A dual-mode RF receiver with low-IF architecture has been developed for L1-band Global Positioning System (GPS) and Galileo system in a 0.18- mum CMOS process. The channel-selecting bandpass filter centered at 4.092 MHz has programmable bandwidth (2.046 MHz, 4.092 MHz), which allows the reception of GPS and Galileo signals. A fractional-N phase-locked loop generates the local oscillator signals, which allows multiple reference clock frequencies, and in turn, share of a reference oscillator with other systems. The noise figure of the receiver is 4.5 dB, while consuming 41.4 mW from a 1.8-V supply. The image signal is rejected by more than 34 dB.