Research

• Topological Electromagnetics

I develop a rigorous mathematical framework for topological electromagnetics in anisotropic, gyrotropic continuum media. My recent work formulates the Berry phase, Berry curvature, and Chern number using differential geometry and surface wave theory, providing a systematic characterization of bulk-edge correspondence in continuum materials. While magnetized plasmas serve as a primary case study, the framework applies broadly to anisotropic, dispersive, and gyrotropic electromagnetic media.

In parallel, I lead experimental efforts to validate theoretical predictions. This includes a pioneering demonstration of topologically protected unidirectional surface waves at a gaseous magnetized plasma–metal interface, confirming theoretical predictions using full-wave measurements in the Voigt configuration.

Related Papers:

H. M. Bernety and M. A. Cappelli, “Topological Electromagnetics in Anisotropic Media: Theory and Application to Magnetized Plasmas,” submitted to IEEE TAP, Jul. 2025.

H. M. Bernety, Declan Murphy Zink, Daniel Piriaei, and Mark A Cappelli, “Experimental detection of topological surface waves at a magnetized plasma interface in the Voigt configuration,” Applied Physics Letters, 124(4), 2024.

H. M. Bernety and Mark A Cappelli, “An electromagnetic scattering approach to identifying topological and non-topological unidirectional edge states at gyrotropic plasma interfaces,”  Journal of Applied Physics, 133(10), 2023. 

• Wave-Matter Interactions in Time-Varying Media and Photonic Time Crystals

I develop analytical models for electromagnetic wave propagation in time-varying media, focusing on frequency conversion in linear, spatially unbounded systems. These models show how temporal modulation drives energy exchange and spectral transformation, independent of spatial boundaries. I also extend this framework to finite time blocks, deriving closed-form predictions of transmitted fields. Together, these efforts provide a powerful framework for analyzing and optimizing time-varying media in experimentally relevant scenarios.  

Magnetized and linearly time-varying plasmas serve as the primary testbed for this work, but the underlying principles are general to a broad class of time-modulated continuum media.

Related Papers:

H. M. Bernety and M. A. Cappelli, “A Closed-Form Solution for Electromagnetic Wave Propagation in Spatially Unbounded, Linear Time-Varying Plasmas,” IEEE Antennas and Wireless Propagation Letters, vol. 24, no. 5, pp. 1163–1167, May 2025.

H. M. Bernety and Mark A Cappelli, “A simple model for frequency up-conversion in linear time-variant gaseous plasmas,” Physics of Plasmas, 31(10), 2024.

• Reconfigurable and Nonreciprocal RF and Microwave Devices 

I design, model, and experimentally demonstrate reconfigurable electromagnetic devices that exploit nonreciprocity and gyrotropy for advanced RF and microwave functionality. My work includes the development of circulators and unidirectional waveguides using magnetized plasmas as a tunable medium, offering compact and efficient alternatives to ferrite-based components.

While plasmas provide a versatile testbed, the underlying principles extend to gyrotropic and anisotropic materials with engineered electromagnetic responses. This approach enables the advancement and commercialization of microwave devices, development of tunable antenna structures, and new directions in metamaterial and photonic crystal design.

Related Papers:

Mark A Cappelli, H. M. Bernety, Daniel Sun, Luc Houriez, and Benjamin Wang, “Tunable non-reciprocal waveguide using spoof plasmon polariton coupling to a gaseous magnetoplasmon,”  Optics Letters, 48(14):3725–3728, 2023.

H. M. Bernety, Luc S Houriez, Jesse A Rodríguez, Benjamin Wang, and Mark A Cappelli, “A tunable microwave circulator based on a magnetized plasma as an active gyrotropic element,” Physics of Plasmas, 29(11):112114, 2022.

H. M. Bernety, L. S. Houriez, J. A. Rodr´ıguez, B. Wang, and M. A. Cappelli, “A Characterization of Plasma Properties of a Heterogeneous Magnetized Low Pressure Discharge Column,” AIP Advances, vol. 12, no. 11, p. 115220, Nov. 2022.  [Featured Article]

L. S. Houriez, H. M. Bernety, J. A. Rodriguez, B. Wang, and M. A. Cappelli, “Experimental Study of Electromagnetic Wave Scattering from a Gyrotropic Gaseous Plasma Column,” Applied Physics Letters, vol. 120, no. 22, p. 223101, Jun. 2022.

• Real-Time Beamforming for Arbitrarily Positioned, Oriented, and Polarized Arrays

During my PhD, I independently developed analytical frameworks for real-time beamforming in arbitrarily positioned, oriented, and polarized radiating systems — problems that typically rely on slow, iterative numerical optimization. I introduced the Constructive Analytical Phasing (CAP) and Generalized Analytical Phasing (GAP) methods, which provide closed-form solutions for excitation phases in radiators and scatterers with arbitrary far-field polarization. These formulations generalize pattern synthesis to geometrically and polarization-diverse arrays, enabling non-iterative beam steering in real time.

This work extends beyond conventional antenna arrays to include random metasurfaces and inhomogeneous scatterer arrays, allowing deterministic phasing for conformal, wearable, and drone-based platforms. I also introduced the Reduced-Order Numerical Phasing (RONP) method, which compresses the optimization search space from N dimensions to two real parameters, achieving near-optimal phasing accuracy for large arrays with orders-of-magnitude faster computation.

This research was recognized with a Finalist Award in the Student Paper Competition at the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting.

Related Papers:

H. M. Bernety and D. Schurig, “Fast beamforming for dynamic, randomly-configured antenna arrays and metamaterials,” IEEE Antennas and Wireless Propagation Letters, vol. 19, no. 12, pp. 2087–2091, Dec. 2020.

H. M. Bernety and D. Schurig, “How to phase antenna arrays and metasurfaces of arbitrarily oriented and polarized elements?” IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, pp. 2189–2190, Jul. 2019. [Finalist Award]

H. M. Bernety, S. Venkatesh, and D. Schurig, “Analytical phasing of arbitrarily oriented arrays using a fast, analytical far-field calculation method,” IEEE Transactions on Antennas and Propagation, vol. 66, no. 6, pp. 2911–2922, Jun. 2018.

• Elliptical Metasurface Cloaks for Low-Interference Communications

I developed an analytical framework to compute electromagnetic scattering from metallic and dielectric elliptical cylinders and strips. Building on this foundation, I introduced a mantle cloaking technique for elliptical geometries using confocal elliptical metasurfaces, implemented with periodic metallic inclusions at microwave frequencies and graphene nanostructures at low terahertz bands. This approach enables metamaterial-based suppression of mutual coupling between closely spaced antennas—both in free space and printed platforms—while preserving their radiation patterns. This concept was later extended to wideband systems and experimentally verified in collaboration with external groups. 

This research was recognized with an Honorable Mention Award in the Student Paper Competition at the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting.

Related Papers:

H. M. Bernety, A. B. Yakovlev, H. Skinner, S-Y. Suh, and A. Alu, “Decoupling and cloaking of interleaved phased antenna arrays using elliptical metasurfaces,” IEEE Transactions on Antennas and Propagation, vol. 68, no.6, pp. 4997–5002, Jun. 2020.

G. Moreno, A. B. Yakovlev, H. M. Bernety, D. H. Werner, H. Xin, A. Monti, F. Bilotti, A. Alu, “Wideband elliptical metasurface cloaks in printed antenna technology,” IEEE Transactions on Antennas and Propagation, vol. 66, no. 7, pp. 3512–3525, Jul. 2018.

H. M. Bernety and A. B. Yakovlev, “Decoupling antennas in printed technology using elliptical metasurface cloaks,” Journal of Applied Physics, vol. 119, no. 1, p. 014904, Jan. 2016.

G. Moreno, H. M. Bernety, and A. B. Yakovlev, “Reduction of Mutual Coupling Between Strip Dipole Antennas at Terahertz Frequencies With an Elliptically Shaped Graphene Monolayer,” IEEE Antennas and Wireless Propagation Letter, vol.63, pp. 1533–1536, Dec. 2015.

H. M. Bernety and A. B. Yakovlev, “Cloaking of Single and Multiple Elliptical Cylinders and Strips with Confocal Elliptical Nanostructured Graphene Metasurface,” Journal of Physics: Condensed Matter, vol. 27, no. 18, p. 185304, Apr. 2015.

H. M. Bernety and A. B. Yakovlev, “Reduction of Mutual Coupling between Neighboring Strip Dipole Antennas Using Confocal Elliptical Metasurface Cloaks,” IEEE Transactions on Antennas and Propagation, vol. 63, no. 4, pp. 1554–1563, Apr. 2015.

H. M. Bernety and A. B. Yakovlev, “Cloaking of dielectric and metallic elliptical cylinders with a nanostructured graphene metasurface,” IEEE International Symposium on Antennas and Propagation, pp. 890–891, Jul. 2014. [Honorable Mention Award]

• Helmet-Based FMCW Radar: Performance Analysis and Signal Enhancement 

I developed a probabilistic impact prediction model based on Monte Carlo simulations of helmet-mounted FMCW radar systems, aimed at mitigating head injuries in contact sports such as American football. I also designed and analyzed geodesic-polyhedral, omnidirectional retroreflectors to enhance the monostatic radar cross section of otherwise weakly scattering surfaces. These retroreflectors can be conformally mounted on helmets and have potential applications in collision-avoidance systems in sports and other high-risk environments.

This research was recognized with a Finalist Award in the Student Paper Competition at the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting.

Related Papers:

H. M. Bernety and D. Schurig, “Omnidirectional retroreflective surface using geodesic polyhedra,” AIP Advances, vol. 10, no. 2, p. 025302, Feb. 2020.

H. M. Bernety, S. Venkatesh, and D. Schurig, “Performance analysis of a helmet-based radar system for impact prediction,” IEEE Access, vol. 6, pp. 75124–75131, Dec. 2018.

H. M. Bernety and D. Schurig, “Analysis of a helmet-based FMCW radar for impact prediction,” IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, pp. 1379–1380, Jul. 2017. [Finalist Award]

• Electromagnetic Field focusing for Implantable Medical Devices

I introduced a passive electromagnetic focusing device composed of soft, conductive lines extruded directly into tissue to enable wireless powering and telemetry of medical implants. This device guides and concentrates far-field energy with high spatial precision, achieving strong enhancement in localized power delivery. The design is compatible with both linear and circular polarizations, tunable in depth, and suitable for in vivo fabrication using thermally activated biocompatible polymers—offering a scalable path toward safe, efficient, and implant-friendly telemetry systems. 

Related Papers:

H. M. Bernety, H. Zhang, D. Schurig, and C. Furse, “Field focusing for implantable medical devices,” IEEE Journal of Electromagnetics, RF, and Microwaves in Medicine and Biology, vol. 4, no.4, pp. 273–278, Dec. 2020.

H. M. Bernety, H. Zhang, D. Schurig, and C. Furse, “Comparison of passive 2-D and 3-D ring arrays for medical telemetry focusing,” IEEE Antennas and Wireless Propagation Letters, vol. 18, no.6, pp. 1189–1193, Jun. 2019.