Small‐Sized High‐Power PIN Diode Switch with Defected Ground Structure for Wireless Broadband Internet

This letter presents a small‐sized, high‐power single‐pole double‐throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow‐wave characteristic, the DGS is used for the quarter‐wave (°/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt‐connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt‐type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.     

异质结光晶体管的研究与进展

回顾了异质结光晶体管(HPT)在近年来的重要进展,综合分析了HPT的工作原理以及影响其性能的主要参数。综述了不同材料制作的HPT的研究现状,得出了目前限制HPT发展的主要因素及当前应重点解决由于基区表面复合等效应导致的增益下降和由于结电容的充放电限制的响应带宽等问题的结论。     

SOI光电子集成

SOI（Silicon-on-Insulator)光电子集成已成为十分引人注目的研究课题，其工艺与CMOS工艺完全兼容，可以实现低成本的SOI基整片集成光电子回路。本文综述了近几年来SOI集成光电子器件的发展以及一些最新的研究进展，着重分析几种最新型光无源器件的工作原理和结构，包括SOI光波导、SOI光波导耦合器、SOI光波导开关、相位阵列波导光栅（PAWG）、基于SOI的光探测器等，并介绍了中国科学院半导体所集成光电子国家重点实验室的研究进展。     

QUANTUM MECHANICAL MODEL AND SIMULATION OF GaAs/AlGaAs QUANTUM WELL INFRARED PHOTO- DETECTOR-Ⅰ OPTICAL ASPECTS

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｆｒａｒｅｄｄｅｔｅｃｔｏｒｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎａｋｅｙｆａｃｔｏｒｉｎｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅｉｎｆｒａｒｅｄｔｅｃｈｎｏｌｏｇｙｆｏｒｍｏｒｅｔｈａｎ 4 0 ｙｅａｒｓ .Ｓｉｎｃｅ 1970 ,ｓｅｍｉｃｏｎｄｕｃｔｏｒｓｌｉｋｅＩｎＳｂａｎｄＨｇＣｄＴｅｈａｖｅｂｅｅｎｔｈｅｐｒｉｎｃｉｐａｌｍａｔｅｒｉａｌｓｆｏｒｖａｒｉｏｕｓｉｎｆｒａｒｅｄｄｅｔｅｃｔｏｒａｐｐｌｉｃａｔｉｏｎｓ .Ｔｈｅｆｏｒｍａｔｏｆｔｈｅｉｎｆｒａｒｅｄｄｅｔｅｃｔｏｒｍｏｔｉｖａｔｅｄｂｙｓｍａｒｔｔｈｅｒｍａｌｉｍａｇｉｎｇｓｙｓｔｅｍｃｈａｎｇｅｄｆｒｏｍｓｉｎｇｌｅｅｌｅｍｅｎｔｄｅｖｉｃｅｔｏｆｏｃａｌｐｌａｎａｒｒａｙｓ(ＦＰＡｓ)ｉｎｔｈｅｍｉｄｄｌｅｏｆ 80’ｓ [1].Ｔｏｄａｙ’ｓｔｅｃｈｎｏｌｏｇｙｏｆｉｎｆｒａｒｅｄｄｅｔｅｃｔｏｒｃｏｎｃｅｎｔｒａｔｅｓｌａｒｇｅｌｙｏｎｆｏｃａｌｐｌａｎａｒｒａｙｓ ,ｅｘｐｅｃｉａｌｌｙｆｏｒｓｅｎｓｉｔｉｖｅ ,ｈｏｍｏｇｅｎｅｏｕｓａｎｄｌａｒｇｅｆｏｒｍａｔｓｃａｌｅｄｅｖｉｃｅｓ .ＨｇＣｄＴｅ...     

MEMS移相器及其在微型通信系统中的应用

从传统移相器的构造和原理出发，进一步分析了MEMS移相器的结构、特性。结果表明，MEMS移相器具有传统移相器所无法比拟的体积小、损耗小、成本低、频带宽、易于集成等突出优点。随着高阻硅衬底在微波领域应用的扩展，MEMS移相器介质损耗大幅度降低，将能与信号处理电路一同集成于硅衬底上，便于相控阵雷达等通信系统实现微小型化。     

InxGa1−xAs (x=0.25–0.35) grown at low temperature

In_xGa_1−xAs (x=0.25–0.35) grown at low temperature on GaAs by molecular beam epitaxy is characterized by Hall effect, transmission electron microscopy, and ultrafast optical testing. As with low temperature (LT) GaAs, the resistivity is generally higher after a brief anneal at 600°C. High-resolution transmission electron microscopy shows all the as-grown epilayers to be heavily dislocated due to the large lattice mismatch (2–3%). When the layers are annealed, in addition to the dislocations, precipitates are also generally observed. As with LT-GaAs, the lifetime shortens as growth temperature is reduced through the range 300–120°C; also, the lifetime in LT-In_xGa_1−xAs is generally shorter in as-grown samples relative to annealed samples. Metal-semiconductor-metal photodetectors fabricated on the material exhibit response times of 1–2 picoseconds, comparable to results reported on GaAs grown at low temperature, and the fastest ever reported in the wavelength range of 1.0–1.3 μm.     

量子阱红外探测器能带结构的计算

利用电子波在阱与垒的界面上的反射及干涉效应，计算了量子阱红外探测器(QWIP)的能带结构，并对其适用性进行了分析和讨论。通过与K-P模型比较发现，本方法对计算较宽势阱(阱宽大于4nm)的量子阱结构的电子态适合。在垒宽和阱宽不变条件下，用两种方法计算得到的AlGaAs／GaAs量子阱材料中Al组分x与吸收峰值波长λp的关系曲线基本相同。结果说明，在较宽的范围内，本方法对QWIP能带结构的计算是适用且简便的。     

单片InGaAs／InP PIN PD阵列

文章简要地介绍了ＩｎＧａＡｓ／ＩｎＰ ＰＩＮ ＰＤ阵列的制作现状及其应用和发展趋势。     

Ultraviolet-visible metal-semiconductor-metal photodetectors fabricated from InxGa1−xN (0≤x≤0.13)

Metal-semiconductor-metal (MSM) photodetectors have been fabricated on In_xGa_1−xN epitaxial films grown by metalorganic chemical vapor deposition within the composition range 0≤x≤0.13. The dark current and spectral response were measured for devices with a varying In mole fraction x. The devices, which had nominal finger widths and finger spacing of 5 μm, were biased with modest voltages in the range 2≤V_bias≤5 V. In general, turn-on wave-length and dark current increased with increasing x. Turn-on wavelengths ranged from λ=370 nm to 430 nm and dark current densities ranged from I_dark=2×10⁻² A/cm² (V_bias=5 V, x≈0.05) to 9×10⁴ A/cm² (V_bias=2 V, x≈0.13) depending on the In content, x, of the device active area.     

CMOS兼容近红外Si0.7Ge0.3/Si p-i-n(SOI)光电探测器

报道了一种采用UHV/CVD锗硅工艺和CMOS工艺流程在SOI衬底上制作的横向叉指状Si0.7Ge0.3/Si p-i-n光电探测器.测试结果表明:其工作波长范围为0.7～1.1μm,在峰值响应波长为0.93μm,响应度为0.38A/W.在3.0V的偏压下,其暗电流小于1nA,寄生电容小于1.0pF,上升时间为2.5ns.其良好的光电特性以及与CMOS工艺的兼容性,为研制能有效工作于近红外光的高速、低工作电压硅基光电集成器件提供了一种新的尝试,在高速光信号探测等应用中有一定的价值.