Design Of Vco And Lna Based On Cmos Process

In recent years, the research and development of wireless radio frequency transceiver system is promoted by the rapid development of the wireless communication system and the constant advancement of modern CMOS technology. And the low cost,small size,wideband and high frequency is the final goal need to be achieved in future for the design of the wireless radio frequency transceiver system,The RF amplifier and VCO are the key circuits for wideband wireless communication tranceiver. Because the inductor for CMOS process is very important to the design of cell module, such as LNA and VCO. The inductor's modeling is introduced specially. The fundamental theory and structure of the VCO and amplifier are introduced in this thesis, and their merits and demerits are analyzed. As an important part of the synthesizer, VCO directly influence the performances of synthesizer such as tuning frequency range, phase noise, power consumption and so on. After analyzing the performance parameters of VCO the thesis introduces some methods of VCO performance optimization, such as the realization of wideband tuning range, the technology of reducing tuning gain and methed of making VCO gain stable. By comparing all kinds of methods of VCO gain optimization, Firstly, the thesis proposes a wideband LC VCO. The switched capacitor array is adopted to extend tuning range and reduce tuning gain of VCO and the switched varactor array is used to make the VCO gain stable. Then, the ring voltage-controlled oscillator with low power is designed for the application to RFID system, and it uses the structure of three stages inverters with the power consumption of 1mW.As the first stage of receiver, LNA directly influences the performances of the transceiver system. The variable gain low noise amplifier can prevent instability of the receiver, and maximize the receiver dynamic range, which has widely application in wireless transceiver system. By analysing the advantages and disadvantages of the all kinds of structures of amplifiers, such as cascode topology structure, wideband match structure with filter. This thesis proposes the variable gain wideband LNA based on summarizing the technology of gain control. The purpose of gain control is achieved by controlling current of the second stage in two stages circuits; meanwhile, multiple-gated transistors (MGTR) is adopted in this circuit in order to get high linearity.