Key Modules Of L-band Satellite Navigation Receiver

With rapid development of aviation, aerospace, communications and computer technology, the satellite navigation systems are widely used and greatly expanded. The high demanding performance requirements for satellite navigation such as high positioning accuracy and some other special functions have become hot researches. In this paper, the low-noise amplifier and mixer which are two key modules in RF front-end of L1-band GPS are analyzed and discussed. The improving methods of low-noise amplifier and mixer are studied and used in traditional low noise amplifier and mixer which improve the performance of the low noise amplifier and mixer.In this paper, the improvements of low-noise amplifier is stuied, which optimize the performance of noise and gain simultaneously. The design of advanced low noise amplifier is given in this paper. With the improved low-noise amplifier used, the minimum noise and maximum power transmission are obtained simultaneously.In this paper, the performance of the traditional double balanced Gilbert mixer is studied, and some improvements are given. The noise, conversion gain and linearity of the mixer are improved by using bypass current injection circuit. The use of pseudo-differential structure improves the integration of the circuit.The improved low noise amplifier is implemented in TSMC 0.18 μm CMOS technology. The simulation results show that the noise of the improved low-noise amplifier is 1.063 d B. The gain of low noise amplifier is 15.92 d B.The S11 and S22 of low noise amplifier are less than-15 d B, and the value of P1 d B is-15.7d Bm. The power consumption is 5.31 m W.The improved double balanced Gilbert mixer is designed in TSMC 0.18 μm CMOS technology.The simulation results show that the noise of the modified double balanced Gilbert mixer is 15.31 d B at 4 MHz with the conversion gain of 13.15 d B, the P1 d B compression point of-15.4d Bm, and the power consumption of 6.48 m W.The noise performance need to been improved in the low-noise amplifier. Reducing noise of low-noise amplifier is the key factor to improve the noise performance of receiver system. Using noise canceling technology can reduce the noise of low noiseamplifier. In order to improve the compatibility of multi system satellite navigation, the design of multimode RF front-end structure is the key step. The design of the low noise amplifier with multiple frequency compatibility is the key point of multimode RF front-end, so the multiple frequency low noise amplifier is the direction of future research.