适用于双载波正交频分复用超宽带系统的数据转换器设计  

Design of Data Converters for Dual-carrier Orthogonal Frequency-Division Multiplexing Ultra-wideband System

作　　者：夏杰峰[1] 哈钱钱[1] 林宇婧[1] 叶凡[1] 任俊彦[1] 

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室,上海201203

出　　处：《复旦学报（自然科学版）》2012年第6期722-728,共7页Journal of Fudan University：Natural Science

基　　金：国家科技重大专项计划资助项目(2011ZX03004-001-02;2009ZX03006-007-01)

摘　　要：国家超宽带(UWB)标准采用了双载波正交频分复用技术(DC-OFDM),此设计基于该标准的超宽带系统中用数据转换器,包括一个单片集成4通道650MS/s 8bit电流舵数模转换器(DAC)和一个单片集成4通道300MS/s 6bit折叠内插模数转换器(ADC),在印刷电路板(PCB)上实现集成.DAC设计着重考虑电流源的匹配,并且采用降摆幅电路提高动态性能,当输入频率为68MHz时,单个子DAC无杂散动态范围(SFDR)可以达到51dB以上;ADC采用级间流水线开关降低放大器建立要求,采用有源内插进一步降低比较器失调影响,单个子ADC信噪失真比(SNDR)在整个奈奎斯特频带内都保持在32dB以上.Dual-carrier orthogonal frequency-division multiplexing（DC-OFDM） is adopted in China as the ultra-wideband（UWB） national standard.Two data converters are designed based on this UWB system standard,including a four-channel 650 MS/s 8 bit current-steering digital-to-analog converter（DAC） and a four-channel 300 MS/s 6 bit folding-and-interpolating analog-to-digital converter（ADC）.Both of them are integrated on a printed circuit board（PCB）.The DAC has focused on the matching of current sources and its dynamic performance is improved by reducing the voltage swing of the switch transistors.Testing result shows that one sub-DAC can achieve over 52 dB spurious-free dynamic range（SFDR） locating at 68 MHz input.The ADC adopts inter-stage pipelined switches to relax amplifiers＇ bandwidth,utilizes active interpolators to further mitigate the offset of the comparators and keeps the signal-to-noise-and-distortion ration（SNDR） of sub-ADC over 32 dB in the entire Nyquist band.

关 键 词：超宽带 双载波正交频分复用 数模转换器 模数转换器 电流舵 折叠内插 

分 类 号：TN402[电子电信—微电子学与固体电子学]