High-speed wireless communication and automotive radars are two applications with huge social and market potentials that can be revolutionized by the development of high frequency (sub-terahertz) technology. Unprecedented communication speeds and image resolutions are needed for these applications, and such requirements can be fulfilled only by shifting the operation of transmitting and receiving devices to higher frequencies. However, technological limitations need to be overcome in order to exploit the full potential of sub-terahertz technology: the poor performance of on-chip antennas is nowadays the major bottleneck in converting the electrical signals (on-chip) into radiated ones (off-chip).
A breakthrough concept was introduced in the framework of the ERC AAATSI project from the principal investigator to enable efficient radiation from chip. It consists of placing artificial dielectric layers (ADLs) on top of the radiating element. It was demonstrated that such add-on engineered dielectric material can greatly enhance the emitting performance of on-chip antennas. By overcoming the fundamental limitation of integrated antennas, AD layers have high potential to become a “standard” component in all future car-safety and wireless communication devices.
The AD-HOC project aimed at developing a fabrication process for ADLs at terahertz (THz) and sub-THz frequencies, compatible with integrated circuit processing and suitable for future technological scale-up. The vision was to create commercially viable ADL to be used as an independent add-on component to enhance the performance of antennas already available on the market. During the project, many challenges were faced to bring the ADL a step closer toward the market: reducing process complexity, increasing the reproducibility and yield, while reducing fabrication costs. The processes necessary to micro-fabricate AD layers were optimized with the goal of achieving reliable manufacturing, while offering design flexibility at low costs. The investigation of different materials identified low-loss polymers as good candidate for realizing reliable and resistant ADLs.
