# Characterization of a COTS-Based RF Receiver for Cubesat Applications +
## 6 Discussion  
The results obtained by the experimental tests have highlighted both the effectiveness of the modeling methodology reported in [17] and the ability to make the board suitable for the characterization of single components. The compliance of the experimental results with the requirements is summarized in Table 1.  
Except for the DC power absorption, all high-level requirements have been satisfied. The DC power absorption requirement has not been fulfilled because the receiver was designed without considering the reception system of the signal at the intermediate frequency, which digitalizes it by an ADC. In other words, the output power requirement is set a priori without considering the ADC noise performance, although even the ADC can be characterized in terms of noise figure, like the other RF components [2]. If its noise model is included into the receiver system model, the amplification net gain of the receiver could decrease. A lower amplification gain would reduce the number of the active elements and, therefore, satisfy the DC power absorption requirement.  
Regarding the component-level tests, the adopted methodology is the most innovative aspect, especially if it is adopted for the radiation tests. When the COTS components are used, the radiation tests are foreseen in the final phases of the project, when all boards of the whole system are assembled. In this phase of the project, a fault in the system caused by the ionizing radiations would prevent the single component that has generated the failure from being found. A typical approach to discover the radiation behavior of the components is to test them using test boards (or the same evaluation boards) and to characterize the components with functional tests. The parameters obtained by functional tests after radiation help to improve the accuracy of the system model. Such an approach has a high cost because the radiation tests should be repeated for each element used to design the system.  
Instead, proving that the RF test points can be used to test a single component (as shown in the example of the filter characterization presented in this paper), even if it is already assembled on the board, shows that the test approach can be used to characterize individual components after the exposition to radiation. The great advantage of this is the fact that the board can be irradiated only once, whilst still maintaining the possibility of discovering the behavior of all components individually, which is very attractive for the reduction in costs. Therefore, by means of the RF test points, the RF components can be checked in order to perform debug operations and to find the component that has caused the fault after a radiation test. Moreover, RF components could be characterized without purchasing evaluation boards, which can be 10 times more expensive than the component itself and are not always available on the market.  
Finally, to complete the test methodology, a system of mechanical switches has been also foreseen on the board to allow to switch on and off only components under test. In addition, the tests are possible even in the presence of the shields, since they have been selected with a removable cover.