An 8mA, 3.8dB NF, 40dB gain CMOS Front-end for GPS applications

A fully differential 0.35 μm CMOS LNA plus mixer, tailored to a double conversion architecture, for GPS applications has been realized. The LNA makes use of an inductively degenerated input stage and a resonant LC load, featuring 12% frequency tuning, accomplished by an MOS varactor. The mixer is a Gilbert cell like, in which an NMOS and a PMOS differential pair, shunted together, realize the input stage. This topology allows one to save power, for given mixer gain and linearity. The front-end measured performances are: 40 dB gain, 3.8 dB NF,-25.5 dBm IIP3, 1.3 GHz input frequency, 140 MHz output frequency, with 8 mA from a 2.8 V voltage supply