Biography

Enrollment Date: 2008

Graduation Date：2011

Degree：M.S.

Defense Date：2011.05.24

Advisors：Woogeun Rhee

Department：Institute of Microelectronics，Tsinghua University

Title of Dissertation/Thesis：A study on multi-phase triangular waveform generator for FM-UWB transmitter

Abstract:
Triangular waveform generation plays an important role in modern communication system. It is useful in spread-spectrum clock generation and ultra-wideband systems, in which the voltage controlled oscillator is directly modulated, for the spectrum modulated by triangular waveform is flatter than by sinusoidal signal. This thesis focuses on the development of triangular waveform generator for FM-UWB transmitter. This thesis is on the realization of triangular waveform by analog circuit, which is based on relaxation oscillator. Traditional sub-carrier loop of FM-UWB transmitter is consisted of digital circuit. Although it has several advantages, it could not satisfy the application with high data-rate, because the triangular waveform is generated by accumulator, whose performance is limited by the over sampling rate (OSR). In another hand, the existing analog triangular waveform generators have some disadvantages and no existing architectures could generate multi-phase output. In the thesis, a differential relaxation VCO with amplitude control is implemented for FM-UWB transmitter with 1Mbps data rate. It is verified by testing. In addition, this thesis presents a CMOS voltage-controlled oscillator (VCO) which enables eight-phase triangular waveform generation. The first stage consists of two charge-discharged circuits, which is similar to two conventional relaxation oscillators with cross-coupled connection, and is used to generate quad-signals. By utilizing a cascaded relaxation oscillator core followed by a pseudo injection-locked oscillator circuit, an eight-phase differential VCO with triangular waveform outputs is realized. For the sub-carrier is based on DSM-PLL, the multi-phase output would be benefit for the suppression of quantization noise. Simulation results show that the proposed fully differential multi-phase VCO can achieve broad tuning range with programmable timing capacitors and low phase mismatch. The testing is in progress

Publications

Papers：：

[1] Hang Lv,Bo Zhou,Dang Liu,Woogeun Rhee,Yongming Li,Zhihua Wang, A 5.2–11.8MHz octa-phase relaxation oscillator for 8-PSK FM-UWB transceiver systems, VLSI-DAT 2013, pp. 1 - 4, 2013.

[2] Bo Zhou,Jian Qiao,Rui He,Jinghui Liu,Wei Zhang,Hang Lv,Woogeun Rhee,Yongming Li,Zhihua Wang, A Gated FM-UWB System With Data-Driven Front-End Power Control, IEEE Transactions on Circuits and Systems I-Regular Papers, Vol.59, No.6, pp. 1348 - 1358, 2012.

[3] Yuanfeng Sun,Jun Li,Zhuo Zhang,Min Wang,Ni Xu,Hang Lv,Woogeun Rhee,Yongming Li,Zhihua Wang, A 2.74–5.37GHz boosted-gain type-I PLL with <15% loop filter area, RFIC 2012, pp. 181 - 184, 2012.

[4] Bo Zhou,Hang Lv,Min Wang,Jinghui Liu,Woogeun Rhee,Yongming Li,Dongwook Kim,Zhihua Wang, A 1Mb/s 3.2–4.4GHz reconfigurable FM-UWB transmitter in 0.18μm CMOS, RFIC 2011, pp. 1 - 4, 2011.

[5] Hang Lv,Bo Zhou,Woogeun Rhee,Yongming Li,Zhihua Wang, A Relaxation Oscillator with Multi-Phase Triangular Waveform Generation, ISCAS 2011, pp. 2837 - 2840, 2011.