KuDGR Dual-Gridded Carbon Fibre Reinforced Plastic Reflector

Objectives

The KuDGR is a full CFRP dual gridded reflector with shaped reflecting surfaces. The dimensions of the RF surfaces are 1200 mm x 960 mm. Each of them is made out of individual single rods (patent: 10711326.8-1959/2406855) bonded together to a ring. A thermal stable CFRP structure called omega ring gives the two grids the mechanical stability. After developing the manufacturing process of the single rods aiming for a good RF performance a sample test campaign with grid elements was performed. In the preliminary design phase the RF and mechanical/thermal performance was elaborated. After that the planned assembly procedure was verified on a breadboard. With this experience the detailed design phases could be focused on interfaces and RF performance optimization including analysis on scattering effects. Finally an engineering model of the KuDGR was manufactured and tested and measured in a thermal vacuum chamber. In a second test phase the RF performance was measured in a compact range.

Challenges

The main challenge was to establish a process for manufacturing about 500 individual shaped rods and assemble them to two gridded surfaces. Also the geometrical measurement of the assembled grid was difficult, as there is no continuous surface, but single rods with a diameter of 1 mm.

Benefits

Due to the design there is a significant mass reduction. Moreover the acoustic loads are reduced.

Features

Most lightweight linear polarized RF surfaces could be established. In connection with a full CFRP omega ring a lightweight DGR was developed.
Dimensions: 1200 mm x 960 mm x 250 mm
Mass: 4.2 kg (goal <6 kg)
TX 10.95 - 12.5 GHz
RX 13.75 - 14.5 GHz

System Architecture

The KuDGR is based on single rods bonded together to a grid. This is the RF surface. This grid is bonded to a 3D shaped L ring. This assembly is bonded in a symmetrical omega shaped elliptic ring. For top deck applications the ring is mounted by three isostatic mounts to the panel.

Plan

1. Antenna & KuDGR Requirements Consolidation
- RF requirements - Thermo-mechanical requirements
2. KuDGR Concepts, Technology & Design Trades, Baseline Selection
- Concepts for RF design and RF analysis - Concepts trade-off and baseline selection - CFRP rods development plan, shaping feasibility, sample production
3. Antenna & KuDGR Preliminary Design & Analysis
- KuDGR preliminary RF, thermal, mechanical design - B/B manufacturing and sample testing - TED measurement method assessment& investigation - KuDGR EM testplan and MGSE identification 4. Antenna & KuDGR Detailed Design & Analysis, Test Predictions - KuDGR detailed design & analysis
- KuDGR test predictions - CFRP rods & grids manufacturing process definition - Test plan - Test procedures 5. Manufacturing and Testing - Manufacturing of KuDGR and MGSE
- TVC test including TED measurement - Additional shape measurement and feed alignment - RF test 6. Review of antenna performance.

Current status

Project finished

Contacts

ESA Contacts

Status date

Thursday, February 25, 2016 - 09:23