Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - LAA-THz-CC (Lens Antenna Arrays for Coherent THz Cameras )

Teaser

The THz region was limited to applications in radio astronomy and space science. In recent years, THz systems have expanded into many more areas of science, defence, security, and non-destructive industrial applications. Microwave based THz cameras have demonstrated the...

Summary

The THz region was limited to applications in radio astronomy and space science. In recent years, THz systems have expanded into many more areas of science, defence, security, and non-destructive industrial applications. Microwave based THz cameras have demonstrated the highest sensitivity at large distances. However, their current state of the art is comparable to the first analog photographic cameras characterized by long exposition times. Two fundamental problems have to be addressed to change this situation: technologically, there is the lack of integrated coherent arrays with high power and sensitivity; and theoretically, a field representation to characterize analytically these systems is missing.

I propose to tackle the technological problem by exploiting the coherency between small antenna arrays coupled to actuated lenses to overcome the sensitivity problem and achieve instantaneous refocusing (i.e. zooming). The proposed antenna technology is based on a recent breakthrough that I pioneered: micro-lenses excited by leaky waves with seamless integration in silicon technology. This antenna enables the fabrication of large fly’s eye cameras in just two wafers, and promises one order of magnitude better scanning performances than previous solutions. An analytical model to investigate the electromagnetic response of coherent THz arrays is the enabling tool for optimizing the camera performances. I will develop this tool by combining advance spectral antenna techniques with coherent
Fourier Optics. This model will not only be used in new beamforming techniques, but also for the characterization of future THz telecommunication links.

This project will make the first significant strides in developing the next generation of coherent THz imaging cameras. The outcome of this project will be instrumental in pushing today\'s costly THz niche applications into the main stream, and possibly pole vault THz systems into the 21st century communication society.

Work performed

Modelling of Quasi-Optical Systems:

Most of the THz imaging cameras nowadays rely on quasi-optical systems for achieving beamforming. An accurate and fast analysis of such systems, which are extremely large in terms of the wavelength and rely on very low levels of power and sensitivity, is of great importance. During this phase, we have validated with excellent agreement several THz multibeam antennas based on quasi-optical system with measurements of both patterns and efficiencies. We have also developed a quasi-analytical technique based on a plane wave expansion via the use of a Fourier Optics approach for the design of future THz focal plane lens arrays coupled to a cascade of quasi-optical components.

Fly’s Eye Antenna System for Future Tbps Wireless Communications:

The requirements for wireless data streaming are exponentially increasing today with nearly everyone possessing a smartphone or similar device packed with every sort of app to stay in contact and share one’s life with the world. Nowadays, these demands cannot be met in densely populated environments such a sport stadium. We have envisioned a solution that can provide 200 times more data rates by using a base station made of fly’s eye lenses at THz that can make 80000 user connections simultaneously.

Final results

The use of a Fourier Optics approach for co-analyzing quasi-optical systems together with the detectors has been applied, for the first time, to THz imaging cameras. The proposed approach leads to one order faster computation time that standard techniques. Moreover since it is based on having the fields expanded in terms of plane waves gives the designer a clear physical picture of the problem. Once the proposed theory is finalized, a free accessible tool will be provided to other researchers working in the field.

The target of this ERC is to develop coherent systems with multiple directive beams by using fly’s eye lens arrays. We have done a white paper in the international antenna conferences to show that this technology can provide order of magnitude higher data rates than current cellular and WIFI networks. The targeted scenario has been a sport stadium and the operating frequency high in order to be applicable to more futuristic 6G networks.