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

With the development of multi-standard communication technology, the circuitsand systems of wireless communications are moving in the direction of the multi-bandand wideband development. Corresponding requirements have been made about radiocircuit, namely, low-cost, miniaturization, high integration, high performance and lowpower consumption so that the wireless communication device will enjoy a smallersize, better performance and longer battery operation life. A LNA (low noise amplifier)and a mixer form the RF front-end circuit which is the key link of a wireless receiveras well as the major energy components of the receiver. Therefore, reducing the powerconsumption of the RF front-end is of great significance to reduce the overall powerconsumption of wireless receivers. Based on these theories, this paper hasaccomplished its research and design of low-power amplifier and mixer of the0.8~2.5GHz wireless receiver with low consumption.This paper briefly introduces the research background and significance of thebroadband wireless receiver, analyzes the current research status of low-powerbroadband low noise amplifier and mixer both home and abroad, meanwhile, theadvantages and disadvantages of a variety of circuit structure are summarized andcompared. And then on the basis of the literature review and theoretical analysis, anew type of low-power broadband low noise amplifier and mixer circuit withlow-voltage is presented. The main work and achievements are as follows:(1) Proposed a wideband CMOS LNA of low voltage and low-power, which canstill work within the frequency range of0.8~2.5GHz. This circuit uses a common gateinput to achieve wideband impedance matching and uses the technology of noisecancellation to improve the noise performance of the LNA. Simulation results showthat in the0.8V power supply voltage, input reflection coefficient of a low-noiseamplifier is less than-18.5dB, output reflection coefficient is less than-18dB,forward gain ranges between17.4~17.9dB, it also enjoys favorable gain flatness withnoise figure of2.62~3.07dB and power consumption of8.7mW.(2) Proposed a wideband mixer circuit of low voltage and low-power, which canwork within the frequency range of0.8~2.5GHz. Based on the Gilbertdouble-balanced mixer, the wideband mixer circuits can reduce the operating voltageand the circuit power consumption, and improve the conversion gain by using the folded structure and the current-reuse technique. Simulation results show that with theoperating voltage of0.8V, the double sideband noise figure of the mixer is6.97~7.33dB; the conversion gain is12.9~13.7dB; the input third order intercept pointis about1.8dBm and the power consumption is only3.2mW.The circuit proposed in this paper applies a0.18μm RF CMOS, it is simulatedand designed by ADS software.Compared with the literature at home and abroad inrecent years, in the same condition of low-power consumption, the low-noiseamplifier proposed in this paper has some certain advantages in terms of the operatingvoltage and the noise figure etc. And the proposed mixer enjoys excellentperformances in such aspects as power consumption, operating voltage, conversiongain and noise, and so on.