# Characterization of a COTS-Based RF Receiver for Cubesat Applications +
## 1 Introduction  
Recently, the research on the framework of the aerospace applications has been devoted to CubeSats because they are small and compact, characterized by low launch costs, and suitable to create satellite constellations that can improve the terrestrial network infrastructure, providing better global coverage. The CubeSats are typically designed using Commercial Off-The-Shelf (COTS) components. The use of COTS components has the great advantage of widely reducing the costs of the satellite subsystems, since additional screening and reliability tests/inspections are not mandatory. Therefore, in recent years, they have generated a great deal of interest from the industry of small satellites, especially for Low-Earth Orbits (LEOs) [1, 2]. The LEOs are the best environment for the allocation of hardware based on COTS components. The satellites find a less severe environment in such orbits, within which the components, even if not space-qualified, could \"survive\" the strong temperature ranges and the ionizing radiations. The use of COTS components for space missions is well documented in the literature. The COTS components are used to make both the power electronic [3, 4, 5, 6] and digital [7, 8, 9] boards. The term\"COTS\" is also related to the test facilities [10; 11] and electrical ground support equipment [1; 12]. Finally, the COTS-based design has been even adopted for RF systems [13; 14; 15; 16; 17; 18; 19; 20]. They include navigation systems [13; 14], transmission data systems for deep-space and remote-sensing applications [15; 16], and modules for communication with the earth [2; 17; 18; 20]. The main problem in the use of COTS components in space applications is the increased risk of failure of the satellite subsystems that implement them. Their suitability for use in space must always be verified by looking for reliability information in the literature, mostly related to radiation tolerance. Some selection criteria of COTS components, even standardized, have been developed in recent years to help designers to make a reasonable choice of component considering the orbit where the satellite will be placed. The main issue of an approach based on selection criteria is related to the limited available information associated with the radiation tolerance of the COTS components. Since radiation is the main cause of failure in the space, the components are often tested for their tolerance to radiation under appropriate conditions, and the corresponding test reports are filed in databases which are not always freely available. Moreover, most of the components for which a radiation test report is available are components for low-frequency and power applications. Few Radio-Frequency (RF) components are available in such databases. For this reason, the design of COTS-based RF front-ends that have high-performance and reliability at the same time is particularly difficult. In the literature, there are few papers that report RF front-ends implemented with COTS integrated circuits [21; 22; 23], for which reliability information and radiation test reports are more easily available. However, such an approach solves the reliability issue, but does not always allow the creation of applications with very high performance, since the integrated circuits are designed to be general-purpose for terrestrial applications. The intent of this work is to find an efficient solution to deal with this issue, considering as a case study the design of an RF receiver operating at a 2025-2110 MHz frequency range, conceived for CubeSat applications. The starting idea was to design a completely custom device with a high performance and high reliability using only COTS components, even without having information regarding their behavior under radiation. Such design requirement has been addressed from a purely analytical point of view in our original work, presented at the Metrology for Aerospace 2019 conference [17].