PhD defence by Paolo Squadrito
27.11.2020 kl. 09.00 - 12.00
“Cm-Wave Antennas for Small Satellite Communications”
Boosted by the progress of modern technology a new class of miniaturized satellites is transforming the space industry. The scientific and industrial community, driven by the potential of this relatively new approach to space, is looking for new concepts or revisiting existing technologies and adapt them to the small form factor that characterizes this kind of satellites.
This Ph.D. thesis focuses on antennas research and development for small satellite communications.The introduction presents an overview of the space sector with special attention to the small satellite topic. This introductory part showcases the current state of the art in antenna systems for small satellites and a summary of several recent missions involving small satellites.
The first part presents a promising candidate for downlink communications in low earth orbit. This antenna can be considered as an alternative to small size array antennas based on the sequential rotation technique which are, to the best of the author's knowledge, currently used for downlink communications. By using a single element and exploiting the superposition of the radiated field a single antenna can match the gain of a 2X2 array. Since a relatively high gain can be obtained without using array configuration the design of a dual sense circularly polarized antenna is facilitated. Therefore, with the proposed design, it is possible to employ only one antenna rather than two (one for right-hand and one for left-hand circular polarization), with a clear advantage in terms of the area used on the aircraft. The second part presents a K-band linearly polarized, multilayer, integrated phased array antenna working in TX/RX mode for inter-satellite communication in low earth orbit. The antenna, based on printed circuit board technology, uses four monolithic microwave integrated circuits to achieve phase and amplitude control. The limited number of ICs in combination with the high gain required to achieve the desired communication rate over long distances posed several challenges and a compromise had to be made. The presented work is still in the early stage but since R&D of an active phased array, antennas is no trivial task this initial achievement could provide useful results for the industry and academia.
Associate Professor Gilberto Berardinelli, Aalborg University (chairman)
Professor Buon Kiong Lau, Lund University
Associate Professor Jorge Costa, Universidade de Lisboa Instituto de Telecomunicações
Professor Gert Frølund Pedersen, Aalborg University, Denmark
Associate Professor Shuai Zhang, Aalborg University, Denmark
Associate Professor Patrick Claus Friedrich Eggers, Aalborg University, Denmark
Free of charge
Antennas, Propagation and Millimetre-Wave Systems, Department of Electronic Systems
Online via Microsoft Teams (link will be sent to registered participants prior to the defence)
26.11.2020 kl. 12.00