Electrical and Information Technology

Faculty of Engineering, LTH

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Rikard Gannedahl designed novel radio circuits for 5G and 6G communication


Rikard Gannedahl

Title of thesis: Frequency Generation and Baseband Filters for mm-Wave 5G and 6G Transceivers

Link to thesis in Lund University Research Portal.

Defence: Thursday May 30th, 09:15, room E:1406.
Zoom link.  Zoom ID: 66635753300.

Describe your research in a popular science way

My research has focused on designing radio circuits for 5G and 6G communication operating at the so-called mm-wave frequencies, that is, frequencies between 30 and 300 GHz. In previous generations (4G and earlier), the frequencies have been limited to 6 GHz or below. However, as our phone usage has shifted from calls and texting to much more data-intensive tasks like streaming and video calls, our bandwidth needs have dramatically increased. This has resulted in data traffic congestion at these sub-6-GHz frequencies, which is why 5G, and in the future 6G, has allowed for the use of mm-waves, enabling unprecedented bandwidths and data rates.

However, the use of mm-waves does not come without a cost. Radio circuits tend to perform significantly worse at these frequencies. Additionally, the path loss – the power that is lost when the signal is propagating from transmitter to receiver – is significantly higher at these frequencies. To overcome these issues, innovative circuit designs and system optimizations are necessary.

More specifically, my research has focused on two very important parts of a radio transceiver: frequency generation and baseband filters. The role of frequency generation is to generate a very stable and clean tone at a specific frequency. It is this frequency that determines which radio channel we will receive from/transmit to. We have designed two frequency generation circuits operating at mm-wave frequencies which have the capability to self-correct errors that arise during the manufacturing of the chips, resulting in very robust operation.

Baseband filters should filter out everything that is not the desired signal, which can be noise or other interfering signals. We have compared two types of filters to see which one is most suitable for the extremely wide bandwidths that are expected in 6G.

What made you want to pursue a PhD?

While it had always been in the back of my mind to do a PhD during my engineering studies – I mean, who doesn’t want to be able to put “Dr” as a title when booking a plane ticket? - it wasn’t until I did my Master’s thesis that I started to give it serious consideration. I began then to fully grasp the depth of this field and how much there was to learn, and a PhD seemed like the best opportunity to explore a wide range of subjects in the field and learn as much as possible.

I was also intrigued by the teaching aspect of the job, having worked as both a homework tutor after high school and a lab supervisor during my bachelor’s, and thoroughly enjoying both jobs.

What are your plans?

Having seen the academic side of our field for the last few years, I would now like to see it from an industry perspective. So, while nothing is finalized yet, I’m hoping to continue my career in circuit design with a company in the Lund-Malmö region.