Paul Record | Heriot-Watt University (original) (raw)
Papers by Paul Record
IEEE Transactions on Education, 2005
A virtual learning environment (VLE) to improve understanding of simple faul tfinding was created... more A virtual learning environment (VLE) to improve understanding of simple faul tfinding was created from a series of Web pages, an online quiz with automated marking, and a localarea-network-based simulator. It was tested on 57 first-year students (in 2002) and 69 students in 2003, taking a module in engineering design in electrical engineering in which a battery charger was designed and constructed. The results indicate that there was better than 100% improvement in the number of working battery chargers in both tested years. In addition, the students who used the VLE produced more working chargers and were better able to identify circuit blocks than those that did not. The learning approach is described by the adaptive character of thought cited in the present paper.
Journal of Medical Engineering & Technology, 1988
An electronically controlled micro-welding apparatus has been designed and built for the manufact... more An electronically controlled micro-welding apparatus has been designed and built for the manufacture of clinical electrodes. Using the principle of electrical resistance welding, the device is simple and inexpensive to construct, using readily available components. It is easy to operate and has proved to be a quick and reliable method of producing electrodes to the exact specifications of neurosurgeons.
Journal of Medical Engineering & Technology, 1989
Medical Engineering & Physics, 1996
In fIpctricaal impedance tomography, a single channel j&ilure i-auses distortion to the ouerall i... more In fIpctricaal impedance tomography, a single channel j&ilure i-auses distortion to the ouerall image. Mathematical mo&Uing and curu@ttinCg techniques were used to recover corrupted data. A single rhannel was disconnected in two experiments on a salin@led dish with one and two objects, respertively. Voltage gradient data were then qnthesizrd from the overall shape of the curve and reconstructed. Thp technique demonstrated a considerabk improvement in the image quality. We conclude that the technique can be adapted in applications where rhanndfailure can occur r~~gular[v yuch as neonatal monitoring. Copytight 0 1996 f&+&r Science Ltd for IPFTMR.
Medical & Biological Engineering & Computing, 1995
This paper describes a wideband dielectric resonator antenna with 30% fractional bandwidth, opera... more This paper describes a wideband dielectric resonator antenna with 30% fractional bandwidth, operating at 11 GHz. The structure consists of a hollow cylindrical dielectric pellet fed by individually switched excitation probes. The switched excitation pattern provides the antenna a radiation beam that can be moved through 360 degrees in the azimuth plane. Simulation and experimental results are presented to illustrate the advantages of this design.
IEEE Antennas and Wireless Propagation Letters, 2010
ABSTRACT
The design steps for a novel cylindrical electronic bandgap antenna in the X-band are given. Simu... more The design steps for a novel cylindrical electronic bandgap antenna in the X-band are given. Simulation results, based on a FDTD modeller are also presented as an aid to designing the physical antenna. The antenna demonstrated high directivity in the H-plane. Measurements on a prototype achieved 54% fractional bandwidth with an average gain of 8 dBi and 17.5 dB front to back ratio in the azimuthal plane.
Progress in Electromagnetics Research B, 2009
A novel dielectric cylindrical electronic bandgap antenna is presented and analysed using an in-h... more A novel dielectric cylindrical electronic bandgap antenna is presented and analysed using an in-house developed Finite-Difference-Time-Domain software simulator. The design steps and the simulations results of a geometrical parametric study are also presented and discussed, focusing on the design of antennas to operate in the X-band with high directivity patterns on the H-plane. Finally, the measurements results of a set of experiments carried out on a prototype showed very good agreement with simulations: 11% fractional bandwidth at 10 GHz and an average gain of 9.5 dBi are achieved in the impedance bandwidth with 13 dB front-to-back-ratio in the azimuthal plane.
A new class of hemispherical dielectric resonator antenna using mixed dielectric with beam agilit... more A new class of hemispherical dielectric resonator antenna using mixed dielectric with beam agility is presented. The design of the antenna was optimized by extensive numerical simulations with the HFSS, Ansoft package. The antenna resonates at 5.6 GHz, with a diameter of 26 mm and Sn of -15 dB. Varying the position of a regional dielectric discontinuity allows the principle radiation direction to be moved continuously through 360 degrees in the azimuth plane, with a vertical beam-width of 60 degrees. The size of this antenna makes it ideally suitable for hand held wireless communicators.
A new antenna is described using salt dissolved in water as the radiating element. Recently, it h... more A new antenna is described using salt dissolved in water as the radiating element. Recently, it has been reported by the radio amateur community that stimulating a column of salt water, with a salinity in excess on 70 parts per thousand (ppt), at HF frequencies (
Electronics Letters, 2006
ABSTRACT
Progress in Electromagnetics Research B, 2009
A comparative study using numerical models on the mutual coupling (MC) between two different hete... more A comparative study using numerical models on the mutual coupling (MC) between two different heterogeneous beam steering dielectric resonator antennas (DRAs) and an omni-directional dielectric resonator antenna (DRA) is presented in this paper. The mutual coupling was investigated by varying the separation between the antennas and manipulating the far field radiation pattern of each antenna. Several arrangements with element separation ranging from 0.1 to 0.5 free space wave length were investigated at the design frequency of 10 GHz. Different configurations contributed to different isolation levels. It was found that a significant isolation (< −15 dB) between an array of heterogeneous DRAs can be obtained even with antennas placed in close proximity (0.1 free space wavelength separation). It was also shown that the resonant frequency and return loss are most affected at settings where the direction of the main lobe of antenna A overlaps with the direction of the main lobe of antenna B. The expected inverse proportionality between 'd' (the separation between two antennas) and the level of MC was also demonstrated.
Progress in Electromagnetics Research-pier, 2007
This paper describes a steerable broadband dielectric antenna with 30% fractional bandwidth, oper... more This paper describes a steerable broadband dielectric antenna with 30% fractional bandwidth, operating at 11 GHz. The structure consists of a hollow cylindrical dielectric pellet of permittivity 6 fed by four probes. Two methods are described for beam forming: 1-Beam forming has been achieved by individually switching between excited probes. The switched excitation mechanism provides the antenna with a reconfigurable radiation beam that can be moved in the azimuth plane. 2-Variable phase excitation of several probes. Complete azimuth sweep was demonstrated by both methods, allowing any desired angle of beam directions. Simulation and experimental results are presented to illustrate the advantages of both designs.
Electronics Letters, 2007
... References 1 Long, S., McAllister, M., and Liang, S.: 'The resonant cylindrical diel... more ... References 1 Long, S., McAllister, M., and Liang, S.: 'The resonant cylindrical dielectric cavity antenna', IEEE Trans. Antennas Propag., 1983, 31, (3), pp. 406412 2 Kingsley, SP, and O'Keefe, SG: 'Beam steering and monopulse processing of probe-fed dielectric resonator ...
Electronics Letters, 2008
ABSTRACT
In this work, it is shown that dc voltages may be measured via a capacitive interface, provided t... more In this work, it is shown that dc voltages may be measured via a capacitive interface, provided that the capacitance between the measurement system and the dc voltage source being measured is nonlinearized. This nonlinearization is achieved by the addition of a nonlinear capacitor in series with the coupling capacitance. Two types of nonlinear capacitor are used-multilayer ceramics and varicap diodes. Currently available multilayer ceramics have a larger value than desired but prove the concept, while the small capacitance of the varicap diode allows measurement on real wires. Results show that over a low voltage range (−8 V to +8 V), the voltage on a conductor can be measured if the coupling capacitance between source and electrode is larger than 20 pF, which equates to an electrode length of 5 cm when wire compliant with MIL-W-81044-22 is used. Detection is performed by momentarily applying a voltage at a node within the measurement system, then measuring the time it takes for this voltage to decay to a threshold level-the capacitive nonlinearity causes this time delay to be dependent upon the dc input voltage whose value is being measured.
IEEE Transactions on Education, 2005
A virtual learning environment (VLE) to improve understanding of simple faul tfinding was created... more A virtual learning environment (VLE) to improve understanding of simple faul tfinding was created from a series of Web pages, an online quiz with automated marking, and a localarea-network-based simulator. It was tested on 57 first-year students (in 2002) and 69 students in 2003, taking a module in engineering design in electrical engineering in which a battery charger was designed and constructed. The results indicate that there was better than 100% improvement in the number of working battery chargers in both tested years. In addition, the students who used the VLE produced more working chargers and were better able to identify circuit blocks than those that did not. The learning approach is described by the adaptive character of thought cited in the present paper.
Journal of Medical Engineering & Technology, 1988
An electronically controlled micro-welding apparatus has been designed and built for the manufact... more An electronically controlled micro-welding apparatus has been designed and built for the manufacture of clinical electrodes. Using the principle of electrical resistance welding, the device is simple and inexpensive to construct, using readily available components. It is easy to operate and has proved to be a quick and reliable method of producing electrodes to the exact specifications of neurosurgeons.
Journal of Medical Engineering & Technology, 1989
Medical Engineering & Physics, 1996
In fIpctricaal impedance tomography, a single channel j&ilure i-auses distortion to the ouerall i... more In fIpctricaal impedance tomography, a single channel j&ilure i-auses distortion to the ouerall image. Mathematical mo&Uing and curu@ttinCg techniques were used to recover corrupted data. A single rhannel was disconnected in two experiments on a salin@led dish with one and two objects, respertively. Voltage gradient data were then qnthesizrd from the overall shape of the curve and reconstructed. Thp technique demonstrated a considerabk improvement in the image quality. We conclude that the technique can be adapted in applications where rhanndfailure can occur r~~gular[v yuch as neonatal monitoring. Copytight 0 1996 f&+&r Science Ltd for IPFTMR.
Medical & Biological Engineering & Computing, 1995
This paper describes a wideband dielectric resonator antenna with 30% fractional bandwidth, opera... more This paper describes a wideband dielectric resonator antenna with 30% fractional bandwidth, operating at 11 GHz. The structure consists of a hollow cylindrical dielectric pellet fed by individually switched excitation probes. The switched excitation pattern provides the antenna a radiation beam that can be moved through 360 degrees in the azimuth plane. Simulation and experimental results are presented to illustrate the advantages of this design.
IEEE Antennas and Wireless Propagation Letters, 2010
ABSTRACT
The design steps for a novel cylindrical electronic bandgap antenna in the X-band are given. Simu... more The design steps for a novel cylindrical electronic bandgap antenna in the X-band are given. Simulation results, based on a FDTD modeller are also presented as an aid to designing the physical antenna. The antenna demonstrated high directivity in the H-plane. Measurements on a prototype achieved 54% fractional bandwidth with an average gain of 8 dBi and 17.5 dB front to back ratio in the azimuthal plane.
Progress in Electromagnetics Research B, 2009
A novel dielectric cylindrical electronic bandgap antenna is presented and analysed using an in-h... more A novel dielectric cylindrical electronic bandgap antenna is presented and analysed using an in-house developed Finite-Difference-Time-Domain software simulator. The design steps and the simulations results of a geometrical parametric study are also presented and discussed, focusing on the design of antennas to operate in the X-band with high directivity patterns on the H-plane. Finally, the measurements results of a set of experiments carried out on a prototype showed very good agreement with simulations: 11% fractional bandwidth at 10 GHz and an average gain of 9.5 dBi are achieved in the impedance bandwidth with 13 dB front-to-back-ratio in the azimuthal plane.
A new class of hemispherical dielectric resonator antenna using mixed dielectric with beam agilit... more A new class of hemispherical dielectric resonator antenna using mixed dielectric with beam agility is presented. The design of the antenna was optimized by extensive numerical simulations with the HFSS, Ansoft package. The antenna resonates at 5.6 GHz, with a diameter of 26 mm and Sn of -15 dB. Varying the position of a regional dielectric discontinuity allows the principle radiation direction to be moved continuously through 360 degrees in the azimuth plane, with a vertical beam-width of 60 degrees. The size of this antenna makes it ideally suitable for hand held wireless communicators.
A new antenna is described using salt dissolved in water as the radiating element. Recently, it h... more A new antenna is described using salt dissolved in water as the radiating element. Recently, it has been reported by the radio amateur community that stimulating a column of salt water, with a salinity in excess on 70 parts per thousand (ppt), at HF frequencies (
Electronics Letters, 2006
ABSTRACT
Progress in Electromagnetics Research B, 2009
A comparative study using numerical models on the mutual coupling (MC) between two different hete... more A comparative study using numerical models on the mutual coupling (MC) between two different heterogeneous beam steering dielectric resonator antennas (DRAs) and an omni-directional dielectric resonator antenna (DRA) is presented in this paper. The mutual coupling was investigated by varying the separation between the antennas and manipulating the far field radiation pattern of each antenna. Several arrangements with element separation ranging from 0.1 to 0.5 free space wave length were investigated at the design frequency of 10 GHz. Different configurations contributed to different isolation levels. It was found that a significant isolation (< −15 dB) between an array of heterogeneous DRAs can be obtained even with antennas placed in close proximity (0.1 free space wavelength separation). It was also shown that the resonant frequency and return loss are most affected at settings where the direction of the main lobe of antenna A overlaps with the direction of the main lobe of antenna B. The expected inverse proportionality between 'd' (the separation between two antennas) and the level of MC was also demonstrated.
Progress in Electromagnetics Research-pier, 2007
This paper describes a steerable broadband dielectric antenna with 30% fractional bandwidth, oper... more This paper describes a steerable broadband dielectric antenna with 30% fractional bandwidth, operating at 11 GHz. The structure consists of a hollow cylindrical dielectric pellet of permittivity 6 fed by four probes. Two methods are described for beam forming: 1-Beam forming has been achieved by individually switching between excited probes. The switched excitation mechanism provides the antenna with a reconfigurable radiation beam that can be moved in the azimuth plane. 2-Variable phase excitation of several probes. Complete azimuth sweep was demonstrated by both methods, allowing any desired angle of beam directions. Simulation and experimental results are presented to illustrate the advantages of both designs.
Electronics Letters, 2007
... References 1 Long, S., McAllister, M., and Liang, S.: 'The resonant cylindrical diel... more ... References 1 Long, S., McAllister, M., and Liang, S.: 'The resonant cylindrical dielectric cavity antenna', IEEE Trans. Antennas Propag., 1983, 31, (3), pp. 406412 2 Kingsley, SP, and O'Keefe, SG: 'Beam steering and monopulse processing of probe-fed dielectric resonator ...
Electronics Letters, 2008
ABSTRACT
In this work, it is shown that dc voltages may be measured via a capacitive interface, provided t... more In this work, it is shown that dc voltages may be measured via a capacitive interface, provided that the capacitance between the measurement system and the dc voltage source being measured is nonlinearized. This nonlinearization is achieved by the addition of a nonlinear capacitor in series with the coupling capacitance. Two types of nonlinear capacitor are used-multilayer ceramics and varicap diodes. Currently available multilayer ceramics have a larger value than desired but prove the concept, while the small capacitance of the varicap diode allows measurement on real wires. Results show that over a low voltage range (−8 V to +8 V), the voltage on a conductor can be measured if the coupling capacitance between source and electrode is larger than 20 pF, which equates to an electrode length of 5 cm when wire compliant with MIL-W-81044-22 is used. Detection is performed by momentarily applying a voltage at a node within the measurement system, then measuring the time it takes for this voltage to decay to a threshold level-the capacitive nonlinearity causes this time delay to be dependent upon the dc input voltage whose value is being measured.