Edge-coupled InGaAs PIN photodiode with a light funnel waveguide

We have successfully fabricated InGaAs edge-coupled photodiodes (EC-PDs) with a light funnel integrated (LIFI) in front of the coupling aperture, called LIFI EC-PD, based on the self-terminated oxide polish (STOP), the crystallographic slope etching of InP, and the self-aligned diffusion (SAD) techniques. The LIFI EC-PD presents not only a lower dark current density (/spl sim/ 4.4 mA/cm/sup 2/) but also a higher responsivity (/spl sim/ 0.4 A/W) than that of the mesa EC-PD (27 mA/cm/sup 2/ and 0.26 A/W, respectively). Furthermore, the thick oxide film serves as the funnel in front of active-region aperture to enhance the coupling efficiency and to lower the bonding pad capacitance down to 50 fF. The lowered bonding pad capacitance can be beneficial in designing a device with a higher transit-time-limited frequency response of beyond 30 GHz. The LIFI EC-PD with a 1-/spl mu/m thick absorption layer exhibits a 3-dB bandwidth of 20 GHz and a responsivity of /spl sim/ 0.4 A/W.     

A constant-power battery charger with inherent soft switching and power factor correction

A battery charging circuit, which operates as a constant power source, is proposed in this paper. By maintaining a constant output power throughout the charging process, the circuit reduces the size of thermal installation which would normally be required in the cases of constant-voltage or constant-current charging. The proposed circuit takes the form of a half-bridge converter with an additional small inductor and two extra diodes connected in parallel to two dividing capacitors. Constant power delivery is achieved by the discontinuous-voltage-mode operation of the two dividing capacitors, each of which is connected in parallel with a diode. The circuit enjoys low voltage and current stresses, and achieves soft switching with no extra components. When used off-line, the converter maintains a high input power factor and a low level of input current harmonic distortion that meets international regulations. All the above characteristics are determined only by the values of the circuit parameters, the control mechanism being noncritical. A 12 V 65 W prototype was built to demonstrate the merits of this circuit.     

Design and development of optoelectronic mixed signal system-on-package (SOP)

This paper describes the design and development of a 2.5-Gb/s optical transceiver module as a mixed signal SOP for access networks. The module development consists of concurrent design of an optoelectronic package optimizing optical, electrical, thermal, mechanical functions and optical subassembly and RFICs housed in a chip-on-board package. The optical subassembly (OSA) consists of laser and photodiode assembled on a silicon substrate. The transmit and the receiver sections are combined into a single fiber through a polymer coupler on silicon. The splitter between the transmit and receive section is realized using a polymer waveguide. The electronic ICs are assembled on a multilayer organic substrate. The package design includes optical coupling design, impedance matched transmission line design for RF signals, electrical layout design for mixed signals and thermal design for the package. The module is housed in a plastic molded nonhermetic package to achieve low cost packaging. The assembly is completed using passive alignment of optical devices and attachment of electronic devices using adhesives. In this paper, we present the details of the component design and the development of packaging process methods to achieve the design specifications, test results and process guidelines for assembly and integration.     

新型蓄热式高炉煤气加热炉

论述了一种可将高炉煤气等低热值煤气用于工业高温加热炉的新方法。高效蓄热式热回收装置与炉体有机地结合为一体并辅以电子控制系统，可将助燃空气和煤气同时预热至１１００℃，出炉废气温度仅为１５０℃，可降低能耗５０％以上，产量提高３０％。     

LW17A-145单断口瓷柱式SF6断路器系列

对LW17A-145 SF6断路器及HMB-4液压弹簧机构的使用范围、技术参数、结构特点及工作原理等进行了介绍。     

功率变换器电感在直流偏置或矩形波激励时磁损问题研究

结合正弦波激励下的电感磁损模型,研究了直流偏置磁场以及矩形波激励这两种情况对磁损的影响.通过实验揭示了其中的规律,并提出了这两种情况下的磁损计算模型.