Research
Projects
Current Projects
The Fields of Portable Radios in an Indoor Environment
Portable radios such as cellular telephones, tablet computers, and walkie-talkies radiate electromagnetic fields for communication with their base station. In an indoor environment, the field is reflected from the walls, floor and ceiling, and scattered by objects in the room. An observer sees the “direct” field of the radio, which is the field in free space, and the “multipath” field, which is the sum of the fields associated with reflections and scattering. As the observer moves, the direct field and the multipath field go in and out of phase, leading to large fluctuations in the field strength over short distances, called “small scale fading” or “fast fading”.
In a hospital environment, the field strength due to a portable radio such as a cell phone or a tablet computer may exceed the immunity of a critical care medical device, causing it to malfunction. When several portable radios are present the risk of exceeding the immunity of a medical device is enhanced. Hospitals must adopt an “EMI Control Policy” to manage the use of portable radios, such that the risk of malfunction is kept below a safe level.
In this project two software tools have been developed to calculate the fields of a portable radio in an indoor environment. The first, called GO_3D, uses geometrical optics in a full three-dimensional vector implementation. Walls are modelled as layered structures accounting for the polarization and angle dependence of the reflection coefficients. The code inputs a detailed floor plan, the location of a transmitter and its frequency and antenna patterns, and the location of a grid of observers. The code uses the image-tree method to compute the field strength at each observer, accounting for reflections until the reflected field falls below a specified “threshold” level. The code predicts the detailed fast fading and can be used to assess whether the field strength exceeds the immunity of a medical device anywhere in a given “local area” of space. The method provides accurate results but is computer-intensive. The second code, called FINDEMI, uses the Sabine method from acoustics to calculate the mean value of the multipath field, and then models the fast fading with a Ricean probability distribution. The risk that the field strength in a given local area exceeds immunity is calculated. The method is very fast in execution. The accuracy depends on the underlying statistical model, and can be very good.
Two projects are currently in progress. In the first, the risk of exceeding the immunity of medical devices is estimated when there are one or two portable radios in a hospital ward, accounting for the probability that those radios will be close to or well separated from medical devices. A quantitative risk estimate is useful for assessing the effectiveness of various proposals for an EMI Control Policy, including the increase in risk when staff do not comply with the rules.
The second project investigates the accuracy of the ray-tracing model, and of the statistical model of fast fading, against measurements of the field strength. A validation of the geometrical optics method is sought. In one series of experiments a controlled environment is created in an anechoic chamber, with two walls and a door as reflecting surfaces, where the positions and electrical properties are well known. Good agreement is demonstrated between the measured and the geometrical-optics field strength over a region. The statistics of the field can then be studied. In another series of experiments, measurements of the field strength are made in hallways and rooms of a typical building. In this case the construction of the walls, floor and ceiling is not accurately known. Surfaces deviated from perfect flatness. The electrical properties of the materials are not well known. Point by point agreement with geometrical optics modelling cannot be obtained. The objective is to investigate the accuracy of the statistical model of fast fading based on ray tracing calculations against the statistics found by measurement in the real environment.
Publications
Tiago F. C. Leao, Vincent Mooney-Chopin, and Christopher W. Trueman, “Electromagnetic Characterization of a Gyproc Slab and of a Layered Wall by Measurement and 3D Geometrical Optics Simulation”, IEEE Antennas and Wireless Propagation Letters, Vol. 12, pages 1570-1573, 2013.
Tiago Freire Carneiro Leao, Vincent Mooney-Chopin, and Christopher W. Trueman, “Statistics of the Electric Field Strength in a Controlled Multipath Environment”, 2013 IEEE International Symposium on Antennas and Propagation and USNC-URSI National Radio Science Meeting in Orlando, Florida, USA, July 7-12, 2013.
T.F.C. Leao and C.W. Trueman, “Ray-Tracing Prediction of Fast Fading in an Indoor Environment and Validation by Measurement”, IEEE Canadian Conference on Electrical and Computer Engineering, Montreal, Quebec, Canada, April 29-May 2, 2012.
T.F.C. Leao and C.W. Trueman, “Small-Scale Fading Determination with a Ray-Tracing Model, and Statistics of the Field”, IEEE International Symposium on Antennas and Propagation, Chicago, IL, USA, July 8-13, 2012.
M. Ardavan, C.W. Trueman and K. Schmitt, “A Sabine-Rice Approximation for the Risk of Exceeding Immunity”, IEEE International Symposium on Antenna and Propagation, Spokane, Washington, July 3-8, 2011.
M. Ardavan, C.W. Trueman and K. Schmitt, “Ricean and Rayleigh Probability distribution Functions for Estimating Field distributions in Indoor Propagation”, 27th Annual Review of Progress in Applied Computational Electromagnetics (ACES), Williamsburg, Virginia, March 27 to 31, 2011.
M. Ardavan, K. Schmitt, and C.W. Trueman, “A
Preliminary Assessment of EMI Control Policies in Hospitals”, Symposium
on Antenna Technology and Applied Electromagnetics, Ottawa, July 5 - 9, 2010.
C.W. Trueman, D. Davis, and B. Segal, “Relating
the Path Loss Exponent to the Room Absorption”, Applied Computational
Electromagnetics Society Journal, Vol. 24, No. 4, pp. 361-367, August 2009.
C.W. Trueman, D. Davis, B. Segal and W. Muneer,
“Validation of Fast Site-Specific Mean-Value Models for Indoor Propagation”,
Applied Computational Electromagnetics Society Journal, Vol. 24, No. 3. pp.
312-323, June, 2009.
Christopher. W. Trueman, Sergio S. Muhlen,
and Bernard Segal, “Predicting Data Rate
Coverage Using the Sabine Method in Multiple-Source Hospitals Today and
Tomorrow”, Third International Symposium on Medical Information and
Communication Technologies
(ISMICT), Montreal, Canada, February 24-27, 2009.
Bernard Segal, Sergio Muhlen, Donald Davis,
Christopher. W. Trueman, “Decision-tree Helps Determine Need for ad-hoc Testing & Minimum Separations”,
31st Canadian Medical and Biological Engineering Conference,
C.W. Trueman, S.
Muhlen, D.
Wadah Muneer,
“Rician-K Factor Study for Temporal and Spatial Variations”, MASc thesis,
Department of Electrical and Computer Engineering, Concordia University,
December 2007.
C.W. Trueman, B. Segal and D. Davis, “EMC
Criteria in the Presence of Multiple RF sources in Reflective Environments”,
North American Radio Science Meeting - URSI 2007, reference number URSI703, Ottawa, July
22-26, 2007.
B. Segal,
C.W. Trueman and D. Davis “Current Electromagnetic Compatibility
Issues in Wireless Healthcare and Similarities in Aviation”, North American
Radio Science Meeting - URSI 2007, reference number URSI728, Ottawa, July 22-26, 2007.
D.
W. Muneer, I. Abdalla, D.
D. Davis, B.
Segal and C.W. Trueman, “Wireless Communication in Healthcare: Development of a
new Multi-Source Electromagnetic Compatibility Criterion”, Symposium on Antenna
Technology and Applied Electromagnetics (ANTEM), July 16-19, 2006,
I.E. Abdalla, B. Segal,
and C.W. Trueman, “Wireless Local Area Networks in Hospitals: Visualization and
Quantification of Electromagnetic Interference Risk”, IASTED
International Conference on Antennas, Radar, and Wave Propagation (ARP 2005),
Ibrahem Abdalla, Bernard Segal, and Christopher W. Trueman, “Indoor Propagation of Wireless LAN Signals in a Hospital Environment and Electromagnetic Compatibility Implications”, Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), July 20-23, 2004, Ottawa.
Ibrahem Abdalla,
Don Davis, Bernard Segal, and Christopher W. Trueman,
“Wireless-Local-Area-Network (WLAN) Deployment Issues in Hospitals: Capacity,
Coverage and Electromagnetic Compatibility”, Symposium on Antenna Technology
and Applied Electromagnetics (ANTEM),
J. Zhao, R. Paknys, C.W. Trueman, “Efficient Reflection and Transmission Dyad Multiplication for 3D Geometrical Optics,” IEEE Trans. On Vehicular Technology, Vol. 52, No. 5, pp. 1412-1414, September, 2003.
C.W. Trueman, “Three-Dimensional Geometrical Optics Code for Indoor Propagation”, Journal of the Applied Computational Electromagnetics Society (ACES), Vol. 17, No. 2, pp. 134-144, July, 2002.
D.
Bernard Segal, Don Davis, Christopher W. Trueman, and Tomas
J.F. Pavlasek, “Risk of patient injury due to electromagnetic-interference
malfunctions: Estimation and minimization,” 2001 IEEE EMC Symposium,
C.W. Trueman, D. Davis, and B. Segal, “Ray Optical Simulation of Indoor Corridor Propagation at 850 and 1900 MHz,” IEEE AP-S Conference on Antennas and Propagation for Wireless Communication, pp. 81-84, Waltham, Massachusetts, November 6-8, 2000.
D. Davis, B. Segal, C.W. Trueman, R. Calzadilla, and T. Pavlasek, “Measurement of Indoor Propagation at 850 MHz and 1.9 GHz in Hospital Corridors,” IEEE AP-S Conference on Antennas and Propagation for Wireless Communication, pp. 77-80, Waltham, Massachusetts, November 6-8, 2000.
Don Davis, Bernard Segal, David Chu, Christopher Trueman, and Tomas Pavlasek, “Effect of Spatial-Sampling Resolution on Electromagnetic Path-Loss and Interference-Potential Estimates in Hospital Corridors,” The Canadian Medical Biological Engineering Society, pp. 46-47, Halifax, Nova Scotia, October 26-28, 2000.
C.W. Trueman, D. Davis, and B. Segal, “Specifying Zones for Cellular Telephone Operation in Hospital Hallways,” Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), pp. 381-386, Winnipeg, Manitoba, July 30-August 2, 2000.
C.W. Trueman, R. Paknys, J. Zhao, D. Davis, and
B. Segal, “Ray Tracing Algorithm for Indoor Propagation,” ACES 16th
Annual Review of Progress in Applied Computational Electromagnetics, pp.
493-500, Monterey, California, March 20-24, 2000.
Junsheng Zhao, Robert
Paknys, and Christopher Trueman, “Three-Dimensional Model for Indoor Wave
Propagation Prediction,” Final Report,
Antennas using Carbon
Composite Materials
Carbon composite materials are now used extensively for the outer skin of an aircraft, to replace aluminum. Although carbon composite has excellent mechanical properties, the electrical conductivity is much less than that of aluminum. Working with the Concordia Center for Composites, samples of composite material were made and tested for shielding effectiveness over a wide frequency range. Anisotropic behavior was investigated for composites based on carbon-fibre material. Increases in conductivity were obtained using multiwall carbon nanotubes. The project expanded to include the design of antennas using composite material, including ultra-wideband antennas and fractal antennas for multiband applications. The Green’s Function of carbon composite was found. The orientation of the carbon fibres used to make the composite can yield a material with anisotropic conductivity, and anisotropy can be taken advantage of to make antennas special properties. The performance of a patch antenna is changed by the orientation of the fibres in a carbon composite ground plane. An antenna with reconfigurable properties was made with a rotatable anisotropic ground plane. PhD student Aidin Mehdipour’s thesis on composites won the Concordia University Distinguished Doctoral Dissertation Prize in Engineering in 2012 and the Governor General Gold Medal Award, Technology, Industry and the Environment in
2011. I co-supervised Aidin with Dr. A-R Sebak.
Publications
A.Mehdipour, T. A. Denidni, A.-R. Sebak, C. W. Trueman, I. D. Rosca, and S. V. Hoa, “Mechanically Reconfigurable Antennas Using an Anisotropic Carbon-Fiber Composite Ground”, IET Microwaves, Antennas & Propagation Journal, Vol. 7, No. 13, pp. 1055-1063, 2013.
Aidin Mehdipour, Tayeb Denidni, Abdel Sebak, Christopher Trueman, Iosif Rosca, and Suong Hoa, “Anisotropic Carbon Fiber Nanocomposites for Mechanically Reconfigurable Antenna Applications”, 2013 IEEE International Symposium on Antennas and Propagation and USNC-URSI National Radio Science Meeting in Orlando, Florida, USA, July 7-12, 2013.
A.Mehdipour, A. Sebak, C. Trueman, T. Denidni, "Compact Multiband Planar Antenna for 2.4/3.5/5.2/5.8 GHz Wireless Applications," IEEE Antennas and Wireless Propagation Letters, Volume 11, pp. 144-147, 2012.
A.Mehidpour, A. R. Sebak, C.W. Trueman, I.D. Rosca and S.V Hoa, “Advanced Conductive Carbon Fiber Composite Materials for Antenna and Microwave Applications”, IEEE International Symposium on Antennas and Propagation, Chicago, IL, USA, July 8-13, 2012.
Aidin Mehdipour, Abdel-Razik Sebak and Christopher W. Trueman, "Green’s Function of a Dielectric Slab Grounded by Carbon Fiber Composite Materials" IEEE Transactions on Electromagnetic Compatibility, Vol. 54, No. 1, pp. 118-124, February, 2012.
Aidin Mehdipour, Iosif D. Rosca, Christopher W. Trueman, Abdel-Razik Sebak, and Suong. V. Hoa, "Multiwall Carbon Nanotube - Epoxy Composites with High Shielding Effectiveness for Aeronautic Applications" IEEE Transactions on Electromagnetic Compatibility, Vol. 54. No. 1, pp. 28-35, Feb. 2012.
Aidin Mehdipour, Iosif D. Rosca , Abdel-Razik Sebak, Christopher W. Trueman, and Suong. V. Hoa, “Carbon Nanotube Composites for Wideband Millimeter-Wave Antenna Applications”, IEEE Trans on Antennas and Propagation, Vol. 59, No. 10, pp. 3572-3578, October 2011.
Aidin Mehdipour, Abdel-Razik Sebak, Christopher W. Trueman, Iosif D. Rosca, and Suong V. Hoa, “Performance of Microstrip Patch Antenna on a Reinforced Carbon Fibre Composite Ground Plane,” Microwave and Optical Technology Letters. Vol. 53, No. 6, pp. 1328-1331, June, 2011.
Aidin Mehdipour, “Advanced Carbon Fiber Composite Materials for Shielding and Antenna Applications”, PhD thesis, Department of Electrical and Computer Engineering, Concordia University, May 2011.
A. Mehdipour, I.D. Rosca, A-R Sebak, and C.W. Trueman, “Full Composite Fractal Antenna using Carbon Nanotubes for Multiband Wireless Applications”, IEEE Antennas and Wireless Propagation Letters, pp. 891-894, Vol. 9, 2010.
A. Mehdipour, A.-R. Sebak, C. W. Trueman, I. D. Rosca, and S. V. Hoa, “Reinforced continuous carbon-fiber composites using multi-wall carbon nanotubes for wideband antenna applications,” IEEE Trans. Antennas Propag., Vol. 58, No. 7, pp. 2451-2456, July, 2010.
A. Mehdipour, I.D. Rosca , A-R Sebak, C.W. Trueman, and S.V. Hoa, “Carbon-Fiber Nanotubes for X-Band Conformal Antenna Applications”, IEEE International Symposium on Antenna and Propagation Symposium, Toronto, Ontario, July 11-17, 2010.
A. Mehdipour, I. D. Rosca, A.-R. Sebak, C. W. Trueman, and S. V. Hoa, “Advanced carbon-fiber composite materials for RFID tag antenna applications”, Applied Computational Electromagnetic Society (ACES) Journal - Special Issue on Computational and Experimental Techniques for RFID Systems and Applications, Vol. 25, No. 3, pp. 218-229, March 2010.
A. Mehdipour, I. D. Rosca, C. W. Trueman, A. R. Sebak, and S. V. Hoa, “Shielding effectiveness analysis of reinforced continuous carbon fiber (RCCF) composites: numerical and experimental study,” The 1st Canadian and American Technical Conference on Composites (ASC/CACSMA), University of Delaware, Newark, Delaware, Sept. 15-17, 2009.
A. Mehdipour, I. D. Rosca, C. W. Trueman, A. R. Sebak, and S. V. Hoa, “High frequency shielding properties of multiwall carbon nanotube (MWCNT) composites” The 1st Canadian and American Technical Conference on Composites (ASC/CACSMA), University of Delaware, Newark, Delaware, Sept. 15-17, 2009.
A. Mehdipour, A.-R. Sebak and C. W. Trueman, and S. V. Hoa, “Carbon-Fiber composite T-match folded bow-tie antenna for RFID applications,” IEEE Antenna and Propagation Symposium (APS 2009), Charleston, SC, June 1-5, 2009.
A. Mehdipour, A.-R. Sebak and C. W. Trueman, “Compact microstrip-fed antenna for 2.4/5.2/5.8 GHz wireless communication systems,” IEEE Antenna and Propagation Symposium (APS 2009), Charleston, SC, June 1-5, 2009.
A. Mehdipour, A. Parsa, A.-R. Sebak and C. W. Trueman, “Miniaturized CPW-fed antenna and band-notched design for UWB applications”, IET Microw. Antennas and Propag, vol. 3, Iss. 6, pp. 974-986, 2009.
A. Mehdipour, C. W. Trueman, A. R. Sebak, I. D. Rosca and S. V. Hoa, “Shielding effectiveness analysis of multilayer carbon-fiber composite materials” General Assembly of the International Union of Radio Science (URSI 2008), Chicago, USA, August 7-16, 2008.
A. Mehdipour*, A. R. Sebak, and C. W. Trueman, “A Novel Ultrawideband Slot-Antenna with Dual Band-Notched Characteristics”, IEEE International Symposium on Antennas and Propagagtion, San Diego, July 5-11, 2008.
A. Mehdipour, A. Parsa, A. R. Sebak, and C. W. Trueman, “Planar Bell-Shaped Antenna Fed by a CPW for UWB Applications”, IEEE International Symposium on Antennas and Propagagtion, San Diego, July 5-11, 2008.
Ibrahem Abdalla, Tanaz Rahimzadeh, Christopher W. Trueman, and Suong V.
Hoa, “Shielding Effectiveness and Electrical Conductivity of Carbon/Epoxy
Composites”, Society for the Advancement of Material and Process Engineering
(SAMPE) Symposium 2006, Long Beach, California, April 30-May 6, 2006.
Past Projects
Unconditionally-Stable Finite Difference Time Domain Methods
The speed of travel of an electromagnetic wave in Yee’s Finite-Difference Time-Domain (FDTD) method is dependent on the direction of travel. This has many implications, such as affecting the resonant frequencies of objects modelled with FDTD. From 2001 to 2007 I worked on implicit FDTD formulations with PhD student Guilin Sun. We published eleven papers, listed below. These papers provide a variety of choices for designing an FDTD formulation for a given problem, allowing trade-offs between dispersion accuracy, time step, and execution speed.
Publications
Guilin Sun and C.W. Trueman, “Efficient Implementations of the Crank-Nicolson Scheme for the Finite-Difference Time-Domain Method”, IEEE Trans. on Microwave Theory and Techniques, Vol. 54, No. 5, pp. 2275-2284, May, 2006.
Guilin Sun and C.W. Trueman, “Suppression of Numerical Anisotropy and Dispersion with Optimized Finite-Difference Time-Domain Methods", IEEE Trans. On Antennas and Propagation, Vol. 53, No. 12, pp. 4121-4128, December 2005.
Guilin Sun and C.W. Trueman, "Numerical Dispersion and Numerical Loss in Explicit Finite-Difference Time-Domain Methods in Lossy Media,” IEEE Trans. on Antennas and Propagation, Vol. 53, No. 11, pp. 3684-3690, November, 2005.
Guilin Sun, “Development and Evaluation of Novel Finite-Difference Time-Domain Methods for Solving Maxwell’s Equations”, PhD thesis, Department of Electrical and Computer Engineering, Concordia University, March, 2005.
G. Sun and C.W. Trueman, “Optimized Finite-Difference Time-Domain Methods Based on the (2,4) Stencil”, IEEE Transactions on Microwave Theory and Techniques, Vol. 53, No. 3, pp. 832-842, March, 2005.
Guilin Sun and Christopher W. Trueman, “Approximate Crank-Nicolson Schemes for the 2D Finite-Difference Time-Domain Method for TEz Waves”, IEEE Transactions on Antennas and Propagation, Vol. 52, No. 11, pp. 2963-2972, November, 2004.
G. Sun and C.W. Trueman, “Numerical Validation of Dispersion Relations Using a Cylindrical Wave for 2D FDTD Methods”, Microwave and Optical Technology Letters, Vol. 43, No. 2, pp. 138-142, October 20, 2004. (SCI)
Guilin Sun and Christopher W. Trueman, “An Unconditionally-Stable FDTD Method Based on the Crank-Nicolson Scheme for Solving the Three-Dimensional Maxwell’s Equations”, IEE Electronics Letters, Vol. 40, No. 10, pp. 2589-590, 13 May 2004. (SCI)
G. Sun and C.W. Trueman, “A Simple Method to Determine the Time-Step Size to Achieve a Desired Dispersion Accuracy in ADI-FDTD”, Microwave and Optical Technology Letters, Vol. 40, No. 6, pp. 487-490, March 20, 2004. (SCI)
G. Sun and C.W. Trueman, “Some Fundamental Characteristics of the One-Dimensional Alternate-Direction-Implicit Finite-Difference Time-Domain Method”, IEEE Trans. on Microwave Theory and Techniques, Vol. 52, No. 1, pp. 46-52, January, 2004.
G. Sun and C.W. Trueman, “Accuracy of Three Unconditionally-Stable FDTD Schemes for Solving Maxwell’s Equations”, Journal of the Applied Computational Electromagnetics Society (ACES), Vol. 18, No. 4, pp. 41-47, November, 2003.
G. Sun and C.W. Trueman, “Analysis and Numerical Experiments on the Numerical Dispersion of Two-Dimensional ADI-FDTD”, IEEE Antennas and Wireless Propagation Letters, Vol. 2, No. 5, pp. 78-81, July, 2003.
G. Sun and C.W.
Trueman, “Unconditionally Stable Crank-Nicholson Scheme for Solving the
Two-Dimensional Maxwell's Equations”, IEE Electronics Letters, Vol. 39, No. 7,
pp. 595-597,
Radar Cross-Section of Ships and Missiles
At HF frequencies the size of an aircraft is comparable to the wavelength and the radar cross-section can vary rapidly with frequency when the airframe is resonant. In this project numerical computation was used to calculate the radar cross-section of a variety of aircraft. Measurements were done with the collaboration of the David Florida Laboratory, and excellent agreement was found between moment method computations, FDTD computations, and measurements.
At GHz frequencies aircraft and ships are electrically large and the radar cross-section can be dominated by scattering from individual parts of the structure. For example, ship targets contain dihedral and trihedral corner-reflector geometries. The RCS can be calculated efficiently by a combination of geometrical optics to trace rays through one or two reflections to determine the excitation of bulkheads in the ship geometry, and physical optics to calculate the scattered fields from those surfaces. Drs. Trueman and Paknys developed a geometrical-optics/physical-optics computer code called RPO capable of calculating the RCS of ships and aircraft. Scattering can be suppressed by coating surfaces with absorbent materials.
Publications
R. Paknys, C.W. Trueman, A. Ozturk, and A.
Altintas, “High Frequency RCS Prediction
for Vehicles Treated with RAM, Final
Contract Report, Contract Number W7707-010074/001/HAL, prepared for Defence
R&D – Atlantic, September 10, 2007.
C.W. Trueman and
R. Paknys, “RPO Version 1R”, Defence R&D Canada—
C.W. Trueman and
R. Paknys, “RPO Version 1Q”, Defence R&D Canada—
R. Paknys and
C.W. Trueman, “High Frequency RCS Prediction for Vehicles Treated with RAM”,
Defence R&D Canada—
R. Paknys and
C.W. Trueman, “High-Frequency RCS Prediction for Vehicles Treated with RAM”,
Quarterly Contract Report prepared for Defence R&D Canada-Atlantic,
Contract Number W7707-010074/001/HAL, January 15, 2004.
Q.C. Luu, C.W.
Trueman and S.J. Kubina, “Computations of Radar Cross Sections of TBMs at HF
Using Numerical Electromagnetics Codes (NEC),” Final Report, DND/DREO Contract
No. W7714-6-0057/001/SV, Technical Note TN-EMC-97-02, Dept. of Electrical and Computer Engineering,
Concordia University, August 31, 1997, 38 pages.
C.W. Trueman and
S.J. Kubina, "HF Ground Wave Radar Studies," Final Report, DSS/DREO
Contract No. W7714-3-9707/01-SV, Technical Note TN-EMC-94-02, Dept. of
Electrical and Computer Engineering, Concordia University, August 1994, 75
pages.
C.W. Trueman and
S.J. Kubina, "The Radar Cross-Section of Aircraft, Ships and Missiles at
HF Frequencies," Final Report, DOC/CRC Contract No. W7714-9-9216/01-SZ,
Technical Note TN-EMC-92-06, Dept. of Electrical and Computer Engineering,
Concordia University, Sept. 15, 1992, 332 pages.
C.W. Trueman and
S.J. Kubina, "The Calculation of Radar Cross-Section in the HF Band by
Wire Grid Modeling," Final Report, DOC/CRC Contract No. W7714-8-5654,
Technical Note TN-EMC-90-01, Dept. of Electrical and Computer Engineering,
Concordia University, April 30, 1990, 256 pages.
Ryan C. Solomon, Hank Leong, C.W. Trueman and
Yahia M.M Antar, “The Impact of Vertical Structures on Ship Radar Cross
Section in the High Frequency Range”,
Applied Computational
Electromagnetics Society Journal,
Vol. 24, No. 4, pp 407-412, August 2009.
C.W. Trueman,
S.J. Kubina, S.R. Mishra, and C. Larose, "Radar Cross-Section of a Generic
Aircraft at HF Frequencies," Canadian Journal of Electrical and Computer
Engineering, Vol. 18, No. 2, pp. 59-64, April 1993.
S.R. Mishra, C.L.
Larose, and C.W. Trueman, "Precision Radar Cross-Section Measurements for
Computer Code Validation," IEEE Trans. on Instrumentation and Measurement,
Vol. 42, No. 2, pp. 179-185, April 1993.
C.W. Trueman,
S.J. Kubina, S.R. Mishra, and C. Larose, "RCS of Resonant Scatterers with
Attached Wires," IEEE Trans. on Antennas and Propagation, Vol. 41, No. 3,
pp. 351-355, March 1993.
C.W. Trueman,
S.J. Kubina, S.R. Mishra, and C. Larose,
"RCS of Four Fuselage-Like Scatterers at HF Frequencies," IEEE
Trans. on Antennas and Propagation, Vol. AP-40, No. 2, pp. 236-240, February
1992.
C.W. Trueman,
S.J. Kubina, R.J. Luebbers, S.R. Mishra, and C.L. Larose, "RCS of
Dielectric Cubes and Rods by FDTD and by Measurement," Symposium on
Antenna Technology and Applied Electromagnetics, University of Manitoba,
Winnipeg,
S.R.
Mishra and C.W. Trueman, “Accuracy of RCS Measurements,” 18th AMTA
Annual Meeting and Symposium, Seattle, Washington, Sept. 30-
C.L. Larose, S.R.
Mishra, and C.W. Trueman, "A Database of Measured and Computed RCS for
Code Validation," Journées Internationales de Nice sur les Antennes
(JINA), Nice, France, Nov. 8-10, 1994.
C.W. Trueman,
S.J. Kubina, S.R. Mishra, and C.L. Larose, "HF RCS of Small Aircraft by
Computation and by Measurement," Journées Internationales de Nice sur les
Antennes (JINA), Nice, France, Nov. 8-10, 1994.
S.R. Mishra, C.L.
Larose, M. Flynn, and C.W. Trueman, "A Database Program for Organization,
Presentation and Distribution of Measured Antenna and RCS Pattern Data,"
16th Meeting and Symposium, Antenna Measurement Techniques
Association,
C.W. Trueman, S.J. Kubina, S.R. Mishra, and C.L.
Larose, "RCS of Small Aircraft at HF Frequencies," Symposium on
Antenna Technology and Applied Electromagnetics (ANTEM), pp. 151-157,
S.R. Mishra, C.L.
Larose, M. Flynn, and C.W. Trueman, "A Database of Measured Data for RCS
Code Validation," ACES 10th Annual Review of Progress in
Applied Computational Electromagnetics, Monterey, California, March 21-26,
1994.
C.W. Trueman,
R.J. Luebbers, S.R. Mishra, and C. Larose, "RCS of High Permittivity Cubes
Computed by FDTD with Prony Extrapolation," Third International Conference
on Electromagnetics in Aerospace Applications,
C.W. Trueman,
R.J. Luebbers, S.R. Mishra, and C. Larose, "FDTD Computation of the RCS of
High Permittivity Cubes," 1993 IEEE Antennas and Propagation Symposium,
Ann Arbor, Michigan, June 27-July 2, 1993.
C.W. Trueman,
S.J. Kubina, R.J. Luebbers, S.R. Mishra, and C. Larose, "RCS of High
Permittivity Cubes by FDTD and by Measurement," ACES 9th Annual
Review of Progress in Applied Computational Electromagnetics, Monterey,
California, March 22-26, 1993.
S.R. Mishra, C.
Larose, C.W. Trueman, and S.J. Kubina, "Scattering Patterns of Canonical
Targets and Their Use in RCS Analysis and Code Validation," International
Symposium on Antennas, Nice,
S.R. Mishra, C.L.
Larose, C.W. Trueman, and S.J. Kubina, "Measured and Computed RCS of
Generic Aircraft-Like Targets," 1992 Antenna Measurement Techniques
Association Symposium, pp. 2-19 to 2-24, Columbus, Ohio, Oct. 19-23, 1992.
C.W. Trueman,
S.J. Kubina, R.J. Luebbers, S.R. Mishra, and C.L. Larose, "RCS of
Dielectric Cubes and Rods by FDTD and by Measurement," Symposium on
Antenna Technology and Applied Electromagnetics, University of Manitoba,
Winnipeg,
C.W. Trueman,
S.J. Kubina, R.J. Luebbers, K.S. Kunz, S.R. Mishra, and C.L. Larose,
"Validation of FDTD RCS Computations for PEC Targets," 1992 IEEE
Antennas and Propagation Symposium, Chicago, Illinois, July 18-25, 1992.
S.R. Mishra, C.L.
Larose, C.W. Trueman, and S.J. Kubina, "Precision Radar Cross-Section
Measurements for Computer Code Validation," Conference on Precision
Electromagnetic Measurements, Paris, France,
C.W. Trueman,
S.J. Kubina, R.J. Luebbers, K.S. Kunz, S.R. Mishra, and C.L. Larose, "RCS
of Cubes, Strips, Rods and Cylinders by FDTD," ACES 8th Annual Review of Progress in Applied
Computational Electromagnetics, Monterey, California, March 16-20, 1992.
S.R. Mishra, C.W.
Trueman, and T. Coyne, "Surface-Wave Radar Cross-Section
Measurements," Antenna Measurement Techniques Association Symposium,
S.R. Mishra, C.L.
Larose, and C.W. Trueman, "Radar Cross-Section Measurement for Computer
Code Validation," 1991 Antenna Measurement Techniques Association
Symposium, Boulder, Colorado,
C.W. Trueman,
S.J. Kubina, S.R. Mishra, and C. Larose, "RCS of Ships and Aircraft at HF
Frequencies," Canadian Conference on Electrical and Computer Engineering,
C.W. Trueman,
S.J. Kubina, and S.R. Mishra, "RCS of Resonant Scatterers with Attached
Wires," 1991 IEEE International Symposium on Antennas and Propagation,
London, Ontario,
C.W. Trueman and
S.J. Kubina, "RCS of Fundamental Scatterers in the HF Band," ACES 7th
Annual Review of Progress in Applied Computational Electromagnetics, Monterey,
California, March 18-22, 1991.
C.W. Trueman and
S.J. Kubina, "RCS of Fundamental Scatterers in the HF Band by Wire-Grid
Modeling," Canadian Conference on Electrical and Computer Engineering,
Ottawa,
Handheld Radios and the Human Head and Hand
This project studied the interaction between a handheld radio such as a cellular telephone and the human head and hand. The far field is of interest to evaluate the pattern coverage of the radio. The far fields are determined by the design of the handset itself, but they are strongly influenced by the head and hand of the operator, and as the operator holds the radio at various angles and various distances to the head. The near field is of interest to evaluate the field strengths around the head and inside the head.
The human head and body behave electrically as high-permittivity, lossy dielectrics. The head and body have a complex internal structure consisting of many different tissue types, each with its own permittivity and conductivity. Further, the electrical parameters of human tissue vary with frequency. The finite-difference time-domain method is used to compute the field strengths inside and around the head as a function of time, due to a sinusoidal generator that gradually turns on.
This project included the validation of the computational model against measurements of the near field and the far fields of a portable radio operating near a model of the human head. The initial validation studies used a box or a sphere filled with liquid with the electrical parameters of brain tissue at the frequency of interest. Subsequently, a realistic three-dimensional model of the head called a "phantom" was used for the measurements. The head phantom included brain, bone, muscle, eye and skin tissue with the electrical parameters of real biological materials.
This research was funded by the Communications Research Centre of the Industry Canada and by the National Sciences and Engineering Research Council of Canada.
Publications
C.W. Trueman, S.J. Kubina, J.E. Roy and W.R. Lauber, “Radiation Patterns of a Portable Radio Handset with Simple Head Models,” Canadian Journal of Electrical and Computer Engineering, Vol. 26, No. 2, pp. 65-73, April 2001.
C.W. Trueman, S.J. Kubina, D. Cule, and W. Lauber, “Near Fields of a Portable Radio in Front of and on the Far Side of a Model of the Head,” Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), pp. 65-70, Winnipeg, Manitoba, July 30-August 2, 2000.
C.W. Trueman, S.J. Kubina, D. Cule and W.R. Lauber, "Validation of the FDTD Near Fields of a Portable Radio Handset and a Simple Head", Conference Proceedings, 15th Annual Review of Progress of the Applied Computational Electromagnetics Society, pp. 660-667, Monterey, California, March 16-28, 1999.
C.W. Trueman, S.J. Kubina, J.E. Roy and W.R. Lauber, "Validation of FDTD Handset and Head Patterns by Measurement", 1998 IEEE APS Conference on Antennas and Propagation for Wireless Communications, Watham, Mass., Nov. 1-4, 1998.
C.W. Trueman, S.J. Kubina, J.E. Roy and W.R. Lauber, "Portable Radio Handset Patterns in the Presence of a Model of the Head", Symposium on Antenna Technology and Applied Electromagnetics, Ottawa, August 9-12, 1998.
C.W. Trueman, S.J. Kubina, J.E. Roy, W.R. Lauber, and M. Vall-llossera, "Validation of FDTD-Computed Handset Patterns by Measurement", Conference Proceedings, 14th Annual Review of Progress of the Applied Computational Electromagnetics Society, pp. 93-98, Monterey, California, March 16-20, 1998.
C.W. Trueman, D. Rensburg, S.J. Kubina, M. Danesh, and S.R. Mishra, "Validation of Computed Portable Radio Handset Near Fields by Measurement", Symposium on Antenna Technology and Applied Electromagnetics (ANTEM '96), August 6-9, 1996, Montreal.
C.W. Trueman and S.J. Kubina, “Fields of an Analog
Cell Phone with a Hands-Free Kit Adapter”, Final Report, CRC Contract No.
8000497, Technical Note TN-EMC-02-02, Dept. of Electrical and Computer Engineering,
C.W. Trueman and S.J. Kubina, “Absorption of Power
in Head Models at Cellular and PCS Frequencies, Part A – EM Field Modeling and
Validation,” Final Report, CRC Contract No. U6800-0-0249, Technical Note
TN-EMC-01-01, Dept. of Electrical and Computer Engineering,
C.W. Trueman and S.J. Kubina, “Absorption of Power
in Head Models at Cellular and PCS Frequencies, Part B – Distribution of Power
Inside the Phantom Head,” Final Report, CRC Contract No. U6800-0-0249,
Technical Note TN-EMC-01-01, Dept. of Electrical and Computer Engineering,
C.W. Trueman and S.J. Kubina, “Modelling of
Electromagnetic Fields from Cellular Handsets and Human Head Models,” Final
Report, CRC Contract No. U6800-9-3324, Technical Note TN-EMC-00-01, Dept. of
Electrical and Computer Engineering,
C.W. Trueman and S.J. Kubina, “Near Field Computations with Model Heads and Far Field Computations for the Model Cellular Radio," Final Report, CRC Contract No. U6800-9-0390, Technical Note TN-EMC-99-01, Dept. of Electrical and Computer Engineering, Concordia University, March 31, 1999, 207 pages.
C.W. Trueman and S.J. Kubina, “A Research Study on Electromagnetic (EM) Fields Produced by Portable Transceivers,” Final Report, CRC Contract No. U68000-7-0726/001/ST, Technical Note TN-EMC-98-01, Dept. of Electrical and Computer Engineering, Concordia University, March 31, 1998, 168 pages.
C.W. Trueman, S.J. Kubina, D. Gaudine, and B. Lorkovic, “A Research Study on Electromagnetic Fields Produced by Portable Transceivers,” Final Report, PWGSC/CRC Contract No. U68000-6-0755/001/ST, Technical Note TN-EMC-97-01, Dept. of Electrical and Computer Engineering, Concordia University, March 31, 1997, 126 pages.
C.W. Trueman, S.J. Kubina and M. Danesh, “Fields of a Portable Radio Handset Near the Human Head,” Final Report, PWGSC/CRC Contract No. 67CRC-5-0850/01-ST, Technical Note TN-EMC-96-01, Dept. of Electrical and Computer Engineering, Concordia University, March 31, 1996, 149 pages.
C.W. Trueman and S.J. Kubina, "Characteristics of Electromagnetic Fields Produced by Portable Handheld Transceivers," Final Report, PWGSC/CRC Contract No. 36001-4-0395/01-ST, Technical Note TN-EMC-95-01, Dept. of Electrical and Computer Engineering, Concordia University, March 31, 1995, 137 pages.
S.J. Kubina and C.W. Trueman, "Computational Studies for Prediction of Energy Deposition in Humans Exposed to RF Fields from Cellular Phones," Final Report, Contract No. MIST/CRC 36001-3-3603, Technical Note TN-EMC-94-01, Dept. of Electrical and Computer Engineering, Concordia University, March 31, 1994, 57 pages.
Antenna Performance and EMC on Aircraft
Aircraft carry many antennas for communication and other purposes. Each antenna must be certified to have suitable pattern coverage over the frequency bandwidth of the associated system, to ensure the integrity of that system. Aircraft antennas interact strongly with the aircraft itself and with one another. In this project both computer modeling and scale-model measurement were used to investigate the radiation patterns of various antennas on aircraft and helicopters.
Antenna-to-antenna coupling poses a severe problem in electromagnetic compatibility on a typical aircraft. Each system radiates both the desired frequency and harmonics of that frequency. The antenna can couple into other antennas on the aircraft and cause electromagnetic interference. Each system is sensitive to the signals and harmonics of the signals radiated by other systems and can thus be a victim of electromagnetic interference. The full evaluation of source and victim pairs is thus a complex problem that must be addressed systematically to ensure the electromagnetic compatibility of the full complement of avionics systems carried by a typical search and rescue aircraft. An EMC test plan identifies critical source and victim pairs to be tested to ensure the proper operation of all systems.
This project was funded by the National Sciences and Engineering Research Council of Canada.
Publications
Stanley J. Kubina, Christopher W. Trueman, and David Gaudine, “Modeling the Characteristics of a CH-149 Helicopter Hybrid HF Antenna,” 17th Annual Review of Progress in Applied Computational Electromagnetics, March 19 to 23, 2001, Monterey, California.
D.R. Munn, C.W. Trueman, and Y.M.M. Antar, “Gaining Insight Into HF Resonance Features Using Model Morphing,” Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), pp. 195-199, Winnipeg, Manitoba, July 30-August 2, 2000.
D.R. Munn, C.W. Trueman, and Y. Antar, “Novel Method of Improving Model Confidence Through Metamorphosis,” Millennium Conference on Antennas and Propagation, AP2000, European Space Agency, Davos, Switzerland, April 9-14, 2000.
D.R. Munn and C.W. Trueman, “Improving Model
Confidence through Metamorphosis,” ACES 16th Annual Review of
Progress in Applied Computational Electromagnetics, pp. 373-380, Monterey,
California, March 20-24, 2000.
D.R. Munn and C.W. Trueman, “Model Morphing for
Insight into the HF Assessment Parameters,” ACES 16th Annual Review
of Progress in Applied Computational Electromagnetics, pp. 381-386, Monterey,
California, March 20-24, 2000.
Stanley J. Kubina, Christopher W. Trueman, and
David Gaudine, “A Virtual Radiation Pattern Range and Its Uses – C-130/Hercules
HF Notch Antenna,” ACES 16th Annual Review of Progress in Applied
Computational Electromagnetics, pp. 356-364, Monterey, California, March 20-24,
2000.
S.J. Kubina and C.W. Trueman, "Computer Simulations of an Aircraft HF Notch Antenna, IEEE Conference on Electromagnetic Computations, Tuscon, Arizona, June 1-3, 1998.
S.J. Kubina, C.W. Trueman, and D. Gaudine, "Experiments with NEC3 and NEC4 - Simulation of Helicopter Antennas, 13th Annual Review of Progress of the Applied Computational Electromagnetics Society, Monterey, California, March 17-21, 1997.
C.W. Trueman and S.J. Kubina, "Fields of Complex Surfaces Using Wire Grid Modelling," IEEE Trans. on Magnetics, Vol. 27, No. 5, pp. 4262-4267, Sept. 1991.
C.W. Trueman and S.J. Kubina, "Verifying Wire-Grid Model Integrity with Program CHECK", Applied Computational Electromagnetics Society Journal, Vol. 5, No. 2, pp. 17-42, Winter 1990.
Helix Antennas for Spacecraft Applications
A helix antenna is an efficient radiator of a circularly-polarized field in a narrow beam, over a wide bandwidth. Multi-section helices can be used to increase the bandwidth. Helices are often flown on spacecraft, where the desired performance must be achieved with an antenna of the lightest possible weight and most compact design. In research funded by the Canadian Space Agency in 1995 and 1996, computer modeling was used to study a very general class of helix antennas, with a view to optimizing the design for spacecraft applications. Measurements of the radiation patterns of various helices over a wide frequency range were used to validate the calculations for cylindrical helices, two-section cylindrical helices and tapered helices.
In the current project, software is being created to design a cylindrical helix antenna to meet a performance specification including the minimum gain, the maximum axial ratio, the beam width, and the desired bandwidth. The software package identifies combinations of helix pitch angle and length that with meet the performance specification. It may be that no helix of this design can achieve the required performance, in which case a more complex design will be required. The software package permits the engineer to systematically explore the performance of cylindrical helices to determine what is possible from this relatively simple design.
This research was funded by the National Sciences and Engineering Research Council of Canada and by the Canadian Space Agency.
Publications
M. Slater and C.W. Trueman, “Design Software for
Cylindrical Helix Antennas,” ACES 16th Annual Review of Progress in
Applied Computational Electromagnetics, pp. 281-285, Monterey, California,
March 20-24, 2000.
C.W. Trueman, S.J. Kubina and M. Slater, "Modelling Helix Antennas with NEC4", 1997 Digest, IEEE Antennas and Propagation Society International Symposium 1997, pp. 1584-1487, Montreal, July 13-18, 1997.
N. Sultan, T. Pellerin, C.W. Trueman, and S.J. Kubina, "Design and Validation of Uniform Helical Antennas, with Varying Diameters, Using NEC", "Progress in Electromagnetics Research Symposium"(PIERS), Hong Kong, January 6-9, 1997.
N. Sultan, T. Pellerin, C.W. Trueman, and S.J. Kubina, "Stepped Helical Antenna Modelling Using NEC and Validation by Measurements", Symposium on Antenna Technology and Applied Electromagnetics (ANTEM '96), August 6-9, 1996, Montreal.
C.W. Trueman, N. Sultan, S.J. Kubina, and T. Pellerin, "Software for Modelling Helix Antennas with NEC and Validation by Measurement", 12th Annual Review of Progress of the Applied Computational Electromagnetics Society, Monterey, California, March 21-26, 1996.
Validation of Various Modeling Codes in Computational Electromagnetics
Code validation is the comparison of computed data such as antenna radiation patterns, antenna near fields, or radar cross-section with measured data to verify that the computational method is correct, and to assess the accuracy of the computational method. Code validation serves to identify the limitations of a computational method, such as the frequency bandwidth over which the computer model obtains useful results. Code validation is carried out in conjunction with all the projects carried out at the EMC Laboratory.
Publications
C.W. Trueman and S.R. Mishra, "Numerical Computation and Measurement: Building an Experience Base for Code Validation", invited paper, Latsis Symposium 1995 on Computational Electromagnetics, Zurich, Switzerland, Sept. 19-21, 1995.
S.J. Kubina and C.W. Trueman, "The Validation of EM Modeling Codes - A User Viewpoint", The Applied Computational Electromagnetics Society Journal, Special Issue on Electromagnetics Computer Code Validation, 1989.
C.W. Trueman, S.R. Mishra, C.L. Larose and R.K. Mongia, "Resonant Frequencies and Q Factors of Dielectric Parallelepipeds by Measurement and by FDTD", IEEE Trans. on Instrumentation, Vol. 44, No. 2, pp. 322-325, April 1995.
Code Validation Data Base
In this collaboration between the David Florida Laboratory of the Canadian Space Agency and Concordia's EMC Laboratory, a "data base" of radar cross-section measurements and computations was built up over a period of about five years. The RCS measurements and computations are available to the community for the purpose of validating existing and new computer modeling codes in computational electromagnetics. At DFL, the radar cross-section of various simple and complex targets has been measured using state-of-the-art instrumentation and facilities. Computations are done at Concordia using modeling techniques such as wire-grid modeling, surface-patch modeling, and the finite-difference time-domain method, to demonstrate the agreement currently possible. Targets include simple and complex objects of metal, and cubes and rods of low and high-permittivity dielectric.
Publications
C.L Larose, S.R. Mishra, and C.W. Trueman, "Measured RCS Polar Contour Maps for Code Validation", Applied Computational Electromagnetics Society Journal, Vol. 11, No. 3, pp. 25-43, November, 1996.
C.W. Trueman and S.R. Mishra, "A WWW-Based Data Base for Code Validation", 12th Annual Review of Progress of the Applied Computational Electromagnetics Society, Monterey, California, March 21-26, 1996.
S.R. Mishra, C.L. Larose and C.W. Trueman, "Precision Radar Cross-Section Measurements for Computer Code Validation", IEEE Trans. on Instrumentation and Measurement, Vol. 42, No. 2, pp. 179-185, April 1993.
C.W. Trueman, S.J. Kubina, S.R. Mishra and C. Larose, "RCS of Scatterers with Attached Wires," IEEE Trans. on Antennas and Propagation, Vol. 41, No. 3, pp. 351-355, March 1993.
C.W. Trueman, S.J. Kubina, S.R. Mishra and C. Larose, "RCS of Four Fuselage-Like Scatterers at HF Frequencies", IEEE Trans. on Antennas and Propagation, Vol. AP-40, No. 2, pp. 236-240, Feb. 1992.
Broadcast Antennas and Steel-Tower Power Lines
To ensure that commercial radio stations in the AM band in a given area can be enjoyed by the public without interference from other stations in nearby cities, each broadcaster must build and maintain a directional antenna. The antenna must provide good signal strength in the station's service area, but at the same time protect other stations in nearby cities by radiating very little signal toward those cities. Unfortunately, large metallic structures near the station's antenna, such a tower carrying other antennas, or a steel-tower power line, can effectively scatter the station's signal toward cities the station must protect, and give rise to interference. This project uses computational electromagnetics to assess the degree to which structures such as another antenna tower or a steel-tower power line scatters a station's signal. Computer modeling is used to design "detuners" which are installed on the towers to suppress the scattered signal. Computer modeling can greatly reduce the cost of modifying any power line to reduce scattering sufficiently that no significant interference can be measured.
Publications
C.W. Trueman, S.J. Kubina, J. Provost, P. Labarre and G. Lussier, "Quick and Effective Adjustment of Stub Detuners by a Two-Loops Method", IEEE Trans. on Broadcasting, Vol. 40, No. 3, pp. 141-176, Sept. 1994.
C.W. Trueman and S.J. Kubina, "Scattering from Power Lines with the Skywire Insulated from the Towers", IEEE Trans. on Broadcasting, Vol. 40, No. 2, pp. 53-62, June 1994.
C.W. Trueman and S.J. Kubina, "Power Line Tower Models Above 1000 kHz in the Standard Broadcast Band", IEEE Trans. on Broadcasting, Vol. 36, No. 3, pp. 207-218, Sept. 1990.
C.W. Trueman, T.M. Roobroeck, and S.J. Kubina, "Stub Detuners for Free-Standing Towers", IEEE Trans. on Broadcasting, Vol. 35, No. 4, pp. 325-338, Dec. 1989.
C.W. Trueman, "Modelling a Standard Broadcast Directional Array with the Numerical Electromagnetics Code", IEEE Trans. on Broadcasting, vol. 34, No. 1, pp. 39-49, March, 1988.
C.W. Trueman and S.J. Kubina, "Ground Loss Effects in Power Line Reradiation at Standard Broadcast Frequencies", IEEE Trans. on Broadcasting, vol. 34, No. 1, pp. 24-38, March, 1988.
C.W. Trueman and S.J. Kubina, "Detuning Power Lines by Isolating Towers for the Suppression of Resonances", IEEE Trans. on Broadcasting, Vol. BC-32, No. 3, pp. 44-55, Sept., 1986.
C.W. Trueman and S.J. Kubina, "Initial Assessment of Reradiation from Power Lines", IEEE Trans. on Broadcasting, Vol. BC-31, No. 3, pp. 51-65, Sept., 1985.
C.W. Trueman, S.J. Kubina, R.C. Madge and D.E. Jones, "Comparison of Computed RF Current Flow on a Power Line with Full Scale Measurements," IEEE Trans. on Broadcasting, Vol. BC-30, No. 3, pp. 97-107, Sept., 1984.
C.W. Trueman, S.J. Kubina and J.S. Belrose, "Corrective Measures for Minimizing the Interaction of Power Lines with MF Broadcast Arrays," IEEE Trans. on Electromagnetic Compatibility, Vol. EMC-25, No. 3, pp. 329-339, Aug. 1983.
C.W. Trueman and S.J. Kubina, "Numerical Computation of the Reradiation from Power Lines at MF Frequencies," IEEE Trans. on Broadcasting, Vol. BC-27, No. 2, pp. 39-45, June, 1981.
C.W. Trueman and S.J. Kubina, "Analysis and Detuning of Reradiation from Power Lines at MF Frequencies using the Numerical Electromagnetics Code," Final Report, DOC/CRC Contract No. 36001-6-3574/01-ST, Technical Note TN-EMC-87-04, Dept. of Electrical Engineering, Concordia University, September 1, 1987.
C.W. Trueman and
S.J. Kubina, "Evaluations of Computer Models of Steel Tower Power
Lines," Final Report, DOC/CRC Contract No. OSU82-00157, Technical Note
TN-EMC-86-04, Dept. of Electrical Engineering,
C.W. Trueman and S.J. Kubina, "Initial Assessment of Reradiation from a Power Line and Its Detuning by Tower Isolation," Final Report, DOC/CRC Contract No. OSU82-00157, Technical Note TN-EMC-85-05, Dept. of Electrical Engineering, Concordia University, Montreal, May 31, 1985.
C.W. Trueman and S.J. Kubina, "Recent Advances in the Computer Modeling of Type V1S Towers at MF Frequencies," Final Report, DOC/CRC Contract No.OSU82-00157, Technical Note TN-EMC-83-04, Dept. of Electrical Engineering, Concordia University, Montreal, Sept. 29, 1983.
C.W. Trueman and S.J. Kubina, "Corrective Measures for Minimizing the Interaction of Power Lines with MF Broadcast Antennas," Final Report, DOC/CRC Contract No. OSU81-00192, Technical Note TN-EMC-82-02, Dept. of Electrical Engineering, Concordia University, Montreal, May 17, 1982.
C.W. Trueman and S.J. Kubina, "Prediction by Numerical Computation of the Reradiation from and the Detuning of Power Transmission Lines," Final Report, DOC/CRC Contract No. OSU80-00121, Technical Note TN-EMC-81-03, Dept. of Electrical Engineering, Concordia University, Montreal, May 13, 1981.
C.W. Trueman and
S.J. Kubina, "AM Reradiation Project," Final Report, DOC/CRC Contract
No. OSU79-0066, Technical Note TN-EMC-80-03, Dept. of Electrical Engineering,
Teaching Electromagnetics
Students in electromagnetics courses often have problems visualizing the propagation of pulses on transmission line circuits. To aid in teaching transients on transmission lines I have written a program called BOUNCE which uses computer animation to bring propagation problems to life. BOUNCE can show a pulse starting at a generator, propagating at a finite speed along a transmission line, being partially reflected from various discontinuities, and finally reaching a load. This is a very effective classroom demonstration. BOUNCE provides a "laboratory" in which students can test their pencil-and-paper solutions to homework problems. Also, BOUNCE is useful in the classroom for showing, graphically, the change from "transient" to "sinusoidal steady state" when the generator is sinusoidal. The program shows the build up of the steady state response as the superposition of many reflections of ever-smaller amplitude, and prepares the students for studying transmission lines in the sinusoidal steady state.
To aid in teaching transmission lines in the sinusoidal steady state, I wrote a program called "TRLINE" standing for "Transmission LINE". The program solves various transmission line circuits in the sinusoidal steady state and illustrates the use of the Smith Chart. Like BOUNCE, the TRLINE program can be used at home by students as a "laboratory" for verifying their homework assignments. TRLINE permits me to illustrate advanced concepts such as microwave filters in the classroom, and so prepare students for the elective "Microwave Circuits" course.
Publications
C.W. Trueman, “Interactive Transmission Line Computer Program for Undergraduate Teaching,” IEEE Trans. on Education, Vol. 43, No. 1, pp. 1-14, February 2000.
C.W. Trueman, "Teaching Transmission Line Transients Using Computer Animation", Frontiers in Education Conference, Puerto Rico, Nov. 10-13, 1999.