Saving Space on Satellites: Comparing a Q-Band TWTA Amplifier Assembly to a Highly Integrated SSPA Solution

This paper compares two different Q-Band (37 GHz to 42 GHz) satellite downlink assemblies: One with traveling wave tube amplifiers (TWTAs) and one with semiconductor power amplifiers (SSPA, solid state power amplifier). While the former is established and widely used on geostationary telecommunication satellites, it is comparatively large and heavy. The SSPA-solution has comparable electrical performance for a fraction of the space used on the satellite. The SSPA has a slightly lower output power than the TWTA and is less efficient, but performs very similarly with regards to linearity, while using less than half of the space previously occupied by the TWTA-assembly, cutting the weight by over 40 % as well.