Books
Selected Publications
LargeScale Simulations

Ö. Ergül and L. Gürel, “Fast and accurate analysis of largescale composite structures with the parallel multilevel fast multipole algorithm,” J. Opt. Soc. Am. A., vol. 30, no. 3, pp. 509–517, Mar. 2013. View More

Ö. Ergül and L. Gürel, “Accurate solutions of extremely large integralequation problems in computational electromagnetics,” IEEE Proceedings, vol. 101, no. 2, pp. 342–349, Feb. 2013. View More

Ö. Ergül, “Analysis of composite nanoparticles with surface integral equations and the multilevel fast multipole algorithm,” J. Opt., vol. 14, no. 6, pp. 0627011–0627014, Jun. 2012. View More

Ö. Ergül, “Fast and accurate solutions of electromagnetics problems involving lossy dielectric objects with the multilevel fast multipole algorithm,” Eng. Anal. Bound. Elem., vol. 36, no. 3, pp. 423–432, Mar. 2012. View More
LargeScale Simulations

Ö. Ergül, “Parallel implementation of MLFMA for homogeneous objects with various material properties,” Prog. Electromagn. Res., vol. 121, pp. 505–520, 2011. View More

Ö. Ergül, “Solutions of largescale electromagnetics problems involving dielectric objects with the parallel multilevel fast multipole algorithm,” J. Opt. Soc. Am. A., vol. 28, no. 11, pp. 2261–2268, Nov. 2011. View More

Ö. Ergül and L. Gürel, “Rigorous solutions of electromagnetic problems involving hundreds of millions of unknowns,” IEEE Antennas Propag. Mag., vol. 53, no. 1, pp. 18–27, Feb. 2011. View More

L. Gürel and Ö. Ergül, “Fast and accurate solutions of extremely large integralequation problems discretised with tens of millions of unknowns,” Electron. Lett., vol. 43, no. 9, pp. 499–500, Apr. 2007. View More
Parallelization of MLFMA

L. Gürel and Ö. Ergül, “Hierarchical parallelization of the multilevel fast multipole algorithm (MLFMA),” IEEE Proceedings, vol. 101, no. 2, pp. 332–341, Feb. 2013. View More

Ö. Ergül and L. Gürel, “A hierarchical partitioning strategy for an efficient parallelization of the multilevel fast multipole algorithm,” IEEE Trans. Antennas Propag., vol. 57, no. 6, pp. 1740–1750, Jun. 2009. View More

Ö. Ergül and L. Gürel, “Efficient parallelization of the multilevel fast multipole algorithm for the solution of largescale scattering problems,” IEEE Trans. Antennas Propag., vol. 56, no. 8, pp. 2335–2345, Aug. 2008. View More

Ö. Ergül and L. Gürel, “Hierarchical parallelisation strategy for multilevel fast multipole algorithm in computational electromagnetics,” Electron. Lett., vol. 44, no. 1, pp. 3–5, Jan. 2008. View More
EM Optimization

Ş. Yazar and Ö. Ergül, “Design and optimization of nanooptical couplers based on photonic crystals involving dielectric rods of varying lengths,” Turk. J. Elec. Eng. & Comp. Sci., vol. 30, no. 6, pp. 2339–2354, Dec. 2022. View More

B. Karaosmanoğlu, H. Eray, and Ö. Ergül, “Fullwave optimization of threedimensional photoniccrystal structures involving dielectric rods,” J. Opt. Soc. Am. A., vol. 37, no. 7, pp. 1103–1113, Jul. 2018. View More

G. Karaova, A. Altınoklu, and Ö. Ergül, “Fullwave electromagnetic optimisation of corrugated metallic reflectors using a multigrid approach,” Sci. Rep., vol. 8, no. 1267, Jan. 2018. View More

A. Altınoklu, B. Karaosmanoğlu, and Ö. Ergül, “Electromagnetic optimization of corrugated metallic sheets for maximum power focusing,” J. Electromagn. Waves Appl., vol. 31, no. 8, pp. 837–849, Apr. 2017. View More

C. Önol, S. Alkıs, Ö. Gökçe, and Ö. Ergül, “Multifrequency and multidirection optimizations of antenna arrays using heuristic algorithms and the multilevel fast multipole algorithm,” Radio Sci., vol. 51, no. 7, pp 1094–1108, Jul. 2016. View More
EM Optimization

C. Önol, B. Karaosmanoğlu, and Ö. Ergül, “Efficient and accurate electromagnetic optimizations based on approximate forms of MLFMA,” IEEE Antennas Wireless Propag. Lett., vol. 15, pp. 1113–1115, Apr. 2016. View More

C. Önol and Ö. Ergül, “Optimizations of patch antenna arrays using genetic algorithms supported by the multilevel fast multipole algorithm,” Radioengineering, vol. 23, no. 4, pp. 1005–1014, Dec. 2014. View More

L. Gürel and Ö. Ergül, “Design and simulation of circular arrays of trapezoidaltooth logperiodic antennas via genetic optimization,” Prog. Electromagn. Res., vol. 85, pp. 243–260, 2008. View More

Ö. Ergül and L. Gürel, “Modeling and synthesis of circularsectoral arrays of logperiodic antennas using multilevel fast multipole algorithm and genetic algorithms,” Radio Sci., vol. 42, RS3018, Jun. 2007. View More
Nanostructures

G. Işıklar, Ş. Yazar, H. İbili, G. Onay, Z. El Ahdab, and Ö. Ergül, “Computational design of nanoantennas with improved power enhancement capabilities via shape optimization,” Optical Eng., vol. 62, no. 015107, Jan. 2023. View More

A. Altınoklu and Ö. Ergül, “Design, optimization, and analyses of nanooptical couplers consisting of nanocubes to construct efficient nanowire transmission systems,” Prog. Electromagn. Res. C, vol. 113, pp. 13–27, May 2021. View More

B. Karaosmanoğlu, E. Tuygar, U. Topçuoglu, and Ö. Ergül, “Improving the absorption of solar cells using antennainspired cavities,” Microw. Opt. Technol. Lett., vol. 61, no. 8, pp. 1924–1930, Aug. 2019. View More

A. Altınoklu and Ö. Ergül, “Design and optimization of twodimensional nanoarrays for directive radiation,” ACES J., vol. 34, no. 2, pp. 347–351, Feb. 2019. View More

A. Altınoklu and Ö. Ergül, “Nanooptical couplers for efficient power transmission along sharply bended nanowires,” ACES J., vol. 34, no. 2, pp. 228–233, Feb. 2019. View More

G. Isıklar, I. C. Çetin, M. Algun, and Ö. Ergül, “Design and analysis of nanoantenna arrays for imaging and sensing applications at optical frequencies,” Advanced Electromagnetics, vol. 8, no. 2, pp. 18–27, Feb. 2019. View More
Nanostructures

Ş. Yazar, et al., “Efficient and accurate electromagnetic analysis of threedimensional nanooptical structures,” Materials Sci. Forum, vol. 915, pp. 202–206, Mar. 2018. View More

H. A. Şatana, B. Karaosmanoğlu, and Ö. Ergül, “A comparative study of nanowire arrays for maximum power transmission,” in Nanowires, K. Maaz, Ed. InTech, 2017, pp. 233–253. View More

Y. E. Tunçyürek, B. Karaosmanoğlu, and Ö. Ergül, “Computational design of optical couplers for bended nanowire transmission lines,” ACES J., vol. 32, no. 7, pp. 562–568, Jul. 2017. View More

A. Yılmaz, B. Karaosmanoğlu, and Ö. Ergül, “Computational electromagnetic analysis of deformed nanowires using the multilevel fast multipole algorithm,” Sci. Rep., vol. 5, no. 8469, Feb. 2015. View More
Metamaterials

Ö. Eriş and Ö. Ergül, “Design, simulation, and measurement of nearzeroindex shells for electromagnetic beam generation,” J. Electromagn. Waves Appl., vol. 38, no. 2, pp. 213–233, 2024. View More

Ö. Ergül, “Fast and accurate analysis of homogenized metamaterials with the surface integral equations and MLFMA,” IEEE Antennas Wireless Propag. Lett., vol. 10, pp. 1286–1289, 2011. View More

Ö. Ergül, T. Malas, and L. Gürel, “Analysis of dielectric photoniccrystal problems with MLFMA and Schurcomplement preconditioners,” J. Lightwave Technol., vol. 29, no. 6, pp. 888–897, Mar. 2011. View More

Ö. Ergül and L. Gürel, “Efficient solutions of metamaterial problems using a lowfrequency multilevel fast multipole algorithm,” Prog. Electromagn. Res., vol. 108, pp. 81–99, 2010. View More

L. Gürel, Ö. Ergül, A. Ünal, and T. Malas, “Fast and accurate analysis of large metamaterial structures using the multilevel fast multipole algorithm,” Prog. Electromagn. Res., vol. 95, pp. 179–198, 2009. View More
Plasmonic Formulations

B. Karaosmanoğlu and Ö. Ergül, “Modified combined tangential formulation for stable and accurate analysis of plasmonic structures,” ACES J., vol. 34, no. 5, pp. 811–814, May 2019. View More

A. Çekinmez, B. Karaosmanoğlu, and Ö. Ergül, “Integralequation formulations of plasmonic problems in the visible spectrum and beyond,” in Dyn. Sys.  Analytical and Computational Techniques, M. Reyhanoglu, Ed. InTech, 2017, pp. 191–214. View More

B. Karaosmanoğlu, A. Yılmaz, and Ö. Ergül, “A comparative study of surface integral equations for accurate and efficient analysis of plasmonic structures,” IEEE Trans. Antennas Propag., vol. 65, no. 6, pp. 3049–3057, Jun. 2017. View More

B. Karaosmanoğlu, A. Yılmaz, U. M. Gür, and Ö. Ergül, “Solutions of plasmonic structures using the multilevel fast multipole algorithm,” Int. J. RF Microwave Comput.Aided. Eng., vol. 26, no. 4, pp. 335–341, May 2016. View More
Inkjet Structures

Ö. Eris, H. Ibili, and Ö. Ergül, “Lowcost inkjetprinted multiband frequencyselective structures consisting of Ushaped resonators,” Prog. Electromagn. Res. C, vol. 98, pp. 31–44, Jan. 2020. View More

H. Ibili, B. Karaosmanoğlu, and Ö. Ergül, “Demonstration of negative refractive index with lowcost inkjetprinted microwave metamaterials,” Microw. Opt. Technol. Lett., vol. 60, no. 1, pp. 187–191, Jan. 2018. View More

F. Mutlu, C. Önol, B. Karaosmanoğlu, and Ö. Ergül, “Inkjetprinted cagedipole antennas for radiofrequency applications,” IET Microwaves, Antennas & Propagation, vol. 11, no. 14, pp. 2016–2020, Nov. 2017. View More

S. Güler, B. Karaosmanoğlu, and Ö. Ergül, “Design, simulation, and fabrication of a novel type of inkjetprinted pixel antennas,” PIER Lett., vol. 64, pp. 51–55, Nov. 2016. View More
MLFMA

Ö. Ergül, B. Khalichi, and V. B. Ertürk, “Kernelbased fast factorization techniques,” in Integral Equations for RealLife Multiscale Electromagnetic Problems, F. Vipiana and Z. Peng, Eds. IET, 2023, pp. 75–123.

M. Kalfa, V. B. Ertürk, and Ö. Ergül, “Error analysis of MLFMA with closedform expressions,” IEEE Trans. Antennas Propag., vol 69, no. 10, pp. 6618–6623, Oct. 2021. View More

B. Karaosmanoglu and Ö. Ergül, “Acceleration of MLFMA simulations using trimmed tree structures,” IEEE Trans. Antennas Propag., vol. 69, no. 1, pp. 356–365, Jan. 2021. View More

M. Kalfa, Ö. Ergül, and V. B. Ertürk, “Error control of multipleprecision MLFMA,” IEEE Trans. Antennas Propag., vol. 66, no. 10, pp. 5651–5656, Oct. 2018. View More

Ö. Ergül, I. van den Bosch, and L. Gürel, “Twostep Lagrange interpolation method for the multilevel fast multipole algorithm,” IEEE Antennas Wireless Propag. Lett., vol. 8, pp. 69–71, 2009. View More

Ö. Ergül and L. Gürel, “Optimal interpolation of translation operator in multilevel fast multipole algorithm,” IEEE Trans. Antennas Propag., vol. 54, no. 12, pp. 3822–3826, Dec. 2006. View More

Ö. Ergül and L. Gürel, “Enhancing the accuracy of the interpolations and anterpolations in MLFMA,” IEEE Antennas Wireless Propag. Lett., vol. 5, pp. 467–470, 2006. View More
LowFrequency Simulations

A. Farshkaran and Ö. Ergül, “Implementation of the equivalence principle algorithm for potential integral equations,” IEEE Trans. Antennas Propag., vol. 67, no. 5, pp. 3249–3255, May 2019. View More

U. M. Gür and Ö. Ergül, “Accuracy of sources and nearzone fields when using potential integral equations at low frequencies,” IEEE Antennas Wireless Propag. Lett., vol. 16, pp. 2783–2786, 2017. View More

Ö. Ergül and B. Karaosmanoğlu, “Approximate stable diagonalization of the Green’s function for low frequencies,” IEEE Antennas Wireless Propag. Lett., vol. 13, pp. 1054–1056, 2014. View More

Ö. Ergül and B. Karaosmanoğlu, “Lowfrequency fast multipole method based on multipleprecision arithmetic,” IEEE Antennas Wireless Propag. Lett., vol. 13, pp. 975–978, 2014. View More
Broadband Simulations

M. Kalfa, Ö. Ergül, and V. B. Ertürk, “Multipleprecision arithmetic implementation of the multilevel fast multipole algorithm,” IEEE Trans. Antennas Propag., vol. 72, no. 1, pp. 11–21, Jan. 2024. View More

Ö. Eriş, G. Karaova, and Ö. Ergül, “A novel combined potentialfield formulation for densely discretized perfectly conducting objects,” IEEE Trans. Antennas Propag., vol. 70, no. 6, pp. 4645–4654, Jun. 2022. View More

B. Khalichi, Ö. Ergül, M. Takrimi, and V. B. Ertürk, “Broadband analysis of multiscale electromagnetic problems: Novel incompleteleaf MLFMA for potential integral equations,” IEEE Trans. Antennas Propag., vol. 69, no. 12, pp. 9032–9037, Dec. 2021. View More

B. Khalichi, Ö. Ergül, and V. B. Ertürk, “Broadband solutions of potential integral equations with NSPWMLFMA,” IEEE Trans. Antennas Propag., vol. 67, no. 6, pp. 4307–4312, Jun. 2019. View More

M. Takrimi, Ö. Ergül, and V. B. Ertürk, “Incompleteleaf multilevel fast multipole algorithm for multiscale penetrable objects formulated with volume integral equations,” IEEE Trans. Antennas Propag., vol. 65, no. 9, pp. 4914–4918, Sep. 2017. View More

M. Takrimi, Ö. Ergül, and V. B. Ertürk, “A novel broadband multilevel fast multipole algorithm with incompleteleaf tree structures for multiscale electromagnetic problems,” IEEE Trans. Antennas Propag., vol. 64, no. 6, pp. 2445–2456, Jun. 2016. View More

Ö. Ergül and B. Karaosmanoğlu, “Broadband multilevel fast multipole algorithm based on an approximate diagonalization of the Green’s function,” IEEE Trans. Antennas Propag., vol. 63, no. 7, pp. 3035–3041, Jul. 2015. View More
Surface Integral Equations

H. İbili, Y. Koyaz, U. Özmü, B. Karaosmanoğlu, and Ö. Ergül, “A novel surfaceintegralequation formulation for efficient and accurate electromagnetic analyses of nearzeroindex structures,” J. Opt., vol. 24, no. 035601, Jan. 2022. View More

B. Karaosmanoğlu and Ö. Ergül, “Generalized hybrid surface integral equations for finite periodic perfectly conducting objects,” IEEE Antennas Wireless Propag. Lett., vol. 16, pp. 1068–1071, 2017. View More

B. Karaosmanoğlu and Ö. Ergül, “EFIEtuned testing functions for MFIE and CFIE,” IEEE Antennas Wireless Propag. Lett., vol. 16, pp. 968–970, 2017. View More

B. Karaosmanoğlu, A. Altınoklu, and Ö. Ergül, “Numerical constructions of testing functions for improving the accuracy of MFIE and CFIE in multifrequency applications,” Prog. Electromagn. Res. M, vol. 51, pp. 63–70, Oct. 2016. View More

A. E. Ofluoglu, T. Çiftçi, and Ö. Ergül, “Magneticfield integral equation,” IEEE Antennas Propag. Mag., vol. 57, no. 4, pp. 134–142, Aug. 2015. View More
Surface Integral Equations

Ö. Ergül and L. Gürel, “Discretization error due to the identity operator in surface integral equations,” Comput. Phys. Comm., vol. 180, no. 10, pp. 1746–1752, Oct. 2009. View More

L. Gürel and Ö. Ergül, “Contamination of the accuracy of the combinedfield integral equation with the discretization error of the magneticfield integral equation,” IEEE Trans. Antennas Propag., vol. 57, no. 9, pp. 2650–2657, Sep. 2009. View More

Ö. Ergül and L. Gürel, “Iterative solutions of hybrid integral equations for coexisting open and closed surfaces,” IEEE Trans. Antennas Propag., vol. 57, no. 6, pp. 1751–1758, Jun. 2009. View More

Ö. Ergül and L. Gürel, “Novel electromagnetic surface integral equations for highly accurate computations of dielectric bodies with arbitrarily low contrasts,” J. Comput. Phys., vol. 227, no. 23, pp. 9898–9912, Dec. 2008. View More
Surface Integral Equations

Ö. Ergül and L. Gürel, “Stabilization of integralequation formulations for the accurate solution of scattering problems involving lowcontrast dielectric objects,” IEEE Trans. Antennas Propag., vol. 56, no. 3, pp. 799–805, Mar. 2008. View More

Ö. Ergül and L. Gürel, “Linearlinear basis functions for MLFMA solutions of magneticfield and combinedfield integral equations,” IEEE Trans. Antennas Propag., vol. 55, no. 4, pp. 1103–1110, Apr. 2007. View More

L. Gürel and Ö. Ergül, “Extending the applicability of the combinedfield integral equation to geometries containing open surfaces,” IEEE Antennas Wireless Propag. Lett., vol. 5, pp. 515–516, 2006. View More

Ö. Ergül and L. Gürel, “Improving the accuracy of the magnetic field integral equation with the linearlinear basis functions,” Radio Sci., vol. 41, RS4004, Jul. 2006. View More
Surface Integral Equations

Ö. Ergül and L. Gürel, “The use of curlconforming basis functions for the magneticfield integral equation,” IEEE Trans. Antennas Propag., vol. 54, no. 7, pp. 1917–1926, Jul. 2006. View More

Ö. Ergül and L. Gürel, “Improved testing of the magneticfield integral equation,” IEEE Microw. Wireless Comp. Lett., vol. 15, no. 10, pp. 615–617, Oct. 2005. View More

Ö. Ergül and L. Gürel, “Solidangle factor in the magneticfield integral equation,” Microw. Opt. Technol. Lett., vol. 45, no. 5, pp. 452–456, Jun. 2005. View More

L. Gürel and Ö. Ergül, “Singularity of the magneticfield integral equation and its extraction,” IEEE Antennas Wireless Propag. Lett., vol. 4, pp. 229–232, 2005. View More
Iterative Solutions

C. Önol, A. Üçüncü, and Ö. Ergül, “Efficient multilayer iterative solutions of electromagnetic problems using approximate forms of the multilevel fast multipole algorithm,” IEEE Antennas Wireless Propag. Lett., vol. 16, pp. 3253–3256, 2017. View More

Ö. Ergül and L. Gürel, “Improving iterative solutions of the electricfield integral equation via transformations into normal equations,” J. Electromagn. Waves Appl., vol. 24, no. 16, pp. 2129–2138, 2010. View More

Ö. Ergül, T. Malas, and L. Gürel, “Solutions of largescale electromagnetics problems using an iterative innerouter scheme with ordinary and approximate multilevel fast multipole algorithms,” Prog. Electromagn. Res., vol. 106, pp. 203–223, 2010. View More

Ö. Ergül and L. Gürel, “Efficient solution of the electricfield integral equation using the iterative LSQR algorithm,” IEEE Antennas Wireless Propag. Lett., vol. 7, pp. 36–39, 2008. View More
Fast Simulations

B. Karaosmanoğlu and Ö. Ergül, “Visual result prediction in electromagnetic simulations using machine learning,” IEEE Antennas Wireless Propag. Lett., vol. 18, no. 11, pp. 2264–2266, Nov. 2019. View More

Ö. Ergül and L. Gürel, “Rigorous analysis of doublenegative materials with the multilevel fast multipole algorithm,” ACES J., vol. 27, no. 2, pp. 161–168, Feb. 2012. View More

Ö. Ergül and L. Gürel, “Efficient solution of the electric and magnetic current combinedfield integral equation with the multilevel fast multipole algorithm and blockdiagonal preconditioning,” Radio Sci., vol. 44, RS6001, Nov. 2009. View More

Ö. Ergül and L. Gürel, “Comparison of integralequation formulations for the fast and accurate solution of scattering problems involving dielectric objects with the multilevel fast multipole algorithm,” IEEE Trans. Antennas Propag., vol. 57, no. 1, pp. 176–187, Jan. 2009. View More
Other Practical Studies

G. Karaova and Ö. Ergül, “Design, fabrication, and measurement of efficient beamshaping reflectors for 5G applications,” IEEE Trans. Antennas Propag., vol. 70, no. 12, pp. 11335–11343, Dec. 2022. View More

E. Çetin, M. B. Şahin, and Ö. Ergül, “Numerical study of chipless tags for radiofrequencyidentification (RFID) applications,” Advanced Electromagnetics, vol. 8, no. 2, pp. 10–17, Feb. 2019. View More

B. Karaosmanoğlu, S. Küçük, and Ö. Ergül, “Finetuning snowflake fractal antennas,” Int. J. Numer. Model., vol. 30, no. 6, e2212, Nov./Dec. 2017. View More

Ö. Ergül, A. ArslanErgül, and L. Gürel, “Computational study of scattering from healthy and diseased red blood cells,” J. Biomed. Opt., vol. 15, no. 4, 0450041–0450048, Jul./Aug. 2010. View More

Ö. Ergül and L. Gürel, “Nonplanar trapezoidal tooth logperiodic antennas: design and electromagnetic modeling,” Radio Sci., vol. 40, RS5010, Oct. 2005. View More