First of all, I would like to thank Kaldi, the legendary Ethiopian goat herder whose unusually lively goats are said to have led him to coffee, as without coffee, much of this thesis would have been utterly impossible.
On reflection, however, thanking Kaldi first is rather unfair to the goats. It also overlooks whoever first thought of boiling water, the inventor of the cup, and the people who arranged for the coffee industry and my desk to become connected by a functioning supply chain. The desk itself raises further questions. Somebody had to invent carpentry. Before that, trees.
I can see this becoming a long section.
There is a difficulty with trying to give a complete account of one’s debts. Follow any useful thing backwards and eventually you are thanking most of civilisation, a butterfly in the Amazon and a favourable sequence of events in the early universe. All of them have in some way contributed to this book.
Having dealt, however inadequately, with the first 13 billion years, I would now like to start again, with those to whom I owe a more personal debt, though no less incalculable.
I would first like to thank my supervisors, Wout Joseph and Emmeric Tanghe, for the opportunity to pursue this doctorate, the time they devoted to our discussions and for reviewing various manuscripts. Wout, I appreciated every scribble of feedback you gave, no matter how illegible. I am especially grateful for the very large number of 17 conferences and meetings I was able to attend all around the world. I extend these thanks to Günter Vermeeren and my academic ‘godfather’ Sergei Shikhantsov. Sergei, both your software and hardware were foundational to this thesis, and working with you was inspiring. Thank you also, along with Olivier Caytan and Arno Moerman, for your help with the measurements, where, after years of simulated fields, you introduced me to a few real ones.
Thank you to Silvia, Marta, Gabriella, Joe, Shanshan, Martin and Mònica for the discussions within GOLIAT. Being part of a broader project around EMF, commissioned by the EU that can inform its policy, completely removes that solitary and inconsequential feeling a PhD can sometimes bring.
I also sincerely thank all my colleagues in WAVES and IDLab at Ghent University–imec. I will tactfully avoid listing you in an order that might receive more scrutiny than the thesis itself, because whether you are from the 5th or the 9th floor, international or Belgian, current or ex, you all mean a lot to me. However, Isabelle deserves particular recognition for her help with administration, a problem for which, as far as I can tell, no closed-form solution exists. Thank you Alessandro Biondi for filing a patent on our behalf, a considerable effort.
I am grateful to the people I met at conferences and meetings, particularly my friends Fariba, Cindy, Ninad, Javier, Carina, Pablo, and Erdem, Bryn, Marisa and Niels Kuster at Zurich43; and Adriana, Hamed, Nicolas, Valentin, Nekane, Irina and Martin at Swiss TPH.
I thank the members of the examination board, Azadeh Peyman, Claude Oestges, Luc Dupré, David Plets and Patrick De Baets, for being brave enough to read the manuscript past the acknowledgements and providing valuable feedback. I also thank the anonymous reviewers for their constructive criticism, particularly Reviewer 2, whose identity remains unknown but whose influence on my life has been considerable.
Parts of this research were supported by the European Union’s Horizon Europe programme through GOLIAT (grant 101057262), the European Research Council through ATTO: A New Concept for Ultra-high Capacity Wireless Networks (grant 695495), and Methusalem through SHAPE: Next Generation Wireless Networks.
To my friends, including those I know through music, school and the 60ies, thank you for your company over these years. A particular thank you to Robin, Michiel, Jeroen & Hannelore, and all the people I have made music with through GUHO and Aeolus Ganda, even if the exposure to acoustic waves from one specific trumpeter was, at times, over the safe limits.
To my family, especially my parents and my sister, thank you for patiently accepting that ‘almost finished’ is not, in fact, close to finished at all. Thank you, along with Vlekje and Archie, for always making me glad I came home for the weekend, however many deadlines were waiting.
Finally, to the beautiful girl on the 9th floor, Carolina. I came to find answers to questions about the world, and somewhere in that world, I found you. Of everything this doctorate has brought me, meeting you is by far what I am most grateful for. I have no doubt that you will become a brilliant doctor, and I cannot wait to discover what the years ahead have in store for us.
Robin Wydaeghe, Ghent, October 2026