Mesh antenna design is a smart satellite solution

A new mesh antenna design for satellites enables contouring of the surface shape for spot beam enhancement.

A prototype 2.6 m-diameter metal-mesh antenna reflector developed by a European consortium can be manufactured to reproduce any surface pattern that antenna designers wish — something that was previously possible only with traditional solid antennas.

Satellite antenna reflectors often have a surprisingly ‘bumpy’ appearance, with their basic paraboloid convex shape distorted with additional peaks and valleys. Those bumps serve to contour the radio frequency beam, typically to boost signal gain over target countries and minimise it beyond their borders.

“This is really a first for Europe,” said European Space Agency (ESA) antenna engineer Jean-Christophe Angevain. “China and the US have also been working hard on similar-shaped mesh reflector technology.”

The lightweight mesh solution “is needed so that sufficiently large antennas can be deployed in orbit, which would otherwise be too bulky to fit inside a launcher fairing, while also meeting required performance levels”, he added.

The ESA’s ‘Advanced techniques for mesh reflector with improved radiation pattern performance’ (AMPER) project has been developed with Large Space Structures in Germany as prime contractor and TICRA in Denmark as subcontractor.

According to Angevain, tailored surface shaping is traditionally achieved using traditional metal or carbon fibre reinforced plastic composite reflectors.

“The challenge was how to reproduce such shaping using a mesh reflector design,” he said.

“The obvious solution would have been a conventional tension truss double-layer solution, with the mesh held together tautly on an alternating ‘push and pull’ basis.”

Instead, he said, “A smart alternative solution has been proposed and followed by the team.”

The Hertz Chamber testing facility at ESTEC.

“The design of our shaped mesh reflector is based on tension members supported by a peripheral truss structure which enables decoupling of the shaped surface and the structure,” said Leri Datashvili, CEO and Chief Designer at Large Space Structures.

“Therefore, the design can be implemented for any size of reflector, for any frequencies ranging from P-band to Ka-band. Furthermore, either deployable or fixed reflector technology can be realised.”

“This 2.6 m ‘breadboard’ prototype proves the concept at C-band frequency, and the RF measurements have shown good correlation with radio frequency and mechanical predictions,” added Angevain.

The AMPER project was supported through ESA’s Technology Development Element, with prototype testing carried out in ESA’s Hertz chamber at its ESTEC technical centre in the Netherlands.

The AMPER team plans to next produce a deployable version, intended for use by Earth observation and telecommunication satellites.

Top image: The AMPER antenna under test at ESTEC. Images courtesy ESA.