Quadrature sampling mixer topology for SAW-Less GPS receivers in 0.18µm CMOS

This paper describes a new switching topology of a sampling mixer for SAW-less GPS (L1 band) receivers. The GPS receiver with the new mixer achieved NF 2.5dB and good blocking performance. In an alternative implementation, the mixer is stacked under a Quadrature VCO to reuse supply current. As a result, the current consumption of the GPS receiver is 11mA from 1.8V supply while maintaining blocking performance and NF of 3.5dB. Test chips are fabricated in 0.18μm CMOS process.