The Research On Low Noise Amplifier And Mixer For 2.4 GHz Low-Power Wireless Receivers

With the development of communication technology, the wireless communication devices are required to be smaller size, higher performance and longer battery lifetime. Then the RF circuits are required to be smaller size, highly integrated, higher performance, lower cost and lower power. Therefore, we research and design a low-power 2.4 GHz ISM (Industrial, Scientific and Medical band) band wireless receiver RF front-end.The paper briefly introduces the research status and significance of the RF front-end circuit, and illustrates that it is important to design a low power low noise amplifier (LNA) firstly. Secondly, the basic theory of LNA is summarized systematically, and a low power LNA circuit is presented. Finally, a low power RF front-end circuit is also presented. The main achievements of this work consist of following aspects:(1) The current various configurations of the low power RF front-end circuits are analyzed and summarized systematically. Also their advantages and disadvantages are compared. The existing low-power methods of the LNA and mixer are also introduced and compared.(2) A 2.4 GHz low-power CMOS low-noise amplifier is presented. The proposed LNA topology is basically a two-stage CS amplifier, so it can work at a very low supply voltage, and it can also operate at a very low current consumption by employing a current-reused architecture. Compared to the presented current-reused two-stage common source topologies, we mainly modified the input matching circuit architecture for better noise figure and gain. From the simulation results, the fully integrated LNA exhibits a gain of 14.4 dB and a noise figure of 1.68 dB at 2.4 GHz, the input matching (S11) is-18.1 dB while consumes only 960μW.(3) A 2.4 GHz low-power low-noise CMOS LNA is presented. The LNA can reduce power consumption by using current-reused technique. For the common source input matching LNA, power and noise matching cannot be obtained simultaneously at low current bias. Thus, a common-gate input structure is employed in this paper. The input LC network can help to achieve the input matching and reduce noise. Both of the analysis and simulation results show that the LNA achieves better gain and noise figure. It provides a forward gain of 15.5 dB with a noise figure of 1.68 dB. The input and output match very good while consumes only 1.05 mW.(4) A mixer structure is designed for the designed low noise amplifiers. The co-simulation results of the LNA and mixer show that the RF front-end structure can achieve quite superior performance with relatively low power consumption. It provides a gain of about 10 dB with a noise figure of 7.4 dB and IIP3 of -7.0 dBm. The input match very good while consumes only 3.0 mW.The proposed circuits are simulated in TSMC RF CMOS 0.18μm technology by ADS2008. The simulation results show that it has a similar performance compared to the recently published low power designs.