3D Manufacturing of Microwave Passive Components

Status date

The objective of this activity is to develop a complete 3D end-to-end manufacturing process for the production of lightweight, complex microwave passive components for telecom payloads. The process will be based on Selective Laser Melting (SLM), a generative rapid prototyping process. The end-to-end process and the selected material including surface finishing is validated through the design, manufacturing and test of several breadboards (EB) of passive RF components.

Passive Components are specialized in their design to the electrical, thermal and mechanical requirements of the satellite. Due to their complex internal geometry passive components often consist of several parts that have to be connected by bolts.

Manufacturing time, mass and cost can be reduced by producing these components as a single piece. This can be realised by Selective Laser Melting (SLM), a three dimensional additive manufacturing process that builds the component layer by layer. The material is defined by the electrical, mechanical and thermal requirements of the components. Aluminium with its high thermal conductivity and a thermal expansion that fits to the satellite panel is appropriate for components. These can be manufactured via SLM and must be covered by silver plating. Due to the particle size of the metallic powder the roughness of the surface will be higher than a milled surface.

The porosity of the surface and the relative complex internal geometry of some microwave components (e.g. filters) are challenging factors for the surface preparation and plating processes.

In the Frame of the project various surface treatment technologies were examined in terms of usability for the manufacturing process.


Phase I consists of two parts. The first is the technology review and initial process development. The second part is the process development and validation on simple demonstrators. During Phase II the process will be validated on complex demonstrators.


Microwave passive components show a high complexity with numerous bolts and flanges. The parts are usually milled and have to be bolted manually in a time consuming production process. Producing these parts as a single piece by a Solid Freeform Fabrication (SFF) process such as Selective Laser Melting (SLM) promises benefits in terms of time, cost and equipment weight. However disadvantages like complicated surface preparation and coating process and a higher surface roughness of the SLM parts have to be set off against the advantages to evaluate the competitive capability of the new production technology.


In the frame of the project Tesat and ILT develop an end-to-end process for production of Selective Laser Melting (SLM) microwave passive components for satellite communications. The work is divided into three parts.

The first part covers technology reviews of established Solid Free Forming processes and surface treatment technologies. A specification has been set up and an initial process is developed. The outcome of the first tasks has been used to define a list of demonstrators. Multiple sample parts were manufactured to identify process limits for the SLM technology for passive microwave components.

Based on the outcome of the first part the simple demonstrators will be designed and manufactured in the second part. The objective of producing the simple demonstrators is to evaluate the pre-selected 3D Manufacturing technology and the surface treatment concepts from first part. The demonstrators will pass verification testing to explore the quality of the design and production process. The aim of the second part is to settle the final end-to-end process.

The developed end-to-end process will be used in the third part of the project to develop and build three complex demonstrators of microwave passive components. This fabrication run shall prove the practicability of the process itself. Verification testing of the complex demonstrators according to a test plan will discover the quality of the process.


The contractual close out of the study will be in 2012.

Phase I will be finished in 2011. Phase II will follow with a duration of 10 months. Phase I deals with the general process development. The process will be applied and tested during development and production of several simple demonstrators. Once the end-to-end process is fixed it will be tested on the development, fabrication, surface preparation and finishing of three complex demonstrators.

Current status

It is possible to manufacture SLM parts for passive microwave components with sufficient mechanical, thermal and electrical properties assuming that the identified surface treatment can be applied. All electrical, mechanical and thermal characterisation carried out in the project so far indicate promising applications for RF devices. Electrical conductivity equivalent to milled processes has been reached with surface treatment.