CMOS Millimeter Wave Power Amplifier Research And Design

Recently, with the rapid and wide bandwidth development of wireless communication technology, high transmission rate of millimeter-wave circuits become the development trend of mobile communication systems.Standard CMOS technology feature size continues to reduce, the unit current gain frequency and the unit power gain frequency of MOSFET have reached hundred of GHz or even hundreds of GHz, So millimeter-wave RF front end circuits based on standard CMOS process are possible. Accurate model, low quality factor and high loss of passive are the bottleneck of CMOS millimeter-wave power amplifier. Other difficulties are low transconductance and breakdown voltage of MOSFET. For the bottlenecks and difficulties of millimeter-wave CMOS power amplifier design, the author give a detailed study of CMOS silicon-based transmission line and design a millimeter-wave band-pass filter based on SMIC 0.18um RF-CMOS. Followed, a 24GHz broadband power amplifier based on IBM 90nm RF-CMOS is designed after a detailed study of CMOS power amplifier.The main work of this paper includes:(1) Systematically introduce the basic performance silicon-based transmission lines, comparative study of several different structures of silicon-based transmission line, comparative analysis of silicon-based transmission line model, a brief discussion of several silicon-based millimeter-wave transmission lines and discontinuities. Focus on research vertical ground plane coplanar waveguide (VGP CPW) and coplanar waveguide (CPW) based on SMIC 0.18um RF-CMOS technology. The two transmission lines with different structures are studied theoretically, their loss properties characteristic impedance and isolation are analyzed; and a VGP CPW length scalable transmission line model is established. This filter is designed using low-loss VGP CPW transmission line structure with Z0 = 50Ω, as well as VGP CPW length scalable transmission line model. The on-wafer measurement results that the S-parameter of the filter fit the simulated results well. This work provides a reasonable way for millimeter wave filter design.(2) To the basic performance indicators, classes of power amplifier, input and output matching structure and Cripps theory, this paper focuses on the challenges will face in design millimeter wave RF power amplifier. Finally, design a fully integrated 24GHz power amplifier by using the IBM 90nm RF-CMOS process, the chip size is 1.2mm*0.67mm. The circuit consists of two self-biased cascode structure, self-biased cascode structure not only improves the gain, increase reverse isolation, and can effectively alleviate the gate oxide breakdown and hot carrier effects caused by reliability problems. Class A power amplifier and 2.2V supply voltage, the power amplifier simulation are: the power gain is 17dB, the S11 is less than -12dB, 22GHz-26GHz of 1dB compression point output power is greater than 15dBm, the maximum power added efficiency 14%.In summary, this paper gives a sufficient research on silicon-based transmission line widely used in millimeter-wave circuit. A 30GHz band-pass filter of transmission line is designed successfully, what's more, design a 24GHz broadband power amplifier based on IBM 90 nm RF-CMOS process. All the work as paper concerned laid a good foundation for designing the CMOS millimeter wave power amplifier.