Research And Design Of Mixer For GPS Receiver Under180nm Process

With the development and improvement of Global NavigationSatellite System (GNSS), GNSS has more and more applications. How tomake navigation satellite systems get higher performances and morefunctions become a current research focus, so the study of the radiofrequency receiver which used in navigation satellite system has beenwidely concerned. Multi-band, multi-mode, low power consumption, lownoise, high linearity receiver is the current trend.Dual-mode GPS receiver consists of a low noise amplifier,down-conversion mixer, frequency synthesizer, programmable gainamplifier, complex filter, automatic gain control circuit and so on.The mixer is an important block in signal path, and its main functionis to convert the radio frequency input signal to baseband output signal. Itsperformance will be a great impact on the total system performance, suchas conversion gain, noise, linearity.The radio frequency receiver has two operating modes, high gainmode and high linearity mode. In this thesis, an active mixer has beendesigned to use in the high gain mode path, and a passive mixer has beendesigned to use in the high linearity mode path.In this thesis, firstly, an introduction about the background ofnavigation satellite system and radio frequency receiver is presented,including a brief introduction of GPS, GLONASS, GALILEO and BeiDouNavigation satellite system, secondly, we introduce the RF receiverarchitectures and RF specifications. Thirdly a detail introduction about thebasic principles of mixer and the design of the down-conversion mixer is presented, the active mixer is complemented by using the gilbert structure,the negative feedback resistor and current bleeding technique is adopted toimprove the noise and linearity performance; the passive mixer iscomplemented by using current-driven double balance architecture. Thenwe introduce the bias circuit, including the principle of constant-gmcurrent source and bandgap reference current source. Finally, thesimulation results under TSMC0.18mprocess are listed.