Public defence, Radio Science and Engineering, MSc (Tech) Jan Bergman

Title of the thesis: Advancements in antenna arrays for frequencies beyond 100 GHz.

Thesis defender: Jan Bergman
Opponent: Prof. Rob Maaskant, Chalmers University of Technology, Sweden
Custos: Prof. Ville Viikari, Aalto University School of Electrical Engineering 

In wireless applications, a higher operating frequency leads to higher performance. Today, most systems operate at frequencies below 6 GHz, due to the relatively ease and affordability of implementation at those frequencies. This thesis aims to make antenna design at 100 GHz just as easy.

The thesis splits this challenge into three main topics. Firstly, the possibility of only connecting some of the antennas in a large antenna array to a signal source is studied. This results in some of the antennas remaining disconnected. These so-called parasitic elements are driven by the fields radiated by the other elements; thus, still contributing to the performance of the array. Because these parasitic elements do not require any components related to feeding them, designing the array becomes easier and much cheaper.

Secondly, the applicability of modern manufacturing methods, such as 3D-printing, for manufacturing antennas at 100 GHz is evaluated. A high operating frequency results in physically small antennas, being only around 1 mm in size at 100 GHz. Traditionally, manufacturing these has required accurate but complex and expensive methods. This thesis shows that manufacturing these antennas can be much cheaper and quicker when utilizing modern methods.

The third and final topic is the co-design of antennas and integrated circuits. Every wireless system requires integrated circuit components, but their presence can affect the performance of the antennas, especially at higher frequencies. To account for, and even benefit from these effects, the antennas and the integrated circuits should be designed while considering the effect they have on each other. In this thesis, the importance of such co-design is demonstrated by designing and manufacturing a 100-GHz integrated radio receiver, which includes both the antennas and integrated circuit components.

Through these three topics, this thesis builds the foundation for a future where every-day applications can benefit from frequencies beyond 100 GHz.

Key words: antenna array, antenna–IC co-design, aperture-coupled antenna, millimeter wave, parasitic element, Vivaldi antenna

Thesis available for public display 7 days prior to the defence at Aalto University's public display page.