对S波段的色散补偿型分布式光纤拉曼放大器(FRA)进行了研制。本放大器中采用了先进的光纤拉曼激光器作为抽运源,并对5 km DCF-50 km G652光纤色散补偿型分布式FRA分别进行了前向抽运和后向抽运,测量了其前向和后向增益光谱和噪声谱,结...对S波段的色散补偿型分布式光纤拉曼放大器(FRA)进行了研制。本放大器中采用了先进的光纤拉曼激光器作为抽运源,并对5 km DCF-50 km G652光纤色散补偿型分布式FRA分别进行了前向抽运和后向抽运,测量了其前向和后向增益光谱和噪声谱,结果表明后向抽运方式在增益和噪声特性方面优于前向抽运方式。对色散补偿型分布式FRA在后向抽运方式下的增益和噪声指数随抽运功率的变化而变化的规律进行了实验研究,结果表明其增益随抽运功率的增大而增大,噪声指数随增益的增大而减小。为比较色散补偿型分布式FRA和分布式FRA在增益和噪声方面的性能,分别测量了上述两种光纤拉曼放大器在后向抽运方式下的增益谱和噪声指数谱,结果表明: 5 km DCF-50 km G652光纤制成的色散补偿型分布式FRA的增益和噪声特性,均优于由50km-G652光纤制成的分布式FRA。本文对实验结果进行了理论分析。展开更多
A novel wide-range CMOS variable gain amplifier （VGA） topology is presented. The proposed VGA is composed of a variable transconductor and a novel variable output resistor and can offer a high gain variation range o...A novel wide-range CMOS variable gain amplifier （VGA） topology is presented. The proposed VGA is composed of a variable transconductor and a novel variable output resistor and can offer a high gain variation range of 80dB while using a single variable-gain stage. Temperature-compensation and decibel-linear gain characteristic are achieved by using a control circuit that provides a gain error lower than ±1.5dB over the full temperature and gain ranges. Realized in 0.25μm CMOS technology, a prototype of the proposed VGA provides a total gain range of 64.5dB with 55.6dB-linear range,a P-1dB varying from - 17.5 to 11.5dBm,and a 3dB-bandwith varying from 65 to 860MHz while dissipating 16.5mW from a 2.5V supply voltage.展开更多
Based on the minimum settling time （MST） theory and step-response analysis of the second order system in active switched capacitor （SC） networks, a novel clock feedthrough frequency compensation （CFFC） method fo...Based on the minimum settling time （MST） theory and step-response analysis of the second order system in active switched capacitor （SC） networks, a novel clock feedthrough frequency compensation （CFFC） method for a folded-cascode OTA is proposed. The damping factor r/is adjusted by using MOS capacitors to introduce clock feedthrough so that the OTA can obtain the MST state and thus achieve fast settling. Research results indicate that the settling time of the compensated OTA is reduced by 22.7% ;as the capacitor load varies from 0.5 to 2.5pF,the improved settling time increases approximately linearly from 3.62 to 4.46ns： for VGA application, fast settling can also be achieved by modifying the MOS capacitor value accordingly when the closed loop gain of the compensated OTA varies.展开更多
A new frequency compensation technique for low-power, area-efficient multistage amplifiers is introduced. Using nested active capacitors, our scheme achieves better bandwidth-to-power and slew-rate-to-power performanc...A new frequency compensation technique for low-power, area-efficient multistage amplifiers is introduced. Using nested active capacitors, our scheme achieves better bandwidth-to-power and slew-rate-to-power performances than previous works. Implemented in standard 0.35μm CMOS technology, our three-stage amplifier achieves 105dB DC gain, 3.3M GBW,68 phase margin, and 2.56V/μs average slew rate under a 150pF capacitive load. All of these are realized with only 40μW power consumption under a 2V power supply,with very small compensation capacitors.展开更多
研制了一款可编程6阶巴特沃斯有源RC滤波器。为提高滤波器中运算放大器的增益带宽积,设计了一种新型的前馈补偿运算放大器。为消除工艺偏差和环境变化对截止频率的影响,设计了一种片上数字控制频率调谐电路,并采用TSMC 0.18μm CMOS工...研制了一款可编程6阶巴特沃斯有源RC滤波器。为提高滤波器中运算放大器的增益带宽积,设计了一种新型的前馈补偿运算放大器。为消除工艺偏差和环境变化对截止频率的影响,设计了一种片上数字控制频率调谐电路,并采用TSMC 0.18μm CMOS工艺进行了流片。滤波器采用低通滤波结构,测试结果表明,3 d B截止频率为1 32 MHz,步进1 MHz,带内增益0 d B,带内纹波0.8 d B,2倍带宽处带外抑制不小于24 d Bc,5倍带宽处带外抑制不小于68 d Bc,滤波器等效输入噪声为槡340 n V/Hz@1 MHz,调谐误差为±3%。滤波器裸芯片面积0.87 mm×1.05 mm。采用1.8 V电源电压,滤波器整体功耗小于20 m W。展开更多
This paper presents a three-stage CMOS operational amplifier （opamp） that combines accuracy with stability for a wide range of capacitive loads. A so-called quenching capacitor is added to a multipath nested Miller ...This paper presents a three-stage CMOS operational amplifier （opamp） that combines accuracy with stability for a wide range of capacitive loads. A so-called quenching capacitor is added to a multipath nested Miller compensation （MNMC） topology to obtain stability for a wide range of capacitive loads. Theoretical analysis and mathematical formulas are provided to prove the improvement in stability. A prototype of this frequency compen- sation scheme is implemented in a 0.7μm CMOS process. Measurement′s show that the amplifier can drive capaci- tive loads ranging from 100pF to 100/μF with a gain of 90dB and a minimum phase margin of 26°. The amplifier has a unity-gain bandwidth of 1MHz for a 100pF capacitive load. It employs a quenching capacitance of 18pF.展开更多
An S band and a C band distributed fiber Raman amplifiers (DFRAs) with flattened gain and compensated dispersion have been studied and implemented with 1427 nm and 1455 nm mono-wavelength fiber Raman lasers as the pum...An S band and a C band distributed fiber Raman amplifiers (DFRAs) with flattened gain and compensated dispersion have been studied and implemented with 1427 nm and 1455 nm mono-wavelength fiber Raman lasers as the pumped sourcesrespectively. The gain of single-wave pumped S band and C band can reach 10 dB and 15 dB respectively. And a 50 nmgain flattened width was successfully obtained by using a chirp fiber Bragg grating (CFBG) gain flattened filter with gainripple of ±0.6 dB. The C band DFRA has been applied to CDMA wireless communication system successfully.展开更多
A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consis...A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consists of 6 seriesparallel amplifiers as delay units and 7 Gilbert variable gain amplifiers as taps,which ensure that the equalizer can work at the bit rate of 10 Gb/s.With different tap gains,the forward voltage gain of the transversal equalizer varies,which demonstrates that the equalizer has various filtering characteristics such as low pass filtering,band pass filtering,band reject filtering,and notch filtering,so it can effectively simulate the inverse transfer function of dispersive channels in optical communications,and can be used for compensating the inter-symbol interference and other nonlinear problems caused by dispersion.The equalizer(including pads) occupies an area of 0.40 mm × 1.08 mm,and its total power dissipation is 400 mW with 3.3 V power supply.展开更多
文摘对S波段的色散补偿型分布式光纤拉曼放大器(FRA)进行了研制。本放大器中采用了先进的光纤拉曼激光器作为抽运源,并对5 km DCF-50 km G652光纤色散补偿型分布式FRA分别进行了前向抽运和后向抽运,测量了其前向和后向增益光谱和噪声谱,结果表明后向抽运方式在增益和噪声特性方面优于前向抽运方式。对色散补偿型分布式FRA在后向抽运方式下的增益和噪声指数随抽运功率的变化而变化的规律进行了实验研究,结果表明其增益随抽运功率的增大而增大,噪声指数随增益的增大而减小。为比较色散补偿型分布式FRA和分布式FRA在增益和噪声方面的性能,分别测量了上述两种光纤拉曼放大器在后向抽运方式下的增益谱和噪声指数谱,结果表明: 5 km DCF-50 km G652光纤制成的色散补偿型分布式FRA的增益和噪声特性,均优于由50km-G652光纤制成的分布式FRA。本文对实验结果进行了理论分析。
文摘A novel wide-range CMOS variable gain amplifier （VGA） topology is presented. The proposed VGA is composed of a variable transconductor and a novel variable output resistor and can offer a high gain variation range of 80dB while using a single variable-gain stage. Temperature-compensation and decibel-linear gain characteristic are achieved by using a control circuit that provides a gain error lower than ±1.5dB over the full temperature and gain ranges. Realized in 0.25μm CMOS technology, a prototype of the proposed VGA provides a total gain range of 64.5dB with 55.6dB-linear range,a P-1dB varying from - 17.5 to 11.5dBm,and a 3dB-bandwith varying from 65 to 860MHz while dissipating 16.5mW from a 2.5V supply voltage.
文摘Based on the minimum settling time （MST） theory and step-response analysis of the second order system in active switched capacitor （SC） networks, a novel clock feedthrough frequency compensation （CFFC） method for a folded-cascode OTA is proposed. The damping factor r/is adjusted by using MOS capacitors to introduce clock feedthrough so that the OTA can obtain the MST state and thus achieve fast settling. Research results indicate that the settling time of the compensated OTA is reduced by 22.7% ;as the capacitor load varies from 0.5 to 2.5pF,the improved settling time increases approximately linearly from 3.62 to 4.46ns： for VGA application, fast settling can also be achieved by modifying the MOS capacitor value accordingly when the closed loop gain of the compensated OTA varies.
文摘A new frequency compensation technique for low-power, area-efficient multistage amplifiers is introduced. Using nested active capacitors, our scheme achieves better bandwidth-to-power and slew-rate-to-power performances than previous works. Implemented in standard 0.35μm CMOS technology, our three-stage amplifier achieves 105dB DC gain, 3.3M GBW,68 phase margin, and 2.56V/μs average slew rate under a 150pF capacitive load. All of these are realized with only 40μW power consumption under a 2V power supply,with very small compensation capacitors.
文摘研制了一款可编程6阶巴特沃斯有源RC滤波器。为提高滤波器中运算放大器的增益带宽积,设计了一种新型的前馈补偿运算放大器。为消除工艺偏差和环境变化对截止频率的影响,设计了一种片上数字控制频率调谐电路,并采用TSMC 0.18μm CMOS工艺进行了流片。滤波器采用低通滤波结构,测试结果表明,3 d B截止频率为1 32 MHz,步进1 MHz,带内增益0 d B,带内纹波0.8 d B,2倍带宽处带外抑制不小于24 d Bc,5倍带宽处带外抑制不小于68 d Bc,滤波器等效输入噪声为槡340 n V/Hz@1 MHz,调谐误差为±3%。滤波器裸芯片面积0.87 mm×1.05 mm。采用1.8 V电源电压,滤波器整体功耗小于20 m W。
文摘This paper presents a three-stage CMOS operational amplifier （opamp） that combines accuracy with stability for a wide range of capacitive loads. A so-called quenching capacitor is added to a multipath nested Miller compensation （MNMC） topology to obtain stability for a wide range of capacitive loads. Theoretical analysis and mathematical formulas are provided to prove the improvement in stability. A prototype of this frequency compen- sation scheme is implemented in a 0.7μm CMOS process. Measurement′s show that the amplifier can drive capaci- tive loads ranging from 100pF to 100/μF with a gain of 90dB and a minimum phase margin of 26°. The amplifier has a unity-gain bandwidth of 1MHz for a 100pF capacitive load. It employs a quenching capacitance of 18pF.
基金This work was supported by Great Scientific Research Project ofZhejiang Province, China (No.021101558)a part of projectfunds of the Korea-China Optical Technology Research Center.
文摘An S band and a C band distributed fiber Raman amplifiers (DFRAs) with flattened gain and compensated dispersion have been studied and implemented with 1427 nm and 1455 nm mono-wavelength fiber Raman lasers as the pumped sourcesrespectively. The gain of single-wave pumped S band and C band can reach 10 dB and 15 dB respectively. And a 50 nmgain flattened width was successfully obtained by using a chirp fiber Bragg grating (CFBG) gain flattened filter with gainripple of ±0.6 dB. The C band DFRA has been applied to CDMA wireless communication system successfully.
基金supported by the Natural Science Foundation of Hebei Province (No.F2008000116)
文摘A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consists of 6 seriesparallel amplifiers as delay units and 7 Gilbert variable gain amplifiers as taps,which ensure that the equalizer can work at the bit rate of 10 Gb/s.With different tap gains,the forward voltage gain of the transversal equalizer varies,which demonstrates that the equalizer has various filtering characteristics such as low pass filtering,band pass filtering,band reject filtering,and notch filtering,so it can effectively simulate the inverse transfer function of dispersive channels in optical communications,and can be used for compensating the inter-symbol interference and other nonlinear problems caused by dispersion.The equalizer(including pads) occupies an area of 0.40 mm × 1.08 mm,and its total power dissipation is 400 mW with 3.3 V power supply.
