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Electromagnetics and Photonics

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Full-Text Articles in Electrical and Electronics

Calibration To Mitigate Near-Field Antennas Effects For A Mimo Radar Imaging System, Ha Hoang, Matthias John, Patrick Mcevoy, Max Ammann Jan 2020

Calibration To Mitigate Near-Field Antennas Effects For A Mimo Radar Imaging System, Ha Hoang, Matthias John, Patrick Mcevoy, Max Ammann

Articles

A calibration method for a high-resolution hybrid MIMO turntable radar imaging system is presented. A line of small metal spheres is employed as a test pattern in the calibration process to measure the position shift caused by undesired antenna effects. The unwanted effects in the antenna near-field responses are analysed, modelled and significantly mitigated based on the symmetry and differences in the responses of the MIMO configuration.


Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann Jan 2018

Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann

Articles

Full duplex radios have become a topic of increased interest in the wireless communications community. As part of this development, many efforts were directed to passively decrease the self-interference level at the antenna outputs. However, in many proposed solutions transmission and reception occur through different propagation channels. This paper demonstrates and quantifies the negative impact of channel differentiation on pivotal applications of full-duplex radio, such as cognitive radio. Antenna designs used for self-interference suppression in full-duplex radio architectures are analyzed. In order to ensure that transmission and reception occur within the same propagation channel, the use of the envelope correlation …


Pattern Reconfigurable Back-To-Back Microstrip Patch Antenna, Kansheng Yang, Xiulong Bao, Patrick Mcevoy, Max Ammann Oct 2016

Pattern Reconfigurable Back-To-Back Microstrip Patch Antenna, Kansheng Yang, Xiulong Bao, Patrick Mcevoy, Max Ammann

Articles

A back-to- back microstrip patch antenna with a switchable pattern is proposed for WLAN applications. The patch elements, printed on FR-4 substrates with a common ground plane, are switched with a single-pole double-throw PIN diode circuit. Switching the feed selects either of two identical radiation patterns in the opposing hemispheres for spatial diversity that would benefit a distributed network.


Amorphous Silicon Solar Vivaldi Antenna, Oisin O'Conchubhair, Kansheng Yang, Patrick Mcevoy, Max Ammann Mar 2016

Amorphous Silicon Solar Vivaldi Antenna, Oisin O'Conchubhair, Kansheng Yang, Patrick Mcevoy, Max Ammann

Articles

An ultra-wideband solar Vivaldi antenna is proposed. Cut from amorphous silicon cells, it maintains a peak power at 4.25 V which overcomes a need for lossy power management components. The wireless communications device can yield solar energy or function as a rectenna for dual-source energy harvesting. The solar Vivaldi performs with 0.5 - 2.8 dBi gain from 0.95 - 2.45 GHz and in rectenna mode, it covers three bands for wireless energy scavenging.


Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann Jul 2015

Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann

Articles

A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz).


Circularly Polarized Solar Antenna For Airborne Communication Nodes, Oisin O’Conchubhair, Adam Narbudowicz, Patrick Mcevoy, Max Ammann Apr 2015

Circularly Polarized Solar Antenna For Airborne Communication Nodes, Oisin O’Conchubhair, Adam Narbudowicz, Patrick Mcevoy, Max Ammann

Articles

A circularly polarized solar cell antenna consisting of four sequentially rotated printed inverted-F antennas is proposed. Four multicrystalline silicon solar cells act as the ground plane and the antenna is suitable for low power airborne communication nodes and wireless sensor networks. The antenna design was developed to allow 100% insolation of the cells when directly facing a light source. The low-profile antenna minimises shadowing of the solar cell for oblique angle insolation.


Integration Of Antenna Array With Multicrystalline Silicon Solar Cell, Oisin O'Conchubhair, Patrick Mcevoy, Max Ammann Feb 2015

Integration Of Antenna Array With Multicrystalline Silicon Solar Cell, Oisin O'Conchubhair, Patrick Mcevoy, Max Ammann

Articles

The integration of a low-profile antenna array with a multicrystalline silicon solar cell capable of powering a low-power wireless sensor at 2.45 GHz is reported. Lattice bus bars on the cell are exploited to minimize antenna shadows from low-profile antennas and transmission lines for a higher output power. The dual inverted-F array improves gain, and beam switching enables the array to sweep a wider coverage angle with larger beamwidths compared to other solar integrated antennas.


Contactless Measurement Of Angular Velocity Using Circularly Polarized Antennas, Vit Sipal, Adam Narbudowicz, Max Ammann Dec 2014

Contactless Measurement Of Angular Velocity Using Circularly Polarized Antennas, Vit Sipal, Adam Narbudowicz, Max Ammann

Articles

An innovative method to measure the angular velocity using circularly polarized antennas is proposed. Due to the properties of circular polarization, the angular velocity is frequency modulated (FM) on a wireless carrier. This enables a low-cost precise continuous measurement of angular velocity using a standard FM demodulator. The hardware can be easily adapted for both high and low angular velocity values. The precise alignment angle between the antennas can be determined if the initial antenna orientation is known. The angular error is shown to be


Impact Of Hub Location On The Performance Of Wireless Body Area Networks For Fitness Applications, Vit Sipal, Domenico Gaetano, Patrick Mcevoy, Max Ammann Dec 2014

Impact Of Hub Location On The Performance Of Wireless Body Area Networks For Fitness Applications, Vit Sipal, Domenico Gaetano, Patrick Mcevoy, Max Ammann

Articles

This letter compares the propagation properties of Wireless Body Area Networks for three different locations (head, foot and waist) of the hub/internet gateway on the human body. The wireless channels between the hubs and four nodes (chest, back, and upper arms) are measured on a female and a male subject performing push-ups and squats. A framework using spider plots is used for cumulative performance description. The results show that the best overall performance is for hub located on the left temple and the worst overall performance is achieved for a hub on the waist. These results are expected to stimulate …


Footwear And Wrist Communication Links Using 2.4 Ghz And Uwb Antennas, Domenico Gaetano, Patrick Mcevoy, Max Ammann, Colm Brannigan, Louise Keating, Frances Horgan Jun 2014

Footwear And Wrist Communication Links Using 2.4 Ghz And Uwb Antennas, Domenico Gaetano, Patrick Mcevoy, Max Ammann, Colm Brannigan, Louise Keating, Frances Horgan

Articles

It is reported that wearable electronic devices are to be used extensively in the next generation of sensors for sports and health monitoring. The information obtained from sensors on the human body depends on the biological parameters, the measurement rate and the number of sensors. The choice of the wireless protocol depends on the required data rates and on system configurations. The communication link quality is achieved with narrowband technologies such as Bluetooth or Zigbee, provided that the number of sensors is small and data rates are low. However, real-time measurements using wideband channels may also be necessary. This paper …


Footwear Antennas For Body Area Telemetry, Domenico Gaetano, Patrick Mcevoy, Max Ammann, Jacinta Browne, Louise Keating, Frances Horgan Oct 2013

Footwear Antennas For Body Area Telemetry, Domenico Gaetano, Patrick Mcevoy, Max Ammann, Jacinta Browne, Louise Keating, Frances Horgan

Articles

Antennas designed to link footwear sensors within body centric networks are introduced with two small UWB antennas, one directional and another quasi-omnidirectional. The radiating characteristics are evaluated for three positions on a sample sports shoe using a detailed simulation model and measurements with a homogenous foot phantom. Antenna performance is assessed for resilience to close proximity loading by the footwear materials and the phantom foot.


Antipodal Vivaldi Antenna For Water Pipe Sensor And Telemetry, Giuseppe Ruvio, Domenico Gaetano, Max Ammann, Patrick Mcevoy May 2012

Antipodal Vivaldi Antenna For Water Pipe Sensor And Telemetry, Giuseppe Ruvio, Domenico Gaetano, Max Ammann, Patrick Mcevoy

Articles

An antipodal Vivaldi antenna operates simultaneously for telemetry and sensing when placed conformally onto PVC pipes. Good radiation efficiency is realised and the antenna impedance matching remains stable when the pipe is empty or contains water. The Fidelity Factor performance based on an input Ultra Wideband Gaussian pulse is a suitable figure of merit to detect water presence. Different water levels and pipe conditions correspond to Fidelity Factors between 90% and 96%, which are a suitable dynamic range for sensing and the appropriate quality for pulse communications for remote monitoring.


Lead Silicate Glass Microsphere Resonators With Absorption-Limited Q, Pengfei Wang, Genapathy Murugan, Timothy Lee, Xian Feng, Yuliya Semenova, Qiang Wu, Wei Loh, Gilberto Brambilla, James Wilkinson, Gerald Farrell Jan 2011

Lead Silicate Glass Microsphere Resonators With Absorption-Limited Q, Pengfei Wang, Genapathy Murugan, Timothy Lee, Xian Feng, Yuliya Semenova, Qiang Wu, Wei Loh, Gilberto Brambilla, James Wilkinson, Gerald Farrell

Articles

We report the fabrication and characterization of a lead-silicate glass microsphere resonator. We show that at the wavelengths near 1555 nm high Q modes can be efficiently excited from a 109 μm diameter lead-silicate glass microsphere via evanescent coupling using a tapered silica fiber with a waist diameter of 2 μm. Resonances with Q-factors as high as 0.9×107 were observed. This is very close to the theoretical material-limited Q-factor and is the highest Q-factor reported so far from a nonlinear glass microsphere.


Microstrip-Fed Wideband Circularly Polarized Printed Antenna, Xiulong Bao, Max Ammann, Patrick Mcevoy Oct 2010

Microstrip-Fed Wideband Circularly Polarized Printed Antenna, Xiulong Bao, Max Ammann, Patrick Mcevoy

Articles

A wideband circularly-polarized printed antenna is proposed, which employs an asymmetrical dipole and a slit in the ground plane which are fed by an L-shaped microstrip feedline using a via. The proposed antenna geometry is arranged so that the orthogonal surface currents, which are generated in the dipole, feedline and ground plane, have the appropriate phase to provide circular polarization. A parametric study of the key parameters is made and the mechanism for circular polarization is described. The measured results show that the impedance bandwidth is approximately 1.34 GHz (2.45 GHz to 3.79 GHz) and the 3 dB axial ratio …


Macrobending Fiber Loss Filter, Ratiometric Wavelength Measurement And Application, Qian Wang, Ginu Rajan, Gerald Farrell, Pengfei Wang, Yuliya Semenova, Thomas Freir Jan 2007

Macrobending Fiber Loss Filter, Ratiometric Wavelength Measurement And Application, Qian Wang, Ginu Rajan, Gerald Farrell, Pengfei Wang, Yuliya Semenova, Thomas Freir

Articles

A macrobending standard single-mode fibre (SMF28) is optimized as an edge filter, with the optimal bending radius and length determined according to the bend loss and polarization sensitivity of the bending fibre. An all-fibre ratiometric wavelength system is built and calibrated. The system's accuracy and resolution is discussed with the influence of noise of input signal and photodetectors. Finally, the ratiometric system is employed for the demodulation of FBG strain sensing.