European Space Agency
European Space Agency
The objective of this activity is to explore the use of additive manufacturing for the development of BFN products for use in telecom multi-beam mission payloads.
The activity comprises:
The main advantages of the designed breadboard with respect to the equivalent BFN manufactured using conventional machining are the following:
In this activity, a breadboard containing 5 TX and 5 RX BFN elements is designed, manufactured (using Selective Layer Melting technology) and tested. Each element contains a hybrid E-H divider, so it is a 5-port device from an RF point of view. The common port is a standard rectangular waveguide (WR51 for TX and WR34 for RX), while the other ports are low-profile waveguides to ensure compactness. The TX and RX elements are interleaved following a complex pattern to ensure further miniaturization of the overall footprint.
The breadboard is designed specially for additive manufacturing and – more specifically – for vertical 3D-printing using the SLM technology, resulting in an all-metal, monolithic part. To this end, custom hexagonal waveguide sections have been used for the waveguide bends after the E-H divider. Transitions from hexagonal to low-profile rectangular waveguides are included in the design to ensure compatibility with the surrounding subsystems. Finally, a common bottom flange for all the BFN elements is designed to rigidify mechanically the part.
The Thales Alenia Space TX/RX Multiple Feed per Beam (MFB) solution offers a very miniaturised 4 access, dual-polarised TX/RX KISS feed combined with low cost, low loss, and large bandwidth beam forming networks.
These Quad MFB antennas provide high RF performances beams with only two reflectors. Each beam is generated by a cluster of 4 horns, some of them being shared with adjacent clusters to provide an adjacent beam (same frequency band, but opposite polarizations).
The mission is fulfilled by 2 antennas. The whole coverage is formed thanks to the superposition of the two lattices. The horns are fed by a modular low-loss and very compact beam forming network without any orthogonal law constraints that would reduce the antenna RF performances.
In this activity, the emphasis is given to the redesign and additive manufacturing of the beam forming networks of the MFB antenna, with a primary goal the reduction of their weight.
During the first phase of the activity, three different manufacturing routes based on various AM technologies are investigated. A simple demonstrator implementing a new hybrid E-H divider is designed and manufactured to compare the three manufacturing routes and select the most promising among them for the breadboarding phase.
At the Preliminary Concept Review, the breadboard concept is selected. The breadboard is designed according to the needs of the selected AM technology, manufactured, and tested (RF, thermal, and mechanical testing). During the design work-package, some simplified parts are produced for de-risking purposes and in order to fine-tune the manufacturing route.
The project has been successfully, completed resulting in the manufacturing and testing of three representative BFN breadboard units.
