The Design Of Low Voltage And High Conversion Gain Mixer

In recent years, wireless communication technology developed very rapidly, and became used in communications widely, such as computers, medical equipment in all areas of society, people enjoy the convenience of the growing information technology. Microelectronic industry-based RFIC technologies has a rapid application in many areas of society for its low cost, high integration, and good performance, such as digital mobile communications, wireless local area network, global positioning systems, radio frequency identification systems, etc., and effectively promote the development of wireless communication technology.Therefore researching and developing of RFIC technology has important significance. Wireless communications receiver is an important part of the equipment which is received signal module. Its function is to amplify the received signal, frequency conversion, demodulation processing, and finally to the base-band circuit for data analysis. Different structures of the receiver affect on the machine's performance differently, This article describes the superheterodyne receiver, low-IF and zero IF receiver, analyzes and compares the advantages and disadvantages of the three, providing the right structure for the receiver circuit design.Mixer in the RF transceiver is a very important component, It is the high frequency signal down-conversion, or vice versa, to complete the conversion of the signal frequency. Mixer with different structures will produce different performance. This paper analyzes several common mixer, and compare the advantages and disadvantages. At the same time, the mixer is a nonlinear device, its performance will affect the entire receiver system. This article describes the main indicators for the mixer, and discusses the mechanism producing various kinds of interference signals.This article describes the design of the current mainstream technology mixer, in order to design high-performance mixers, at low voltage and low power consumption, introduced LC-tank structure mixer, using the current complex structure of the mixer, and with folded cascode mixer. In order to improve linearity, introduced feed-forward techniques mixer and sampling mixer. At the same time, the paper introduced the current widely used Gilbert mixer and recent research.On the basis of reading large amounts of data and learning the theory of knowledge, this paper improves the traditional Gilbert mixer by replacing the original with the active load resistance to reduce the supply voltage of the circuit and increase the circuit's output swing. Besides, the paper improves the gain of the mixer by using folding trans-conductance stage with current reuse mixer instead of the traditional structure to reduce the supply voltage requirements and designs a suitable mixer circuit for wireless LAN standards, finally passes the simulation.In this thesis, the mixer using TSMC 0.18um CMOS process, the frequency of the input RF signal is 2.4GHz, the LO signal frequency is 2.3GHz, IF frequency is 100MHz. Simulation results show that:1 d B compression point is -3dBm, input third order intercept point is 8.5dBm, conversion gain is 12.7 dB, the power supply voltage is 1.8V, power consumption is 10.8mW, noise figure is 8.78d B.