Antenna Design and Propagation Channel Characterization

Antennas are an indispensable component in any RF communication or sensing system. The design of antennas is a cut-and-try process that can be greatly enhanced by the use of a computational electromagnetic solver coupled with an effective optimization algorithm. In our research, we are exploring various design methodologies such as genetic algorithms, particle swarm optimization, artificial neural networks, and vector fitting to achieve antenna designs with optimal performance. The topics of our investigation include: (i) electrically small antennas, (ii) ultra-wideband antennas, (iii) reconfigurable supergain arrays, and (iv) antenna circuit modeling. Results from our research have found applications in non-line-of-sight communication at HF/VHF frequencies, commercial UWB communications, low-frequency radio telescope systems, and wireless power transfer. We are also studying the radiowave propagation channels in complex environments such as forested terrains and urban areas. By exploiting the knowledge gained from the propagation channel studies, we hope to design antennas that maximize power transfer in these environments for enhanced communication and sensing.




Publications and Presentations:

2003

H. Choo and H. Ling, "Design of broadband and dual-band microstrip antennas on high-dielectric substrate using the genetic algorithm," IEE Proc. - Microwaves Antennas Propagat., vol. 150, pp. 137-142, June 2003.

H. Choo and H. Ling, "Design of electrically small planar antennas using an inductively coupled feed," Elect. Lett., vol. 39, pp. 1563-1564, October 2003.

H. Choo and H. Ling, "Design of planar, electrically small antennas with inductively coupled feed using a genetic algorithm," International IEEE AP-S Symposium, vol. 1, pp. 300-303, Columbus, OH, June 2003.

A. Kerkhoff and H. Ling, "Design of a planar monopole antenna for use in ultra-wideband having a band-notched characteristic," International IEEE AP-S Symposium, vol. 1, pp. 830-833, Columbus, OH, June 2003.

H. Choo and H. Ling, "Design of electrically small wire antennas using a Pareto genetic algorithm," URSI National Radio Science Meeting, Columbus, OH, June 2003. (1st Place, Student Paper Competition).

2004

A. Kerkhoff, R. L. Rogers and H. Ling, "Design and analysis of planar monopole antennas using a genetic algorithm approach," IEEE Trans. Antennas Propagat., vol. AP-52, pp. 2709-2718, October 2004.

S. Lim, H. Choo, R. L. Rogers and H. Ling, "An electrically small antenna for maximizing transmission into HF ground waves" Elect. Lett., vol. 22, pp. 1388-1389, October 2004.

Y. Kim, Y. Noh and H. Ling, "Design of an ultra-broadband on-glass antenna with a 250-ohm system impedance for automobiles," Elect. Lett., vol. 40, pp. 1566-1568, December 2004.

S. Lim, H. Choo, R. L. Rogers and H. Ling, "A top-loaded, inductively-coupled small antenna for HF ground wave transmission," International IEEE AP-S Symposium, vol. 3, pp. 3187-3190, Monterey, CA, June 2004.

H. Choo, C. Cho and H. Ling, "Design of tag antennas for RFID using a Pareto genetic algorithm," URSI National Radio Science Meeting, p. 265, Monterey, CA, June 2004.

A. Kerkhoff and H. Ling, "A parametric study of band-notched UWB planar monopoles," International IEEE AP-S Symposium, vol. 2, pp. 1768-1771, Monterey, CA, June 2004.

2005

H. Choo, R. L. Rogers and H. Ling, "Design of electrically small wire antennas using a Pareto genetic algorithm," IEEE Trans. Antennas Propagat., vol. AP-53, pp. 1038-1046, March 2005.

T. Su and H. Ling, "Array beamforming in the presence of a mounting tower using genetic algorithms," IEEE Trans. Antennas Propagat., vol. AP-53, pp. 2011-2019, June 2005.

H. Choo, R. L. Rogers and H. Ling, "On the Wheeler cap measurement of the efficiency of microstrip antennas," IEEE Trans. Antennas Propagat., vol. AP-53, pp. 2328-2332, July 2005.

S. Lim, R. L. Rogers and H. Ling, "Design of electrically small ground planes for HF ground wave transmission," Elect. Lett., vol. 41, pp. 993-994, September 2005.

Y. Noh, Y. Kim and H. Ling, "A broadband on-glass antenna with a mesh-grid structure for automobiles," Elect. Lett., vol. 41, pp. 1148-1149, October 2005.

S. Lim, R. L. Rogers and H. Ling, "Ground plane size reduction in monopole antennas for ground wave transmission," International IEEE AP-S Symposium, paper no. SP15p01a, 4 pp., Washington, DC, July 2005.

S. Lim, R. L. Rogers and H. Ling, "Frequency tuning of an electrically small antenna for HF ground wave transmission," International IEEE AP-S Symposium, paper no. S021p09a, 4 pp., Washington, DC, July 2005.

Y. Kim, M. Gerwell and H. Ling, "Application of the Cauchy method to genetic algorithms for broadband antenna design," International IEEE AP-S Symposium, paper no. SP62p03a, 4 pp., Washington, DC, July 2005.

Y. Kim and H. Ling, "Equivalent circuit modeling of UWB antennas using a modified Cauchy method," URSI National Radio Science Meeting, paper no. S046p07u, 1 p., Washington, DC, July 2005.

2006

S. Lim, R. L. Rogers and H. Ling, "A tunable electrically small antenna for ground wave transmission," IEEE Trans. Antennas Propagat., vol. AP-54, pp. 417-421, February 2006.

Y. Kim and H. Ling, "Equivalent circuit modeling of broadband antennas using a rational function approximation," Microwave Optical Tech. Lett., vol. 48, pp. 950-953, May 2006.

S. Lim and H. Ling, "Design of a closely spaced, folded Yagi antenna," IEEE Antennas Wireless Propagat. Lett., vol. 5, pp. 302-305, May 2006.

S. Lim and H. Ling, "Design of a thin, efficient, electrically small antenna using multiple foldings," Elect. Lett., vol. 42, pp. 895-896, July 2006.

H. Choo and H. Ling, "Electrically small planar antennas with inductively coupled feed," US Patent No. 7061440, issued June 13, 2006.

Y. Kim and H. Ling, "Equivalent circuit modeling of broadband antennas using vector fitting and particle swarm optimization," International IEEE AP-S Symposium, pp. 3555-3558, Albuquerque, NM, July 2006.

Y. Kim, S. Keely, J. Ghosh and H. Ling, "Broadband antenna optimization using an artificial neural network," URSI National Radio Science Meeting, p. 425, Albuquerque, NM, July 2006.

S. Lim and H. Ling, "Design and evaluation of a closely spaced Yagi antenna over ground," International IEEE AP-S Symposium, pp. 2021-2024, Albuquerque, NM, July 2006.

S. Lim and H. Ling, "Design of an electrically small planar antenna using multiple foldings," URSI National Radio Science Meeting, p. 411, Albuquerque, NM, July 2006.

S. Lim, R. L. Rogers and H. Ling, "Optimization of the folded conical helix antenna using a genetic algorithm," URSI National Radio Science Meeting, p. 427, Albuquerque, NM, July 2006.

2007

A. Kerkhoff and H. Ling, "Design of a band-notched planar monopole antenna using genetic algorithm optimization," IEEE Trans. Antennas Propagat., vol. AP-55, pp. 604-610, March 2007.

Y. Kim, S. Keely, J. Ghosh and H. Ling, "Application of artificial neural networks to broadband antenna design based on a parametric frequency model," IEEE Trans. Antennas Propagat., vol. AP-55, pp. 669-674, March 2007.

S. Lim and H. Ling, "Design of an electrically small Yagi antenna," Elect. Lett., vol. 43, pp. 3-4, March 2007.

S. Lim and H. Ling, "Printable Yagi antenna with closely spaced elements," Microwave Optical Tech. Lett., vol. 49, pp. 2106-2109, September 2007.

Y. Kim and H. Ling, "Realisable rational function approximations for the equivalent circuit modeling of broadband antennas," IET Proc. - Microwaves Antennas Propagat., vol. 1, pp. 1046-1054, October 2007.

Y. Kim and H. Ling, "Investigation of coupled mode behaviour of electrically small meander antennas," Elect. Lett., vol. 43, pp., November 2007.

S. Lim and H. Ling, "Design of an electrically small, pattern reconfigurable Yagi antenna," Elect. Lett., vol. 43, pp., November 2007.

S. Lim and H. Ling, "A two-element, electrically small Yagi antenna," International IEEE AP-S Symposium, Honolulu, HI, June 2007.

S. Lim and H. Ling, "Design of a planar, closely spaced Yagi antenna," International IEEE AP-S Symposium, Honolulu, HI, June 2007.

A. Kerkhoff and H. Ling, "Application of Pareto genetic algorithm to the design of broadband dipole elements for use in the Long Wavelength Array (LWA)," International IEEE AP-S Symposium, Honolulu, HI, June 2007.

S. Lim and H. Ling, "A pattern reconfigurable, electrically small Yagi antenna," 2007 North American Radio Science Meeting, Ottawa, Canada, July 2007.

S. Moon, S. Lim, H. Ham, J. Woo and H. Ling, "A printable, reduced-height monopole Yagi antenna using spiral top loading," 2007 North American Radio Science Meeting, Ottawa, Canada, July 2007.

H. Ling, "Electrically small antennas - theory, design, and challenges," UCLA Workshop on Emerging Antenna Research for Wireless Communications, Los Angeles, CA, February 20, 2007.

2008

Y. Li, N. J. Whitelonis and H. Ling, "Simulation and measurement of the effective propagation constant of a cut-wire array," Elect. Lett., vol. 44, pp. 893-894, July 2008.

Y. Kim and H. Ling, "On the coupled mode behavior of electrically small antennas," URSI National Radio Science Meeting, San Diego, CA, July 2008.

A. Kerkhoff and H. Ling, "Use of a receive-based definition of coupling between two antennas to reduce mutual coupling effects in a low frequency radio telescope array," International IEEE AP-S Symposium, San Diego, CA, July 2008.

A. Kerkhoff and H. Ling, "Pareto genetic algorithm optimization of broadband dipole antenna elements for use in a low frequency radio telescope array including mutual coupling effects," International IEEE AP-S Symposium, San Diego, CA, July 2008.

Y. Li, H. Ling, M. Mayes and J. Mayes, "Current decomposition in helical antennas using ESPRIT," International IEEE AP-S Symposium, San Diego, CA, July 2008.

Y. Li and H. Ling, "On extracting the effective propagation constant of a cut-wire array," URSI International Union of Radio Science General Assembly, Chicago, IL, August 2008.

2009

Y. Li and H. Ling, "Numerical modeling and mechanism analysis of VHF wave propagation in forested environments using the equivalent slab model," Progress in Electromag. Research, vol. 91, pp. 17-34, 2009.

Y. Li and H. Ling, "Extraction of wave propagation mechanisms in a cut-wire array using the ESPRIT algorithm," IEEE Antennas Wireless Propagat. Lett., vol. 8, pp. 744-747, May 2009.

S. Lim and H. Ling, "Comparing electrically small folded conical and spherical helix antennas based on a genetic algorithm optimization," J. Electromag. Waves Applications, vol. 23, no. 11/12, page 1585-1593, 2009.

Y. Li, M. Wu, A. E. Yilmaz and H. Ling, "Investigation of short-range radiowave propagation at HF/VHF frequencies in a forested environment," IEEE Antennas Wireless Propagat. Lett., vol. 8, pp. 1182-1185, Oct. 2009.

A. Kerkhoff and H. Ling, "Design of broadband antenna elements for a low frequency radio telescope using Pareto genetic algorithm optimization," Radio Science, vol. 44, 11 pp., December 2009.

Y. Li and H. Ling, "Extraction of the effective propagation and attenuation constants in a cut-wire array," 2009 IEEE International Workshop on Antenna Technology - Small Antennas and Novel Metamaterials, Santa Monica, CA, March 2009.

Y. Li and H. Ling, "Wave propagation in a randomized cut-wire array," 2009 International IEEE AP-S Symposium, Charleston, SC, June 2009.

Y. Li and H. Ling, "Extraction of wave propagation mechanisms in a cut-wire array," 2009 URSI National Radio Science Meeting, Charleston, SC, June 2009.

2010

Y. Li, A. Alu and H. Ling, "Simulation and measurement of surface wave propagation along a metal cut-wire array," IEEE Antennas Wireless Propagat. Lett., vol. 9, pp. 179-182, 2010.

Y. Li and H. Ling, "Improved current decomposition in helical antennas using the ESPRIT algorithm," Progress in Electromag. Research, vol. 106, pp. 279-293, 2010.

I. J. Yoon and H. Ling, "Realizing efficient wireless power transfer using small folded cylindrical helix dipoles," IEEE Antennas Wireless Propagat. Lett., vol. 9, pp. 846-849, August 2010.

Y. Li and H. Ling, "Investigation of wave propagation in a dielectric rod array: toward the understanding of HF/VHF propagation in a forest," IEEE Trans. Antennas Propagat., vol. AP-58, pp. 4025-4032, December 2010.

Y. Li and H. Ling, "Investigation of wave propagation in a dielectric rod array," 2010 URSI National Science Meeting, Boulder, CO, January 2010. (3rd place, student paper contest)

Y. Li and H. Ling, "Wave propagation in a random dielectric rod array," 2010 International IEEE AP-S Symposium, Toronto, Canada, July 2010.

Y. Li and H. Ling, "Investigation of directive antennas in a metal cut-wire array," 2010 International IEEE AP-S Symposium, Toronto, Canada, July 2010.

I.-J. Yoon, S. Nam and H. Ling, "Near-field coupling between small folded cylindrical helix dipoles," 2010 International IEEE AP-S Symposium, Toronto, Canada, July 2010.

H. Ling, "Modeling and understanding of radiowave propagation in forested environments," National Science Foundation ENG Program Grantee's Conference, Honolulu, HI, December 1, 2010.

2011

S. M. Moon, H. K. Ryu, J. M. Woo and H. Ling, "Miniturization of a λ/4 microstrip antenna using perturbation effect and plate loading for low-VHF-band applications," Elect. Lett., vol. 47, pp. 162-164, February 2011.

I. J. Yoon and H. Ling, "An electrically small Yagi antenna with enhanced bandwidth characteristics using folded cylindrical helix dipoles," Microwave Optical Tech. Lett., vol. 53, pp. 1231-1233, June 2011.

A. Kerkhoff and H. Ling, "A simplified method for reducing mutual coupling effects in low frequency radio telescope phased arrays," IEEE Trans. Antennas Propagat., vol. 59, pp. 1838-1845, June 2011.

I. J. Yoon and H. Ling, "Investigation of near-field wireless power transfer under multiple transmitters," IEEE Antennas Wireless Propagat. Lett., vol. 10, pp. 662-665, 2011.

Y. Li and H. Ling, "Investigation of directive antenna radiation in a metal cut-wire array," 2011 URSI National Science Meeting, Boulder, CO, January 2011.

Y. Li, M. Wu, A. E. Yilmaz and H. Ling, "Analysis of wave propagation mechanisms in large-scale dielectric rod arrays," 2011 URSI National Radio Science Meeting, Spokane, WA, July 2011.

I.-J. Yoon B. W. Jun and H. Ling, "Near-field wireless power transfer under multiple transmitter and multiple receiver scenarios," 2011 URSI National Radio Science Meeting, Spokane, WA, July 2011.

I.-J. Yoon and H. Ling, "Enhancement of near-field wireless power transfer using small directive antennas," 2011 URSI National Radio Science Meeting, Spokane, WA, July 2011.

I.-J. Yoon and H. Ling, "Realizing efficient wireless power transfer in the near-field region using electrically small antennas," in Wireless Energy Transfer based on Electromagnetic Resonance: Principles and Engineering Explorations, 22 pages, InTech, Editor K. Y. Kim, 2011.

2012

Y. Li, A. Alu and H. Ling, "Investigation of leaky wave propagation and radiation in a metal cut-wire array," IEEE Trans. Antennas Propagat., vol. 60, pp. 1630-1634, March 2012.

Y. Li and H. Ling, "Surface wave propagation along a one-dimensional metal cut-wire array," 2012 URSI National Science Meeting, Boulder, CO, January 2012.

I.-J. Yoon and H. Ling, "Investigation of material effects on near-field wireless power transfer," 2012 International IEEE AP-S Symposium, Chicago, IL, July 2012. (Honorable mention, student paper contest)

2013

I. J. Yoon and H. Ling, "Investigation of near-field wireless power transfer in the presence of lossy dielectric materials," IEEE Trans. Antennas Propagat., vol. 61, pp. 482-488, January 2013.

Y. Li, M. Wu, A. E. Yilmaz and H. Ling, "On wave propagation mechanisms in a dielectric rod array," IEEE Trans. Antennas Propagat., vol. AP-61, pp. 2337-2342, April 2013.

G. Byun, H. Choo and H. Ling, "Optimum placement of DF antenna elements for accurate DOA estimation in a harsh platform environment," IEEE Trans. Antennas Propagat., vol. AP-61, pp. 4783-4791, September 2013.

I. J. Yoon and H. Ling, "Design of an electrically small circularly polarized turnstile antenna and its application to near-field wireless power transfer," accepted for publication in IEE Proc. - Microwaves Antennas Propagat., September 2013.

I.-J. Yoon and H. Ling, "Design of an electrically small CP antenna with application to alleviating orientation dependence in near-field wireless power transfer," 2013 European Conference on Antennas and Propagation, pp. 2383-2384, Gothenburg, Sweden, April 2013.

C. Li and H. Ling, "A planarized, capacitor-loaded loop structure for wireless power transfer," 2013 International IEEE AP-S Symposium, Orlando, FL, July 2013.