Biography
Enrollment Date: 2008
Graduation Date：2011
Degree：M.S.
Defense Date：2011.05.24
Advisors：Baoyong Chi
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Research and Design on Wide-Band Reconfigurable Transmitter for SDR Applications
Abstract:
In recent decades, wireless communication technology develops rapidly. It is foreseeable that in the future multi-band, multi-standard, multi-mode, two-way communication and one-way communication will be widely coexisting. End-user demand for applications is constantly increasing, which requires integration of multiple applications in one terminal. Software Defined Radio (SDR) is proposed to solve the problems with the software configuration of hardware circuit. A common, standard, modular hardware platform based on the application of radio programming is used to select the specific application. To solve the contradiction between multiple applications and the integration of hardware, this paper will research on the multi-mode mobile communication transmitter circuits. This work in this thesis is divided into two parts. The first part is to design the broadband transmitter with a frequency coverage range of 1.5G-2.15GHz in SMIC 0.13um CMOS process. The transmitter includes programmable gain amplifier (PGA), the voltage sampling mixer, and the pre-driver stage of power amplifier (PA-Driver). The measured results show that it realizes a 0-20dB gain PGA, the step is 2dB, and the -1dB bandwidth is 50MHz. The output 1dB compression point O1dB of the transmitter over 1.5G-2.15GHz is higher than 0dBm, the chip area is 1.6mm * 1.2mm, and the supply voltage is 1.2V, with the power of 42mW. This version of the transmitter confirmed the accuracy modeling of the on-chip transformer, as well as good broadband characteristics when transformers and variable capacitance is used as the load of the PA-Driver. In the second part of the thesis, it tries to achieve a transmitter covering 200M-6GHz frequency range, the output power is higher than 0dBm, and broadband output impedance matching to achieve the maximum power transmission efficiency when connecting with the power amplifier (PA). The two-stage PGA in the transmitter achieves 0-30dB gain, with the step of 2dB, and 4.3dBm of the output 1dB compression point. Compare with the traditional Gilbert cell, voltage sampling mixer will achieve better linearity and noise performance if it is biased reasonable. The up-converted RF signal will be sent to the pre-driver stage of power amplifier (PA-Driver), the PA-Driver amplifies radio frequency signal, while implementing the output impedance matching to achieve high power transfer efficiency. Different from the above transmitter, the PA-Driver with the load of on-chip transformer and variable capacitor arrays shows better performance in size and tolerance to process variation. The post-layout simulation results show that the transmitter output 1dB compression point in the whole frequency range of 200MHz~6GHzis higher than 0dBm; the output third order intercept point is more than 9dBm.