Many researchers and R&D laboratories in the world deal with the design of the software-based or experimental GNSS receivers using digital signal processing for work and experiments with received navigational signals. These concepts have one in common: the necessity of use of some analogue RF part before conversion of the signal to the digital domain. The problem of the RF front end design of the experimental or special purpose navigation receivers has to be solved. It is not an easy task as can be seen from many papers and conference contributions. The aim of this paper is analysis of the possibility of such GNSS RF front end design. We will discuss the following three main approaches