Internal Research Fellow (Post Doc) in Innovative Multibeam Active Antennas and Beamforming Networks

Internal Research Fellowship Opportunity in the Directorate of Technology, Engineering and Quality.

ESA is an equal opportunity employer, committed to achieving diversity within the workforce and creating an inclusive working environment. For this purpose, we welcome applications from all qualified candidates irrespective of gender, sexual orientation, ethnicity, beliefs, age, disability or other characteristics. Applications from women are encouraged.

This post is classified F2 on the Coordinated Organisations’ salary scale .

Location
ESTEC, Noordwijk, Netherlands  

The Radio Frequency Payloads and Technology Division (TEC-EF) is responsible for RF payloads, instruments and technologies for space and ground applications, including all equipment with a radio frequency space/ground interface and the associated laboratories. The Division supports the definition, specification and development/procurement of laboratories, either for ESA projects and technology programmes or external customers.

Within the TEC-EF Division, the domains covered by the Antenna and (Sub)-Millimeter Wave Section (TEC-EFA) include standalone radiators, reflector antennas and array (active or passive) antennas. The Section addresses system aspects as well as interference effects between antennas and the spacecraft structure, covering the 400 MHz to 5 THz range of the frequency spectrum. The Section also provides technical support for ESA projects in Earth observation, telecommunications, navigation and science, including “in-house” design and trade-offs for technology developments. Furthermore, the Section supports all antenna development stages from the early RF design and analysis up to test and verification. When appropriate, the measurements are performed in the ESTEC antenna test facilities that are managed by the section.

      You are encouraged to visit the ESA website: https://www.esa.int/

The main objective of this Research Fellowship consists in investigating innovative multibeam active antennas and beamforming networks for emerging telecommunications missions, covering some of the following topics in particular:

• array antennas exploiting different types of array layouts (Cartesian, triangular, irregular, etc.);
• architectures compatible with hybrid analogue/digital beamforming;
• architectures based on overlapped or interleaved subarrays; 
• architectures compatible with distributed apertures and satellite swarms;
• architectures suitable for implementing pragmatic MIMO solutions for 5G, 6G etc.

Some of the active antenna configurations are of interest for GEO satellite missions, while others are of interest for MEO and LEO satellite missions.

On array antennas exploiting different types of array layouts
After two decades of R&D, mainly promoted by the European Space Agency, unconventional antenna arrays have been successfully deployed in space by companies from outside Europe (such as mPower by Boeing and Starlink). The main advantages offered by irregular arrays include the following: a) the sidelobe level may be modified by acting on the density tapering with or without using amplitude and phase excitations; b) the number of elements for a given aperture can be reduced with a limited influence on the beamwidth; c) the aperiodic spatial distribution allows the spreading and controlling of the energy of grating lobes; d) thanks to the reduction of the level of grating lobes, the array is suitable for wideband applications; and e) mutual coupling becomes less problematic for unequal inter-element spacings.

On hybrid beamforming solutions
The cost and complexity of active antennas is determined by the contribution of beamforming networks. Beamforming network complexity grows with the product (number of beams) x (number of radiating elements). When both contributions exceed a few hundred, the overall complexity becomes prohibitive. Hybrid beamforming schemes, exploiting a two-level analogue/digital beamforming architecture, have been proposed by European industry to simplify spaceborne active antennas by reducing the number of control points, components, architecture complexity and power consumption. At radiating element level, the signal is adjusted by analogue phase shifters. The beamforming is therefore performed in two or more stages. Until now, hybrid beamforming schemes have found limited application for spaceborne active antennas because of the difficulties involved in reducing and controlling grating lobes. Several interesting and challenging hybrid beamforming solutions based on overlapped and/or interleaved subarrays could be further developed as part of this Research Fellowship.

On pragmatic MIMO solutions
The fundamental idea behind MIMO is the exploitation of array antenna technologies for the base station to serve a multitude of users. MIMO has become increasingly important in the latest generation of wireless networks, and Massive MIMO is the key enabling technology of fifth generation (5G) networks. The exploitation of M-MIMO in the forward link of satellite systems needs large onboard active arrays – which are the subject of several ongoing industry developments. The adoption of conventional Massive MIMO for SatComs has a number of practical issues and simplifying approaches relying only on the information of the user location have been proposed. In recent ESA contributions, a pragmatic M-MIMO approach has been outlined, obtaining significant simplifications.
As part of this Research Fellowship, several pragmatic MIMO solutions could be further developed, adapted to 5G and 6G scenarios and co-designed with sparse and hybrid array architectures.

Knowledge relevant to the field of research

Research/publication record

Ability to conduct research autonomously

Breadth of exposure coming from past and/or current research/activities

Ability to gather and share relevant information

Result Orientation
Operational Efficiency
Fostering Cooperation
Relationship Management
Continuous Improvement
Forward Thinking 

You should have recently completed, or be close to completion of a PhD in a related technical or scientific discipline. Preference  will  be  given  to applications submitted by candidates within  five  years of receiving their PhD.

In particular for this position, the following is required: PhD in the antennas or electromagnetic domain.

You should also have:

• comprehensive background in electromagnetic wave theory is required for this post.
• general interest in space and space research.
• general interest in space and space research

The working languages of the Agency are English and French. A good knowledge of one of these is required. Knowledge of another Member State language would be an asset.     

Other information

For behavioural competencies expected from ESA staff in general, please refer to the ESA Competency Framework .

For further information on the Internal Research Fellowship Programme please visit: Internal Research Fellowship

The Agency may require applicants to undergo selection tests.

In addition to your CV and your motivation letter, please add your proposal of no more than 5 pages outlining your proposed research in the "additional documents" field of the "application information" section.

At the Agency we value diversity and we welcome people with disabilities.  Whenever possible, we seek to accommodate individuals with disabilities by providing the necessary support at the workplace.  The Human Resources Department can also provide assistance during the recruitment process. If you would like to discuss this further please contact us at [email protected] .

--------------------------------------------------------------------------------------------------------------------------------------------------

Please note that applications are only considered from nationals of one of the following States: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, and the United Kingdom. Nationals from Latvia, Lithuania, Slovakia and Slovenia, as Associate Member States, or Canada as a Cooperating State, can apply as well as those from Bulgaria, Croatia and Cyprus as European Cooperating States (ECS).

According to the ESA Convention, the recruitment of staff must take into account an adequate distribution of posts among nationals of the ESA Member States*. When short-listing for an interview, priority will first be given to candidates from under-represented Member States *.

In accordance with the European Space Agency’s security procedures and as part of the selection process, successful candidates will be required to undergo basic screening before appointment conducted by an external background screening service. 

*Member States, Associate Members or Cooperating States.