Self-testing solution are very useful not only for make sure that devices are operating in the correct way, but also to realize system auto-calibration: auto-calibration is based on the experimentally extraction of proper parameters and it is usually realized by adopting radio frequency noise injection subsystems. In these cases, the systems use power acquisition devices, based on diode detectors, to perform the measurements; this solution denotes poor reconfigurability, unless a very complicated system architecture is adopted. In this paper we prove that the measurements needed for the over mentioned purpose, can be performed avoiding the application of complex architectures, by using software-defined radios with high level of potential reconfigurability and flexibility.

This paper proposes a Ka-band receiver front-end for future CubeSats Low-Earth Orbit (LEO) to Geostationary (GEO) inter-satellite links. The receiver is able to support very high data rates (up to 100 Mbit/s) in Quadrature Phase-Shift Keying (QPSK) when in the line of sight of a GEO satellite that is equipped with a steerable 70-cm antenna and transmitting a 25-W signal. The originality of the proposed approach is twofold. First we will demonstrate the receiver feasibility based on a class of miniaturized and low-cost microwave integrated circuits, currently available on the market. In particular, our receiver is based on a novel combination of integrated Low-Noise Amplifiers (LNA) with an image rejection filter, the latter exploiting the Substrate Integrated Waveguide (SIW) technology. An optimization of the via placement proved to be able to reduce the need for shielding apparatuses, thus simplifying the mechanics and reducing mass, volume and hardware costs. Secondly, we will propose a noise injection circuit capable of measuring and calibrating the receiver gain, also during in-orbit operation. Self testing capabilities are particularly relevant for CubeSats because the usage of commercial components poses serious reliability issues.