8, February 2019

ESA Open Invitation to Tender AO9524
Open Date: 04/02/2019
Closing Date: 18/03/2019 13:00:00

Status: ISSUED
Reference Nr.: 18.1ET.15
Prog. Ref.: Technology Developme
Budget Ref.: E/0901-01 – Technology Developme
Tender Type: C
Price Range: > 500 KEURO
Products: Satellites & Probes / RF / Microwave Communication (Platform and Payloads) / Antennas / Omnidirectional, Helix, Horn, Parabolic, Phased Arrays / Platform vs Payload / Satellites & Probes / Payloads / Instruments / RF and microwave Instruments / Other (Scatterometers,..)
Techology Domains: Electromagnetic Technologies and Techniques / Antennas / Reflector and Lens Antennas / Electromagnetic Technologies and Techniques / Antennas / Array Antennas and Standalone Radiators
Establishment: ESTEC
Directorate: Directorate of Tech, Eng. & Quality
Department: Electrical Engineering Department
Division: RF Payloads & Technology Division
Contract Officer: Ferreol, Audrey
Industrial Policy Measure: N/A – Not apply
Last Update Date: 04/02/2019
Update Reason: Tender issue

Several SAR future Earth Observation missions requires large reflector antennas generating highly directive overlapped beams. This has been done so far with high power waveguide Beam Forming Networks including ferrite switches as implemented for Core H2O pre-developments.In this activity, it is proposed to investigate reflector antennas fed by overlapped subarrays. This represents an extremely promising concept for on-board SAR instruments. In fact, arrays based on overlapped subarrays permit generating highly directive beams enabling low spill over losses with the possibility of creating contiguous overlapped beams with a required cross-over level of typically 1 dB. A possible solution, recently developed for ESA Telecom applications, consists in overlapping contiguous feeds in a radiative way, i.e. without any bulky waveguide BeamForming Network. This overlapping can be achieved by using EBG materials or Fabry-Perot resonators placed in front of the feeding array; other configurations recently proposed may be considered as well. In thecase of Earth Observation missions, this overlapping may be significantly easier to achieve because contiguous beams should be activated sequentially in time with an associated simplification of the focal array architecture (especially in the filters needed to decouple contiguous feeds). Special attention shall be paid on the power handling needs.A first advantage of this new technology reflector, especially when the operational frequency is high, may be obtained replacing active phased arrays antennas with a reflector based antenna. A second advantage will be guaranteed feeding the reflector with an array organized in overlapped subarrays with the overlap done in a radiative way or in a guided way.The activity will be organized in 2 parts:1) design, analysis and optimization ofthe feeding array architecture;2) proof of concept. A breadboard will be designed and manufactured in order to demonstrate the capabilities of the new antenna architecture. The design of the feeding array will allow to extrapolate the performance of the entire antenna including the reflector.

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