Biography
Enrollment Date: 2011
Graduation Date：2014
Degree：M.S.
Defense Date：2014.05.27
Advisors：Baoyong Chi
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Research on Key Techniques of Analog Baseband in Mm-Wave Front-End Chips
Abstract:
With the increasing demand for mass quantity data and long distance all-weather wireless communication, wireless communication in the traditional bands has become more and more unable to meet people's needs, millimeter wave wireless communication has become a new research focus of industry and academic circles. The main aspects of millimeter wave band applications from low frequency to high frequency in turn are: millimeter wave communications, millimeter wave imaging and millimeter-wave radar.
One respect of the thesis is a wideband IF programmable gain amplifier(PGA) used in 60GHz millimeter-wave communications receiver which is applied to millimeter wave communication, and the PGA is based on CMOS technology. A novel design technology of wideband PGA circuit is proposed, compared to other technologies of the PGA at the present stage, The proposed technology can make the gain of PGA programmable and without introducing additional parasitic at the same time, and use the parasitic capacitance of switch transistor to increase the bandwidth and gain adjustment range of the PGA, make the power consumption of the PGA only about one-tenth of the PGA with similar indicators at the present stage. The paper also prove that the circuit technology can applies to the vast majority of broadband PGA generally In terms of both theory and practical circuit, and simplify the design of wideband PGA process greatly, reduce the designing difficulty of the wideband PGA at the same time. The first version of PGA has been integrated into one whole 60GHz wireless transceiver and implemented in TSMC 65nm CMOS process successfully, The test results show the PGA is working properly, and all aspects of performance that meets the design specifications. The measurements on the receiver front-end show that the proposed PGA achieves 18 dB variable gain range with bandwidth much wider than 3GHz. The PGA consumes 10.7mW power from a 1.2-V supply voltage with a core area of only 0.025 . The power and layout Area of the revised have optimized individually to 10.7mW and 0.0024 .
The other respect of the thesis is the analog baseband and analog-to-digital converter(ADC) used in 77GHz Millimeter - wave phased array ranging radar, which is applied to millimeter-wave radar, and the analog baseband and ADC are based on CMOS technology too. Analog baseband constituted by cascaded three - level PGA, low - pass filter and DC offset canceler ( dcoc ) .PGA with the resistance feedback structure, the advantages of the structure are: the gain control is accurate, gain fluctuation in the corner is small and the linearity is high. Filter in a compromise with flatness, with inhibitory rate, linearity and power, eventually five - order butterworth structure is choosed, and use resistor arrays to compensate the bandwidth fluctuationin the corner. DC offset of analog baseband is significant improved by DCOC loop, use the miller effect of capacitance in the loop so that the value of capacitance can be reduced significantly, so the area of layout also can be greatly reduced. Moum capacitance is used in the DCOC loop, further reduce the layout area . The proposed ADC uses successive approximation Register(SAR) 8 bit structure to realize analog- to-digital conversion.The foregoing circuit has implemented in TSMC 65nm CMOS process successfully, the post-simulation results show that the entire analog baseband has the advantages of low noise low power, high linearity, accuracy gain and bandwidth control and wide dynamic range of gain and bandwidth, and the proposed ADC has the advantages of low power consumption and small layout and high ENOB.