Lionel Tombakdjian
About
Passionate about space and electronics since my youngest age, I’ve always loved to fix/create things such as an Arduino controlled chick incubator. After completing my Master I wanted to specialize my skills with a space related subject which the subject of my PhD thesis.
RF & Antenna Research Engineer
After finishing my Fundamental Physics Bachelor's degree, I decided to specialize in Electronics and Telecommunications through the ESTeL Master's program at Université Côte d'Azur. While I was ready to work as an Embedded System Engineer after completing the Master's, I was also still eager to learn more, which is why I decided to pursue my academic journey as a PhD student.
My PhD focused on three domains I love: Antennas, Space, and 3D printing. Specifically, the objective of my PhD was to develop multibeam antennas for satellite navigation services using advanced circuits and 3D-printed RF lenses.
Before completing my PhD, I was contacted by multiple companies in the space sector to collaborate on a response to a European Space Agency (ESA) invitation to tender. This led to a one-year Post-doctoral fellowship. During this year, my goal is to continue the further development of a 3D-printed lens antenna for LEO satellite constellation use cases.
- Birthday: 6 December 1996
- City: Nice, France
- Website: lionel.tombakdjian.com
- Degree: PhD
- Citizenship French
- LinkedIn: linkedin.com/in/ltombakdjian
- Current employment: Postdoctoral Research Eng. at Université Côte d'Azur
Skills
I am a versatile engineer with a strong foundation in RF and antenna design, complemented by hands-on experience in electronic circuit design, embedded systems development, and basic web and server administration. I am also well-acquainted with laboratory work, with regular use of standard RF measurement instruments such as vector network analyzers (VNA), spectrum analyzers, signal generators, and oscilloscopes. This multidisciplinary background allows me to contribute effectively across both hardware and software domains.
Resume
Sumary
Lionel Tombakdjian
I am a versatile researcher and engineer specializing in RF and antenna design, with additional expertise in circuit development, embedded systems, and hands-on lab work, complemented by practical skills in server and web administration.
Education
PhD in Electronics
2021 - 2024
Cenre National de la Recherche Scientifique (CNRS), France
Multibeam Beamforming antennas for Navigation
Master of Science
2019 - 2021
Université Côte d'Azur, France
Electronic and Telecommunication
Bachelor of Science
2015 - 2019
Université Côte d'Azur, France
Fundamental Physics
Professional Experience
RF R&D Eng. - PostDoc
2025 - Present
LEAT - Université Côte d'Azur (UniCA)
ESA NAVISP funded project with Thales Alenia Space. The objective is to receive Ku-band signals from LEO satellites and compute a position based on it. My missions include all the hardware design (antenna + RF chain):
- 3D printed 32 beams Luneburg lens with ceramic material
- Conformal array antenna (alternative solution)
- 32:4 switch matrix @12GHz to get 4 simultaneous beams from 32 available
- 4CH coherent downconverter unit
PhD student
2021 - 2024
CNRS, UMR7248 LEAT
ESA funded project to develop multi-beam antennas for navigation purposes (GNSS and Signal of Opportunity: SoOp).3 antennas delivered to ESA during the PhD:- L-band phased array 64 elements, including the design and fabrication of all the components:
- Unitary element (L1/L5, RHCP/LHCP) thanks to a 3D printed substrate enhancing the bandwidth.
- Very modular beamformer with filter, LNA, Phase shifting, combiner (Wilkinson divider) stages including the firmware development to create beams with a simple Python API.
- L-band 3D printed Luneburg lens using standard 3D printing technologies (10 dBi gain, 29cm diameter)
- Modified geometry of the lens to accommodate for a source array (16 antenna elements) enabling large coverage with simultaneous beams operation.
- Design of a 16Ch low cost GNSS receiver/logger.
- Ku-band (10,5-12,5GHz) 3D printed Luneburg lens antenna to use as signal of opportunity for navigation with LEO satellites.
- Optimization of the source array design to maximize coverage while being completely flat (16 sources).
- Design of a low cost multichannel downconverter by hacking affordable LNBs.
- Side projects during the PhD:
- Design of different kind of radiating elements for 5G mmWave (28GHz): Dipole antenna array, linear and rectangular patch antenna array with dual polarization, 3D printed ceramic DRA (Dielectric Resonator Antenna).
- 3D printed material characterization with 2 methods: waveguide S-parameters and visit at ESYCOM (Université Gustave Eiffel) to use a custom made coaxial measurement method.
- Development of an automated measurement protocol using a R&S ZNA67 (SCPI) and a R&S ATS800 CATR test system for directive antennas.
- IMS2022 conference demonstration preparation for an innovative EVM (Error Vector Magnitude) measurement method.
Visiting Expert
2024 April-July
ESTEC, European Space Agency (ESA), The Netherlands
I was invited as a visiting expert in the TEC-SEI section for a 4 months period. I was able to test all the antennas and RF hardware developed during the thesis with both lab equipment and real-world signals using GNSS receivers and SDRs (Software Defined Radios).
- Beamforming measurements of the lens with GNSS receivers.
- Beamforming experiments with Spirent simulators to counter GNSS jamming.
- Starlink signal reception using the developed lens and multiple SDRs (Ettus/NI with GNURadio).
R&D Eng. - apprenticeship
2020 - 2021
Abeeway, Sophia-Antipolis France
- Development of a low-power geolocation module for IoT in partnership with Murata. Hardware and firmware evaluation of modules and evaluation boards.
- Design of circuits and antennas for a low-power GPS tracker (LoRa 868/915 MHz and BLE 2.4 GHz). RF measurements of Abeeway products using an MVG Starlab station for development and certification.
Contact
You can contact me by connecting on LinkedIn or by filling this form.
Address
Nice, France