Design Of Ultra Wide Band Low Noise Amplifier Based On CMOS Technology

With the rapid development of wireless communication technology and CMOS process in recent years, RFIC can be achieved by CMOS process.One of new wireless communication techniques is UWB, which people from wirless communication academe attach great importance to,because of its high data speed and low power consumption. So UWB can be considered as a new huge development potential technology. Low noise amplifier is the first stage in the wireless transceiver, its high performance can ensure front-end of RF working successfully.So the research of ultra-wideband CMOS LNA is great importance for theory and practice.Firstly,this paper discussed something about ultra-wide band LNA study actuality and characteristic of CMOS RFIC.Secondly, we analyzed several familiar input impedance match circuits,and compared their advantages and disadvantages. After that,butterworth filter was designed as input match circuits.The cascode structure has many advantages,such as good gain, small Miller effect, simple structure etc.So the paper chose it as primary magnifying structure of circuits. Thirdly,we educed the optimal size of input transistor by noise improved theory under power limit. A stage matching scheme was used for heightening gain and reducing noise figure. Capacitance-coupling load circuit was used for fulfilling the demand of wide frequency. To optimize the performance of LNA,the paper designed voltage biased circuit and current-source circuit.The voltage of ultra-wide band LNA is 1.5V,based on TSMC 0.18μm CMOS process.And this LNA is simulated by ADS2008.The simulation results show that,it works in 3-5GHz, the noise figure is under 2.3dB.The gain is better than 12dB,and the maximum gain is above 14dB.The gain fluctuating range is less than 2.4dB.1dB compression point is about-15dBm. The input and output impedance match are better than-10dB. The power consumption is 19mW.