A practical RF front-end for high performance GNSS receivers

We present the design and implementation of a GNSS front-end intended for receiving the L1/E1 band of GPS/Galileo and GLONASS signals. The proposed scheme consists of a radio frequency (RF) stage, with a low noise amplifier which has a noise figure of 1.1dB. Then, the RF signals are down-converted to an intermediate frequency, where the GPS/Galileo and GLONASS bands are separated. Thanks to this separation, a considerable reduction of the necessary sampling rate for the digitalization stage is achieved. This simplifies and reduces the power consumption of this stage of the complete GNSS receiver. The present design is versatile since it can be used to receive signals from the L2 band by replacing only a few components, without the necessity of modifying the printed circuit board. Measurements realized to an implemented prototype that validate the proposed design are presented.