Author: Teemu Ruokokoski
Date: June 12, 2019
The European Space Agency (ESA) is aiming for small landers in future planetary exploration missions. This imposes drastic design constraints on individual components in terms of size, mass and power. A reliable measurement of the ground distance by an altimeter is the key asset for the planetary descent and landing system. In the case of small landers, the size, mass and power consumption of the altimeter must be minimized as well. Harp Technologies Ltd. was responsible for developing a radar front-end of a planetary altimeter. The main project objective was to analyse the most promising radar concept for ESA’s exploration programme, and then design and bread-board the chosen concept. A development of a frequency modulated continuous wave (FMCW) radar front-end for the frequency band 13.25 – 13.35 GHz is described in this Licentiate thesis. At first, a theoretical background for pulse and FMCW radars is presented. Based on the operational requirements, the FMCW radar concept is selected for the further development. The detailed design of the radar front-end is then described, and the performance of the manufactured breadboard is verified in laboratory conditions. The measured power consumption of the radar front-end is less than 2.5 W. The output frequency range is 13.28 – 13.389 GHz and the output power is approximately 14 dBm. The noise figure of the receiver is 6.5 dB. The performance of the realised radar altimeter is deemed satisfactory, and it has also sufficient improvement potential to be suitable for the next phase of the project (i.e. Engineering Model).