提高W-CDMA通信系统容量的技术

文章主要讨论了提高W-CDMA通信系统容量采取的技术,包括:小区间异步操作和3步快速小区搜索、引导符号辅助相干信道估计、基于信干功率比的快速发射功率控制、位置分集、前向链路的发射分集,以及干扰抵消和自适应天线阵列分集接收和发射。     

1.3 /spl mu/m InGaAsN vertical cavity surface emitting lasers grown by MOCVD

The first InGaAsN VCSELs grown by MOCVD with CW lasing wavelength longer than 1.3 /spl mu/m are reported. The devices were of conventional p-i-n structure with doped DBR mirrors. CW lasing up to 65/spl deg/C was observed, with a maximum output power at room temperature of 0.8 mW for multimode devices and nearly 0.3 mW for single-mode devices.     

云计算给业务平台的发展与运维带来的机遇与挑战

通过分析现阶段增值业务平台发展存在的主要问题,结合云计算的特点及优势说明引入云计算技术解决这些问题的机遇,同时探讨随着云计算技术在业务平台领域大规模的应用,在业务平台的运维等方面需要面临的挑战。     

Peering into Alloy Anodes for Sodium‐Ion Batteries: Current Trends,Challenges, and Opportunities

Sodium‐ion batteries (SIBs) are regarded as a complementary technology to lithium‐ion batteries (LIBs) in the effort of searching for alternative energy solutions that are cost‐effective and sustainable. The identification of suitable alternative anode materials is essential to close the gap in energy density between SIBs and LIBs. Solid‐state alloying reactions that work beyond intercalation mechanism are able to provide a significant improvement in specific capacity. This review describes key advances in SIBs with a primary emphasis on alloy anodes. Recent information and results published in the literatures are stressed to provide an overview of their development in SIBs. With the discussion of some of the remaining challenges and possible solutions, the authors hope to sketch out the scope for future studies in this field.     

Transcatheter Self‐Powered Ultrasensitive Endocardial Pressure Sensor

Changes in endocardial pressure (EP) have important clinical significance for heart failure patients with impaired cardiac function. As a vital parameter for evaluating cardiac function, EP is commonly monitored by invasive and expensive cardiac catheterization, which is not feasible for long‐term and continuous data collection. In this work, a miniaturized, flexible, and self‐powered endocardial pressure sensor (SEPS) based on triboelectric nanogenerator (TENG), which is integrated with a surgical catheter for minimally invasive implantation, is reported. In a porcine model, SEPS is implanted into the left ventricle and the left atrium. The SEPS has a good response both in low‐ and high‐pressure environments. The SEPS achieves the ultrasensitivity, real‐time monitoring, and mechanical stability in vivo. An excellent linearity (R ² = 0.997) with a sensitivity of 1.195 mV mmHg^?1 is obtained. Furthermore, cardiac arrhythmias such as ventricular fibrillation and ventricular premature contraction can also be detected by SEPS. The device may promote the development of miniature implantable medical sensors for monitoring and diagnosis of cardiovascular diseases.     

Cross-coupled dual-spiral high-temperature superconducting filter

A microstrip bandpass filter implemented with dual-spiral resonators is described in this letter. The dual-spiral resonators make the filter compact and allow implementation of positive and negative inter-resonator couplings. Implementation of the positive and negative couplings is used to introduce a pair of finite frequency transmission-zeros in the filter response. The two zeros are designed to be close to the passband, thus improving the selectivity of the filter. As an example, a four-stage cross-coupled dual-spiral filter is designed and fabricated using superconducting YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thin films deposited on LaAlO/sub 3/ substrate.     

Efficient encoding of IEEE 802.11n LDPC codes

Addressed is the issue of LDPC coding for the emerging IEEE 802.11n standard. An efficient encoding algorithm is proposed. The algorithm is simple and easy to implement. The memory requirement is trivial     

堆叠式LED结构实现紧凑型多通道光学耦合器

现代光学耦合器的核心是输入端的LED和输出端的光电探测器.它们被绝缘的光传导介质隔开.     

Copper bonded layers analysis and effects of copper surface conditions on bonding quality for three-dimensional integration

In order to achieve copper wafer bonding with good quality, surface conditions of copper films are important factors. In this work, the effects of surface conditions, such as surface roughness and oxide formation on the bond strength, were investigated under different bonding conditions. Prior to bonding, copper film surfaces were kept in the atmosphere for less than 1 min, 3 days, and 7 days, respectively, to form different thicknesses of oxide on the surface. Some copper wafers were cleaned using HCl before bonding in order to remove the surface oxide. Surface roughness of copper films with and without HCl cleaning was examined. Since surface cleaning before bonding removes oxides but creates surface roughness, it is important to study the corresponding bond strength under different bonding conditions. These results offer the required information for the process design of copper wafer bonding in three-dimensional integration applications.     

一种应用平行反馈补偿和瞬态响应增强技术的NMOS低压差电压调整器设计

本文提出了一种应用于便携式设备的,采用平行反馈补偿和瞬态响应增强技术的低压差电压调整器。平行反馈的架构引入了一个动态零点,保证环路在0A到1A的负载电流范围内具有足够的相位裕度。通过采用Class-AB结构的误差运放和快速充放电单元增强系统的瞬态响应能力。本文提出的低压差电压调整器采用0.35μm BCD工艺制造。测试结果显示,稳压器的静态电流为165μA,在1A满载情况下,压差可以达到150mV。在满负载瞬态跳变时,输出电压下掉和过冲幅度分别降低到38mV和27mV。