In this paper, an alternative approach for radio-frequency (RF) design is presented. The approach is focused on reducing the design cost and time to market mainly adopting a design flow which allows to easily estimate the system performances and the use of commercial off-the-shelf (COTS) parts. At the same time, it mitigates the risks typically associated with the use of such components. It is based on a programmable, flexible and low-cost electrical ground support equipment (EGSE) associated with the use of a suitable simulation technique. In particular, a methodology for RF system design is discussed and how the EGSE may be used as alternative way to perform functional test and obtain rapidly the results. The EGSE, associated with the simulation model, may also be used to predict the behavior of COTS components over different operation conditions, such as the harsh environment of space. An example of an intermediate frequency (IF) filter designed for a telemetry and telecommand (TMTC) system is presented. The proposed methodology has been successfully applied to the filter design.