980 nm InGaAs/GaAs separate confinement heterostructure （SCH） strained quantum well （QW） laser with non-absorbing facets was fabricated by using thermal treatment. Microchannel coolers with a five-layer thin oxyge...980 nm InGaAs/GaAs separate confinement heterostructure （SCH） strained quantum well （QW） laser with non-absorbing facets was fabricated by using thermal treatment. Microchannel coolers with a five-layer thin oxygen-free copper plate structure were designed and fabricated through thermal bonding in hydrogen ambient. The highest CW （continuous wave） output power of 200 W for 5-bar arrays packaged by microchannel coolers was presented.展开更多
In order to realize further stability of a stack-type thermoelectric power generating module (i.e. no electrical connections inside), flexible materials of metal springs and/or rods having restoring forces were instal...In order to realize further stability of a stack-type thermoelectric power generating module (i.e. no electrical connections inside), flexible materials of metal springs and/or rods having restoring forces were installed between lower-temperature-sides of thermoelectric elements. These flexible materials were expected to play three important roles of interpolating different thermal expansions of the module components, enlarging heat removal area and penetration of any media through themselves. Then, a low-boiling-point medium (i.e. NOVEC manufactured by 3M Japan Ltd.) was also applied for a high-speed direct heat removal via its phase change from the lower-temperature-sides of the thermoelectric elements in the proposing stack-type thermoelectric power generating module. No electrical disconnections inside the module were confirmed for more than 9 years of use, indicating further module stability. The power generating density was improved to about 120 mW·m-2 with SUS304 springs having 0.7 mm diameter. Increasing power generating density can be expected in terms of suitable selection of flexible metal with high Vickers hardness, cavities control on the spring surface, more vigorous multiphase flow with adding powders to the medium and optimization of the module configurations according to numerical simulations.展开更多
Operation of 808-nm laser diode pumping at elevated temperature is crucial to many applications. Reliable operation at high power is limited by high thermal load and low catastrophic optical mirror damage (COMD) thres...Operation of 808-nm laser diode pumping at elevated temperature is crucial to many applications. Reliable operation at high power is limited by high thermal load and low catastrophic optical mirror damage (COMD) threshold at elevated temperature range. We demonstrated high efficiency and high power operation at elevated temperature with high COMD power. These results were achieved through device design optimization such as growth conditions, doping profile, and materials composition of the quantum-well and other layers. Electrical-to-optical efficiency as high as 62% was obtained through lowered threshold current, lowered series resistance and increased slope efficiency. The performance of single broad-area laser diodes scales to that of high power single bars on water-cooled copper micro-channel heatsinks or conductively-cooled CS heatsinks. No reduction in bar performance or significant spectral broadening is seen when these micro-channel coolers are assembled into 6-bar and 18-bar CW stacks for the highest power levels.展开更多
基于TSMC 0.13μm CMOS工艺设计了一款适用于无线传感网络、工作频率为300~400 MHz的两级功率放大器。功率放大器驱动级采用共源共栅结构,输出级采用了3-stack FET结构,采用线性化技术改进传统偏置电路,提高了功率放大器线性度。电源电...基于TSMC 0.13μm CMOS工艺设计了一款适用于无线传感网络、工作频率为300~400 MHz的两级功率放大器。功率放大器驱动级采用共源共栅结构,输出级采用了3-stack FET结构,采用线性化技术改进传统偏置电路,提高了功率放大器线性度。电源电压为3.6 V,芯片面积为0.31 mm×0.35 mm。利用Cadence Spectre RF软件工具对所设计的功率放大器电路进行仿真,结果表明,工作频率为350 MHz时,功率放大器的饱和输出功率为24.2 d Bm,最大功率附加效率为52.5%,小信号增益达到38.15 d B。在300~400 MHz频带内功率放大器的饱和输出功率大于23.9 d Bm,1 d B压缩点输出功率大于22.9 d Bm,最大功率附加效率大于47%,小信号增益大于37 d B,增益平坦度小于±0.7 d B。展开更多
文摘980 nm InGaAs/GaAs separate confinement heterostructure （SCH） strained quantum well （QW） laser with non-absorbing facets was fabricated by using thermal treatment. Microchannel coolers with a five-layer thin oxygen-free copper plate structure were designed and fabricated through thermal bonding in hydrogen ambient. The highest CW （continuous wave） output power of 200 W for 5-bar arrays packaged by microchannel coolers was presented.
文摘In order to realize further stability of a stack-type thermoelectric power generating module (i.e. no electrical connections inside), flexible materials of metal springs and/or rods having restoring forces were installed between lower-temperature-sides of thermoelectric elements. These flexible materials were expected to play three important roles of interpolating different thermal expansions of the module components, enlarging heat removal area and penetration of any media through themselves. Then, a low-boiling-point medium (i.e. NOVEC manufactured by 3M Japan Ltd.) was also applied for a high-speed direct heat removal via its phase change from the lower-temperature-sides of the thermoelectric elements in the proposing stack-type thermoelectric power generating module. No electrical disconnections inside the module were confirmed for more than 9 years of use, indicating further module stability. The power generating density was improved to about 120 mW·m-2 with SUS304 springs having 0.7 mm diameter. Increasing power generating density can be expected in terms of suitable selection of flexible metal with high Vickers hardness, cavities control on the spring surface, more vigorous multiphase flow with adding powders to the medium and optimization of the module configurations according to numerical simulations.
文摘Operation of 808-nm laser diode pumping at elevated temperature is crucial to many applications. Reliable operation at high power is limited by high thermal load and low catastrophic optical mirror damage (COMD) threshold at elevated temperature range. We demonstrated high efficiency and high power operation at elevated temperature with high COMD power. These results were achieved through device design optimization such as growth conditions, doping profile, and materials composition of the quantum-well and other layers. Electrical-to-optical efficiency as high as 62% was obtained through lowered threshold current, lowered series resistance and increased slope efficiency. The performance of single broad-area laser diodes scales to that of high power single bars on water-cooled copper micro-channel heatsinks or conductively-cooled CS heatsinks. No reduction in bar performance or significant spectral broadening is seen when these micro-channel coolers are assembled into 6-bar and 18-bar CW stacks for the highest power levels.
文摘基于TSMC 0.13μm CMOS工艺设计了一款适用于无线传感网络、工作频率为300~400 MHz的两级功率放大器。功率放大器驱动级采用共源共栅结构,输出级采用了3-stack FET结构,采用线性化技术改进传统偏置电路,提高了功率放大器线性度。电源电压为3.6 V,芯片面积为0.31 mm×0.35 mm。利用Cadence Spectre RF软件工具对所设计的功率放大器电路进行仿真,结果表明,工作频率为350 MHz时,功率放大器的饱和输出功率为24.2 d Bm,最大功率附加效率为52.5%,小信号增益达到38.15 d B。在300~400 MHz频带内功率放大器的饱和输出功率大于23.9 d Bm,1 d B压缩点输出功率大于22.9 d Bm,最大功率附加效率大于47%,小信号增益大于37 d B,增益平坦度小于±0.7 d B。
