Design of a radar in order to detect debris in the GEO

In this thesis, we design the base of a 5 GHz radar mounted on a satellite in order to detect debris in the geostationary orbit. The radar cross section of a cube the size of the wavelength is computed, its dependency on the frequency and angle of incidence are discussed. In order to scan the whole GEO, the radar flies on an orbit 150 km under the GEO, and has a steerable beam thanks to beamforming using an array of antennas. A constant value is found in order to approximate the RCS of a plate with a size close to the wavelength, as well as an analytical approximation of the RCS at lower frequencies and a curve fitting for higher frequencies. A design of a patch antenna array with a squared cosine distribution for the width of the patch is proposed, with a maximum gain of 30.3 dBi. An analysis of the SNR of the radar shows that the cube is visible on average up to 90km, and the radar is capable of detecting until the end of the GEO at a distance of 350 km objects with a RCS equivalent or greater than a sphere with a radius of 1m.