Low Cost Precision Manufacturing RF Passive Hardware

Status

Ongoing
Status date

2019-09-05
Activity Code

5C.278

Objectives

The project aims at combining the capabilities of additive manufacturing with electroforming to offer a viable alternative in the manufacturing of RF passive components such as Ka band filters. These particular filter components have among the highest mechanical tolerance and surface roughness requirements. Furthermore, these components show quantifiable RF response to environmental changes (temperature, vibrations, stress…), as well as high power RF (PIM), which can be used as a precise tool to evaluate the stability of an employed manufacturing technology with respect to space relevant environmental conditions. The aim of this study is to demonstrate the successful performance and resistance to space relevant environmental conditions of components featuring:

Lower costs (at least 25% cheaper)
Lower lead time (at least 25% shorter)
Increased flexibility in manufacture-able RF designs
Mass savings

Challenges

The main challenges of the project are the successful fabrication of the selected components via 2 manufacturing routes:

1) Based on Stereolithography:

Additive manufacturing of a mandrel
Mandrel post processing
Mandrel conductivizing
Electroforming
Mandrel removal
Interfaces machining

2) Based on Selective Laser Melting:

Additive manufacturing of the skeleton in Aluminium
Surface preparation by chemical means to ensure good adhesion of metal plating
Electroless plating of the component with a sufficient thickness (depending on the skin depth) in order to become RF functional.

Each of the aforementioned steps involves technological challenges that need to be very carefully controlled.

Benefits

The benefits from additive manufactured RF hardware are numerous: increased design flexibility, significant mass reduction, potential cost reduction for low to medium volume production, reduced lead time (typically 4-6 weeks), possibility to replace complicated assemblies of multiple parts with a single monolithic component (or an assembly with much less parts), improved RF performance due to the possibility to implement advanced designs that are impossible to manufacture with conventional subtractive fabrication methods.

Features

The most important feature of the components fabricated is the RF design flexibility, combining several functions like a bend, a 90° twist and 8 poles filters into one single piece. By adding RF functions to your component, it reduces the cost of the hardware by 30% compared to conventional products while the lead time is typically between 4-6 weeks. A significant mass reduction could be achieved also in that case 2 times compared to the respective conventional hardware.

In terms of RF performance, AM components are meeting realistic specifications established on the basis of existing commercial requirement.

System Architecture

The main filter products targeted by this project are the following:

High Power Ka band ODMUX operating at 20 GHz and needed in high volumes
Ka band CMUX (low power, dual mode) operating at 30 GHz and needed in high volumes

More largely, different components developed could be a part of a feed-chain, i.e. components with different functionalities (e.g. diplexers, polarizers, OMTs etc.) sitting behind the feed horn of a reflector-based antenna system.

Plan

As soon as the detailed review of the different AM technologies that are suitable for the activity has been performed, several manufacturing routes have been evaluated as proof of concept. The first milestone was the selection of the most promising techniques. The second milestone is achieved with the complete RF and mechanical design of the hardware to be fabricated with end to end manufacturing processes. Out of the manufacturing routes, the hardware was fully tested in space environment which completed the third milestone.

The last milestone was the assessment of the limitations of the proposed technologies and to draw an associated roadmap to develop flight models.

Current status

Project has been completed/developed from Feasibility Study to Demo.