Exceptional students lie at the heart of a research group. If you: (i) Have a passion for physics, applied electromagnetics and related fields, (ii) Are willing to work very hard when necessary, and (iii) Can think and work both independently and in a small group environment, please seriously consider joining my research group. In particular, I am looking for students with the interest and skills in some the following technical areas.

  • Electromagnetics
  • Antennas
  • RF Circuits
  • Microwave / mm-wave / terahertz-wave
  • Metamaterials or Metasurfaces
  • Wave optics

I look forward to welcome PhD students to the group; students looking to pursue shorter term research are welcomed to consider the M.Sc degree. Please check the Graduate_Studies_Webpage for the Electronic Engineering Department at CityU for the applicaiton dates and detailed degree information. I also invite interested students to contact me at alex DOT mh DOT wong AT cityu.edu.hk.

At the City University of Hong Kong and the State_Key_Laboratory_of_Terahertz_and_Millimeter_Waves, you will have access to cutting edge experimental facilities and learn under the guidance of world-class professors in applied electromagnetics research and education. You will also live and learn in the diverse Hong Kong metropolis which runs with a unique mix of Eastern and Western cultures and lifestyles. Successful Master and PhD degree applicants will receive sufficient stipend to cover tuition and living expenses for the duration of the degree.

Current Projects

Discrete Huygens’ Metasurfaces

A Huygens’ metasurface is an artificially engineered surface which provides sufficient electric and magnetic response to turn an incident electromagnetic wave into a desired reflected and/or transmitted wave. Up till now, most metasurfaces are designed as a surface with continuous variations in their electromagnetic properties. However, in recent works, we have shown that coarsely discretized metasurface elements may actually make better metasurfaces than smoothly discretized ones. In some cases, using coarsely discretized elements can improve the metasurface performance and reduce its fabrication tolerance at the same time. An ongoing project will be charted to demonstrate the simple fabrication of this discretized Huygens’ metasurface at terahertz and optical frequencies: at these frequencies, it is highly non-trivial to fabricate and align traditional metasurface elements due to their small sizes. Successful demonstrations showing simplified fabrication and the versatile applicability of the discretized Huygens’ metasurface should pave way towards building practical high-frequency electromagnetic surfaces, which can be a very powerful electromagnetic wave processing tool, usable in beamforming, switching / routing, imaging and display engineering.

Huygens’ Box

A lot of work has been performed on the design and implementation of planar metasurfaces. However, much greater possibilities await us when we wrap a metasurface around an area of interestc. Indeed, when one surrounds an area with an active metasurface that generates both electric and magnetic dipoles, one can generate an arbitrary waveform inside that area, as predicted from the fundamental electromagnetic equivalence principle. Very recently, we have performed experiment using what we call a Huygens’ box: a rectangular metallic cavity lined by a simple active Huygens’ metasurface. By properly exciting the Huygens’ metasurface, we demonstrated the generation of plane waves that travel in arbitrary directions within a rectangular metallic box, but disappear once they reach the edge of the box, with no reflections. Building on this, we intend on generating arbitrary waveforms inside an enclosed area by superimposing the aforementioned travelling waves. If successful, this technology may find impactful applications in imaging and therapy based on electromagnetic waves, a novel generation of antennas, and refined point-to-point indoor wireless propagation, just to name a few.