Concept and application of millimeter-wave spectroscopy for subwavelength-sized particles

• Applicant: Professor Dr. Jan Hesselbarth
• Subject Area: Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 497853940

Scattering of electromagnetic waves, by a dielectric particle, in different spatial directions is determined by size, shape and permittivity of the particle. The objective of the proposed project is the experimental demonstration and theoretical investigation of a technique to detect simultaneously size, shape and permittivity of a small dielectric particle using millimeter waves. The particle size is supposedly much smaller than the free-space wavelength, therefore non-resonant Rayleigh-type scattering is anticipated. Besides scattering due to incidence of almost-planar waves of different polarization, incidence and scattering of a radially-polarized wave (Bessel beam) will be investigated. In view of a potential future application (of a similar system but scaled in frequency) for the characterization of a single biological cell in liquid, the characterization of a small scatterer, immersed in liquid at low dielectric contrast, will be explored. Experiments shall be conducted at frequencies around 60 GHz. Spheres and ellipsoids of different permittivity, with sizes smaller than one millimeter, will be used as scatterers.

• DFG Programme: Research Grants