全流程低功耗设计技术的应用

随着便携式电子设备的日益使用,要求集成电路IC及SoC的功耗越来越低。在今后日益复杂的设计中,实现一个可靠的电源网络以减小功耗变成了主要的挑战。对于使用者来说,期待每一代新产品都具有新型功能,同时也希望产品的体积小并具有较长的工作时间。解决这个难题的方法之一就是采用新型的IC设计技术,以提供小而且高效的晶体管。在整个设计流程中,为了使器件的性能和可靠性最优,电源方面的限制非常关键。例如在逻辑门应用中,由于开关从一种状态转换到另一种状态从而引起动态功耗。在开关的转换过程中,和晶体管门极相连的所有内部电容将会被…     

Green biomass bistable transistor multivibrator

For the first time a biomass bistable transistor multivibrator using an NPN Philips transistor as the active device and freshly plucked green Champo (Plumaria rubra) leaf cuttings as electrical components (resistance R and capacitance C) has been realized. The frequency and other parameters of the generated pulses, along with the circuit configuration, are presented. The development envisages a novel march towards a green revolution in electronic circuitry.     

Band-Notched Planar UWB Microstrip Antenna with T-Shaped Slot

Ever growing demand for higher data rates requires appropriate radiation systems with large bandwidth and stable gain. Microstrip antennas with unidirectional radiation patterns and stable gain are most useful for this purpose. A ground plane defect of microstrip patch antenna is used to breed multiband applications. As a result, the performance of gain, directivity, and bandwidth is enhanced, the geometry and shape of an ultrawideband (UWB) antenna are simplified, and its size is reduced. Thus, it results in the efficient performance with respect to wideband operation. A novel band notching of microstrip truncated UWB antenna is implemented for insusceptibility in the range 5.2–5.8 GHz. The suggested structure contains circular truncated and T-shaped slots for band notching. The optimal results can be obtained by selecting the antenna parameters. Advantages of the proposed antenna include small size, better impedance match and simple design. Details of the suggested and observational solutions are demonstrated in this paper. The S₁₁ parameter of antenna is–45.5 dB at a resonant frequency of 4.6, 5.5, and 9.8 GHz. The gain of antenna is 5.47 dB, and the value of VSWR is smaller than 2, which makes the proposed structure an ideal choice for its application in wireless communication, 5G and IoT.     

Impact of cross-phase modulation for WDM systems over positive andnegative dispersion NZ-DSF and methods for its suppression

The impact of cross-phase modulation (XPM) is measured on positive and negative dispersion fibre. The exponential build-up of XPM over positive dispersion fibre indicates amplification due to modulation instability. Methods for suppressing XPM crosstalk are also demonstrated     

QoS Recovery Schemes Based on Differentiated MPLS Services in All-Optical Transport Next Generation Internet

The Internet is evolving from best-effort service toward an integrated or differentiated service framework with quality-of-service (QoS) assurances that are required for new multimedia service applications. Given this increasing demand for high bandwidth Internet with QoS assurances in the coming years, an IP/MPLS-based control plane combined with a wavelength-routed dense wavelength division multiplexing (DWDM) optical network is seen as a very promising approach for the realization of future re-configurable transport networks. Fault and attack survivability issues concerning physical security in a DWDM all-optical transport network (AOTN) require a new approach taking into consideration AOTN physical characteristics. Furthermore, unlike in electronic networks that regenerate signals at every node, attack detection and isolation schemes may not have access to the overhead bits used to transport supervisory information between regenerators or switching sites to perform their functions. This paper presents an analysis of attack and protection problems in an AOTN. Considering this, we propose a framework for QoS guarantees based on the differentiated MPLS service (DMS) model and QoS recovery schemes against QoS degradation caused by devices failures or attack-induced faults in an AOTN. We also suggest how to integrate our attack management model into the NISTs simulator—modeling, evaluation and research of lightwave networks (MERLiN).     

用广播与选择型OADM实现低成本透明光传输

互联网业务和数据业务的不断增长，使长途骨干网中的业务传送模式发生了显著变化。目前，互联网业务流比传统的话音业务流的传送距离远得多。研究表明，从2000年到2005年，北美地区的互联网业务流的平均传输距离将从目前的740公里增长到2700公里。业务传送模式的根本性变化，要求网络设计与运营模式也作相应的更新。今后，网络节点必须能提供更多的带宽和更长的电路连接。如果采用不透明的光网络，所有的信号都必须在每个中间节点进行再生，对于60%的传输距离不超过600公里的话音业务而言是不成问题的；但对于60%的传输距离超过3000公里的互…     

Flexure control using piezostack actuators: design and implementation

In this paper, the application of high control authority piezostack actuators (PSAs) for active vibration control of large-scale flexible structures is studied. The idea is to add PSAs at appropriate locations of a flexible structure in order to strengthen its stiffness characteristics. In this regard, a flexible link of a macro-micro manipulator system actuated with PSAs is considered. The design of a mechanism for converting the force produced by a PSA to a bending moment is presented and a model for a system consisting of a flexible beam and a PSA is obtained. To this end, the solution of the governing partial differential equation with nonhomogeneous boundary conditions is obtained. Using singular value decomposition of the controllability Grammian of the system, optimum values for actuator parameters are obtained. The experimental results confirm that the suggested method can open up new possibilities in active vibration control of large-scale structures that require a large amount of control authority.