, Yvette, Thiel, David Victor, O'Keefe, Steven Gregory

Attempts to use discrete sferics for low frequency impedance mapping have relied on Fourier analysis to derive time independent frequency profiles of the earth. A one dimensional transmission line...

Optimizing piezo-resistive strain gauge characteristics for intelligent strain sensing applications (2005)

Macnamara, Dwain Seton, Thiel, David Victor, James, Daniel Arthur, Lisner, Peter Charles

This paper reviews current piezo-resistive characteristics pertaining to conventional and novel piezo-resistive strain transducers. These characteristics govern the performance of the sensor node. In...

Optical Electronics: RGB LED and the colours of the rainbow (2005)

Cameron, Aidan, Thiel, David Victor

Optical Electronics is an exciting and growing field of electronics. This activity will look at Red Green Blue (RGB) Light Emitting Diodes (LED). Optical Electronics is a great way of combining both...

Time-Dependent Surface Impedance from Sferics (2005)

O'Keefe, Yvette, Thiel, David Victor, O'Keefe, Steven Gregory

Attempts to use discrete sferics for low frequency impedance mapping have relied on Fourier analysis to derive time independent frequency profiles of the earth. A one dimensional transmission line...

Wireless network topology for monitoring mobile agents (2005)

Fraser, Matthew James, James, Daniel Arthur, Thiel, David Victor

A wireless network of multiple sensor nodes for monitoring large numbers of mobile agents is described and investigated. Wireless monitoring provides time critical information from a number of data...

Modelling Yagi-Uda antennas using point source approximation (2004)

Ebersbach, Harald, Thiel, David Victor, Leckenby, M.

A point source approximation is shown to be an efficient algorithm for calculating the near and far fields of Yagi-Uda antennas for the evaluation of the human radiation exposure zone boundaries....

Switched parasitic antenna on a finite ground plane with conductive sleeve (2004)

Schlub, Robert Walter, Thiel, David Victor

A switched parasitic monopole antenna on a finite ground structure with a conductive sleeve attached to a small, circular ground plane controls the vertical radiation direction. The antenna was...

The surface impedance of a homogeneous TM-type plane wave at skew incidence upon an inclined anisotropic half-space (2004)

Wilson, Glenn Andrew, Thiel, David Victor

General expressions for the electromagnetic fields of homogeneous TM-type plane waves at a skew angle of incidence upon an inclined anisotropic half-space are derived. Previous analyses have only...

Modelling Yagi-Uda antennas using point source approximation (2004)

Ebersbach, Harald, Thiel, David Victor, Leckenby, M.

A point source approximation is shown to be an efficient algorithm for calculating the near and far fields of Yagi-Uda antennas for the evaluation of the human radiation exposure zone boundaries....

Switched parasitic antenna on a finite ground plane with conductive sleeve (2004)

Schlub, Robert Walter, Thiel, David Victor

A switched parasitic monopole antenna on a finite ground structure with a conductive sleeve attached to a small, circular ground plane controls the vertical radiation direction. The antenna was...

The surface impedance of a homogeneous TM-type plane wave at skew incidence upon an inclined anisotropic half-space (2004)

Wilson, Glenn Andrew, Thiel, David Victor

General expressions for the electromagnetic fields of homogeneous TM-type plane waves at a skew angle of incidence upon an inclined anisotropic half-space are derived. Previous analyses have only...

Two-dimensional finite-difference modeling of media with inclined uniaxial conductivity with an equivalent biaxial conductivity tensor for homogeneous TM-type wave propagation problems (2003)

Wilson, Glenn Andrew, Thiel, David Victor

The principle of numerically modeling the surface impedance of a homogeneous transverse magnetic (TM)-type plane wave incident upon an inhomogeneous half-space with inclined uniaxial electrical...

The equivalence of inclined uniaxial and biaxial electrical anisotrophy in inhomogeneous two-dimensional media for homogeneous TM-type plane wave propagation problems (2003)

Wilson, Glenn Andrew, Thiel, David Victor

For a homogeneous TM-type wave propagating in a two-dimensional half space with both vertical and horizontal inhomogeneities, where the TM-type wave is aligned with one of the elements of the...

Practical hot wire anemometerexcitation modes (2003)

Adamec, Richard, Thiel, David Victor, Tanner, Philip

The operation of a thin film hot wire directional anemometer is demonstrated using three modes of operation; constant voltage, constant current, constant resistance, and the heating response and...

MEMS Wind Direction Detection: From Design to Operation (2003)

Adamec, Richard, Thiel, David Victor, Tanner, Philip

A multi-axis hotwire anemometer fabricated with bulk micro-machining and thin film semiconductor technologies is presented. Extending the operation of a single axis anemometer into 2 axes allows...

MEMS Wind Direction Detection: From Design to Operation (2003)

Adamec, Richard, Thiel, David Victor, Tanner, Philip

A multi-axis hotwire anemometer fabricated with bulk micro-machining and thin film semiconductor technologies is presented. Extending the operation of a single axis anemometer into 2 axes allows...

Two-dimensional finite-difference modeling of media with inclined uniaxial conductivity with an equivalent biaxial conductivity tensor for homogeneous TM-type wave propagation problems (2003)

Wilson, Glenn Andrew, Thiel, David Victor

The principle of numerically modeling the surface impedance of a homogeneous transverse magnetic (TM)-type plane wave incident upon an inhomogeneous half-space with inclined uniaxial electrical...

The equivalence of inclined uniaxial and biaxial electrical anisotrophy in inhomogeneous two-dimensional media for homogeneous TM-type plane wave propagation problems (2003)

Wilson, Glenn Andrew, Thiel, David Victor

For a homogeneous TM-type wave propagating in a two-dimensional half space with both vertical and horizontal inhomogeneities, where the TM-type wave is aligned with one of the elements of the...

Practical hot wire anemometerexcitation modes (2003)

Adamec, Richard, Thiel, David Victor, Tanner, Philip

The operation of a thin film hot wire directional anemometer is demonstrated using three modes of operation; constant voltage, constant current, constant resistance, and the heating response and...

MEMS Wind Direction Detection: From Design to Operation (2003)

Adamec, Richard, Thiel, David Victor, Tanner, Philip

A multi-axis hotwire anemometer fabricated with bulk micro-machining and thin film semiconductor technologies is presented. Extending the operation of a single axis anemometer into 2 axes allows...

Full-wave analysis of choking charactertistics of sleeve balun on coaxial cables (2002)

Saario, Seppo, Lu, Junwei, Thiel, David Victor

An optimal design for a sleeve balun with maximum choking on a coaxial cable is determined using a full-wave body of revolution finite difference time domain method with perfectly matched layer...

FDTD analysis of dielectric-embedded electronically switched multiple-beam (DE-ESMB) antenna array (2002)

Lu, Junwei, Thiel, David Victor, Saario, Seppo

The design procedure, finite-difference time-domain (FDTD) modeling, and experimental measurements for a novel dielectric-embedded electronically switched multiple-beam (DE-ESMB) antenna array are...

Full-wave analysis of choking charactertistics of sleeve balun on coaxial cables (2002)

Saario, Seppo, Lu, Junwei, Thiel, David Victor

An optimal design for a sleeve balun with maximum choking on a coaxial cable is determined using a full-wave body of revolution finite difference time domain method with perfectly matched layer...

O2 plasma treated polyimide-based humidity sensors (2002)

Suzuki, Takeharu, Tanner, Philip, Thiel, David Victor

The effect of non-plasma and plasma treated polyimide-based humidity sensors is presented. Pure oxygen was used to etch polyimide in a plasma etcher. The sensor treated in a plasma exhibited higher...

FDTD analysis of dielectric-embedded electronically switched multiple-beam (DE-ESMB) antenna array (2002)

Lu, Junwei, Thiel, David Victor, Saario, Seppo

The design procedure, finite-difference time-domain (FDTD) modeling, and experimental measurements for a novel dielectric-embedded electronically switched multiple-beam (DE-ESMB) antenna array are...

Modeling of Inclined Anisotropic Complex Permittivity Media Using the Self-Consistent Impedance Method (2002)

Wilson, Glenn Andrew, Thiel, David Victor

The self-consistent impedance method has been shown to accurately model media with inclined, complex permittivity using the Euler rotation of the inverse complex permittivity tensor. The resultant...

Electronically Steerable Yagi-Uda Microstrip Patch Antenna Array (1995)

Gray, David, Lu, Junwei, Thiel, David Victor

Summary form only given. The article describes a four microstrip Yagi-Uda antenna array. The array consists of four Yagi-Uda antennas arranged around a common reflector patch. This array is...

Olfactory Imaging: An Electronic Nose Using Tiered Artifical Neural Networks and Quartz Piezoelectric Gas Sensors (1995)

Saunders, Bruce, Thiel, David Victor, Mackay-Sim, Alan

Our group is interested in the potential use of gas sensors for detection of key odorants in industry and as alternative sensory mechanisms for guidance control in robots. It has been recently shown...

Response Kinetics of Chemically Modified Piezoelectric Quatz Piezoelectric Crystals During Odorant Stimulation (1995)

Saunders, Bruce, Thiel, David Victor, Mackay-Sim, Alan

When chemically-modified piezoelectric quartz crystals are used to detect odorous compounds in air the maximum frequency changes induced by odorants vary both within and between sensors. This...

Odor sensing for robot guidance (1994)

Deveza, Reimundo, Thiel, David Victor, Russell, Andrew, Mackay-Sim, Alan

There is no generally applicable technique for finding the position of an autonomous mobile robot operating in an un structured or varying environment. This article describes a project to investigate...

Phase Change and Viscosity Effects on a Quartz Crystal Microbalance. (1994)

Busfield, Walter Kenneth, Bushell, Gillian Robin, James, Daniel Arthur, Mackay-Sim, Alan, Thiel, David Victor

The mass–frequency dependence for various materials deposited onto the surface of a resonating quartz crystal was investigated. The relationship is linear, but the constant of proportionality is...