Abstract: This paper describes a CMOS low noise amplifier (LNA) plus the quadrature mixers intended for use in the front-end of portable global positioning system (GPS) receivers.The LNA makes use of an inductively degenerated input stage and power-constrained simultaneous noise and input matching techniques.The quadrature mixers are based on a Gilbert cell type.The circuits are implemented in a TSMC 0.18μm RF CMOS process.Measurement results show that a voltage conversion gain of 35dB is achieved with a cascade noise figure of 2.4dB,an input 1dB compression point of -22dBm,and an input return loss of -22.3dB.The fully differential circuits only draw 5.4mW from a 1.8V supply.

Key words: CMOS RF IC, GPS, low-noise amplifiers, mixers, receivers, noise figure