摘要：A gallium nitride(GaN)power amplifier monolithic microwave integrated circuit(MMIC)with a wide band and high efficiency in the microwave frequency band is proposed in this *** power amplifier MMIC uses a 0.15^im GaN high electron mo-bility transistor(HEMT)*** operating frequency band of the amplifier can cover the whole K-band,i.e.,17-26.5 GHz.

摘要：A Y-band frequency doubler is analyzed and designed with GaAs planar Schottky diode,which is flip-chip solded into a 50|xm thick quartz *** embedding impedance is found by fullwave analysis with lumped port to model the nonlinear junction for impedance matching without the need of diode equivalent circuit *** the matching circuit is designed 'on-chip' and the multiplier is *** the doubler,a conversion efficiency of 6.1%and output power of 5.4mW are measured at 214 GHz with input power of 88 mW,and the typical measured efficiency is 4.5%in200~225GHz.

摘要：A 4H-SiC MOSFET with breakdown voltage higher than 3300 V has been successfully designed and fabricated. Numerical simulations have been performed to optimize the parameters of the drift layer and DMOSFET cell structure of active area. The n-type epilayer is 33μm thick with a doping of 2.5 × 10^15 cm-3. The devices were fabricated with a floating guard ring edge termination. The drain current 1d= 5 A at Vg = 20 V, corresponding to vd = 2.5 v.

摘要：Freeform optical surfaces （FOSs） will be the best elements in the design of compact optical systems in the future. However, it is extremely difficult to measure freeform surface with sufficient accuracy, which im- pedes the development of the freeform surface. The design and fabrication of computer-generated hologram （CGH） , which has been successfully applied to the tests for aspheric surfaces, cannot be directly adopted to test FOSs due to their non-rotational asymmetry. A novel ray tracing planning method combined with successively optimizing even and odd power coefficients of phase polynomials in turn is proposed, which can successfully design a non-rotational asymmetry CGH for the tests of FOSs with an F-O lens. A new eight-step fabrication process is also presented aiming to solve the problem that the linewidth on the same circle of the CGH for testing freeform surface is not uniform. This problem cannot be solved in the original procedure of CGH fabrication. The test results of the step profiler show that the CGH fabricated in the new nrocedure meets the reauirements.

摘要：三维(3D)狄拉克半金属因其独特的拓扑能带结构及优异的光电性能在中/远红外波段的宽光谱光电探测领域具有巨大的应用潜力.然而,由于较大的暗电流,构建具有高信噪比(SNR)的3D狄拉克半金属宽光谱光电探测器仍面临很大挑战.本工作基于分子束外延生长的(Cd_(1-x)Zn_(x))_(3)As_(2)薄膜发展了一种超低器件噪声的3 D狄拉克半金属(Cd_(1-x)Zn_(x))_(3)As_(2)/Sb_(2)Se_(3)背靠背异质结光电探测器线阵.得益于有效的双异质结设计策略,该探测器可以实现从可见光(450 nm)到中红外(4.5μm)波段的室温高性能宽光谱探测器目标,其峰值SNR和D*分别可达104和5.2×10^(12)Jones,并具有相对较快的响应速度(~87.5μs).此外,不同探测器线列单元之间呈现出的稳定性、均匀性特征表明了其在未来应用于光迹实时跟踪等光电子器件中的可行性.该研究为基于3D狄拉克半金属材料制备具有超高SNR的高速宽光谱光电探测器提供了参考策略,展示了半金属在高速非制冷红外焦平面成像阵列探测器中的广阔前景.

摘要：MXene具有丰富的高电负性末端原子、较大的比表面积和较小的原子厚度等优点,已被用作前驱体制备多种纳米材料.然而,目前已报道的用于衍生金属有机框架(MOF)的MXene仅限于V_(2)CT_(x).因此,通过增加MXene和有机配体的种类,合理设计和合成新型MOF,并进一步深入探索其合成机理仍是目前面临的重要挑战.本文采用金属离子辅助转化策略,以二维Ti_(3)C_(2)T_(x)为前驱体,合成了具有非互穿SrSi2(srs)框架的基于儿茶酚的三维(3D)TiCu-HHTP(HHTP=2,3,6,7,10,11-六羟基三苯)MOF.该策略表现出了良好的普适性,Ti3C2和辅助Cu^(2+)离子可以扩展到V2C MXene和其他辅助金属离子Mn^(+)(M=Ni^(2+)、Co^(2+),Mn^(2+)和Zn^(2+)).转化机制包括从Ti3C2纳米片到辅助金属离子的电荷转移、Ti-C键断裂促进释放Ti^(4+)离子以及Ti^(4+)/Mn^(+)与HHTP之间的强螯合配位协同促进TiCu-HHTP的形成.独特的3D导电网络和丰富的氧化还原位点赋予了TiCu-HHTP-7/PPy复合柔性透明电极快速的离子/电子传输和可逆的法拉第反应.在0.02 mA cm^(-2)电流密度下,TiCu-HHTP/PPy透明电极的面积比电容值达到3.63 mF cm^(-2),明显高于纯PPy电极的面积电容值(1.79 mF cm^(-2)).TiCu-HHTP/PPy透明电容器在0.75μW cm^(-2)的功率密度下,能量密度为0.042μWh cm^(-2).