This chapter starts with self-localization via Global Navigation Satellite Systems (GNSS). The GPS and Galileo systems are presented. With regard to the necessary RF front-end development, the antenna technology and LNA development are discussed. The FMCW radar technology used in vehicles, among other things, is discussed in great detail. Both the hardware structure and the theory of this distance measurement method are presented and derived in more detail. In addition to the classically known methods with continuous frequency sweep, discrete frequency variation is also discussed. The latter can be performed over a wider bandwidth with integrated VCOs. Finally, the complex measuring SFCW radar system, which is also increasingly being used, is presented and classified.