Phase coding for satellite radar cross section reduction – CHORUS

The CHORUS project is part of the very general context of the control of ElectroMagnetic (EM) waves using artificial surfaces called MetaSurfaces (MS). The latter are thin and made up of arrays of elements interacting with the EM wave and distributed with a periodicity less than one wavelength. MS achieve a specific boundary condition to modulate the behavior of EM waves. They can be passive and in this case perform a predefined and fixed function. The integration of active elements such as switches makes it possible to design reconfigurable MS allowing dynamic adaptation to the needs of the system. They thus find numerous applications in the fields of RADAR or communicating systems thanks to their filtering, focusing, redirecting or absorbing capabilities of EM waves. MS have been the subject of a great amount of research and development for the past twenty years. Some applications are reaching maturity (reflect or transmit arrays, frequency-selective surfaces) but research works as the degrees of freedom defining the MS are numerous (geometry of the elements, materials used, overall static or dynamic synthesis of the surfaces, temporal modulation of active MS) and significant technological challenges remain (integration of a very large number of active elements and control of these elements in particular).

In this general context, CHORUS targets the proposal and exploration of new MS concepts making it possible to reduce the RADAR signature (RADAR Cross Section, RCS) of the objects or carriers on which they are placed. More precisely, the carriers considered will be satellites and the project is therefore part of the space theme of the call for projects: “In the field of satellites, reducing their RCS by MS coatings could contribute to increase the resilience of these systems”.

In this objective of reducing the RCS of satellites using MS, the targeted innovations will concern:
- the use of absorbing composite materials in the design of MS with binary phase coding,
- the exploitation of the techniques of spatial and time modulation of MS with binary phase coding,
- the combination of the two previous approaches: absorbing materials and spatiotemporal modulation of MS with binary phase coding.

The CHORUS consortium involves three French academic laboratories (IEMN, IETR and Lab-STICC) recognized nationally and internationally in the fields of MS and new materials for microwave antennas and circuits.