Low Noise Amplifier Design Based On GaAs HEMT

Electronic technology based on micro-electronic is the base for promote information development in 21 century. Integrate circuit is the kernel and principal part of micro-electronic technology. And it is also the base of information industry. The wireless communications IC consists of transmitter modules and receiver modules. Low Noise Amplifier (LNA) is the key in receiver modules. As the first block of the wireless receiver following antenna, the noise performance of LNA determines the noise performance of the entire system. Therefore, to improve the sensitivity of the receiver, the research of LNA is of great importance.This paper gives an introduction of noise theory first. Then it presents the fundamental principle of the microwave circuit design, including the description of two-port network, transmission line and impedance matching. The circuit forms which are in common used are analyzed and balanced circuit is chosen in this design after reading a great deal of pertinent literatures. The formulations of low-noise and high gain matching design are achieved according to the noise of two-port network and broadband matching theories.In this paper, the low noise, high electron mobility transistor FHX14LG of Fujitsu Company is used. Combining the broadband amplifier, low noise amplifier and design technology, the input and output parts of the circuit are designed. The amplifier works in the low noise and high gain area. The design and simulation results of 3dB coupler are obtained by the simulation software ADS(Advanced Design System ADS 2005A). The gain and noise are of great improvement. Then the DC bias circuit is given. The layout is simulated with Momentum simulator in ADS and the results are accord with the demand of the design. At last, the layout of the circuit is realized by Protel.