Radio frequency spectrum is a scarce and critical natural resource that is utilized for many services including surveillance, navigation, communication, and broadcast- ing. Recent years have seen tremendous growth in the use of spectrum especially by commercial cellular operators. Ubiquitous use of smartphones and tablets is one of the reasons behind an all-time high utilization of spectrum. As a result, cellular operators are experiencing a shortage of radio spectrum to meet bandwidth demands of users. On the other hand, spectrum measurements have shown that much spectrum not held by cellular operators is underutilized even in dense urban areas. This has motivated shared access to spectrum by secondary systems with no or minimal impact on incumbent systems. Spectrum sharing is a promising approach to solve the problem of spectrum congestion as it allows cellular operators access to more spectrum in order to satisfy the ever-growing bandwidth demands of commercial users.
标签： Spectrum Sharing Between Radars
上传时间： 2020-06-01
上传用户：shancjb
Failure analysis is invaluable in the learning process of electrostatic discharge (ESD) and electrical overstress (EOS) protection design and development [1–8]. In the failure analysis of EOS, ESD, and latchup events, there are a number of unique failure analysis processes andinformationthatcanprovidesignificantunderstandingandillumination[4].Today,thereis still no design methodology or computer-aided design (CAD) tool which will predict EOS, ESDprotectionlevels,andlatchupinasemiconductorchip;thisisoneofthesignificantreasons why failure analysis is critical to the ESD design discipline.
标签： Mechanisms Failure Models ESD and
上传时间： 2020-06-05
上传用户：shancjb
Electrostatic discharge (ESD) events can have serious detrimental effects on the manufacture and performance of microelectronic devices, the systems that contain them, and the manufacturing facilities used to produce them. Submicron device technologies, high system operating speeds, and factory automation are making ESD control programs a critical factor in the quality and reliability of ESD-sensitive products.
标签： Management Program ESD
上传时间： 2020-06-05
上传用户：shancjb
In the present era, low observability is one of the critical requirements in aerospace sector, especially related to defense. The stealth technology essentially relates to shaping and usage of radar absorbing materials (RAM) or radar absorbing struc- tures (RAS). The performance of such radar cross section (RCS) reduction tech- niques is limited by the bandwidth constraints, payload requirements, and other structural issues. Moreover, with advancement of materials science, the structure geometry no longer remains key decisive factor toward stealth.
标签： Fundamentals Design Radar of EM
上传时间： 2020-06-06
上传用户：shancjb
Electric distribution networks are critical parts of power delivery systems. In recent years, many new technologies and distributed energy resources have been inte- grated into these networks. To provide electricity at the possible lowest cost and at required quality, long-term planning is essential for these networks. In distribution planning, optimal location and size of necessary upgrades are determined to satisfy the demand and the technical requirements of the loads and to tackle uncertainties associated with load and distributed energy resources.
标签： Distribution Electric Planning Network
上传时间： 2020-06-07
上传用户：shancjb
Commercial energy storage has moved from the margins to the mainstream as it fosters flexibility in our smarter, increasingly integrated energy systems. The energy density, availability, and relatively clean fossil profile of natural gas ensure its critical role as a fuel for heating and electricity generation. As a transportation fuel, natural gas continues to increase its market penetration; much of this has been enabled by emerging developments in storage technology.
标签： Hydrogen Methane Storage Energy and for
上传时间： 2020-06-07
上传用户：shancjb
A power semiconductor module is basically a power circuit of different materials assembled together using hybrid technology, such as semiconduc- tor chip attachment, wire bonding, encapsulation, etc. The materials involved cover a wide range from insulators, conductors, and semiconduc- tors to organics and inorganics. Since these materials all behave differently under various environmental, electrical, and thermal stresses, proper selec- tion of these materials and the assembly processes are critical. In-depth knowledge of the material properties and the processing techniques is there- fore required to build a high-performance and highly reliable power module.
标签： Manufacture Electronic Modules Design Power
上传时间： 2020-06-07
上传用户：shancjb
RFID is at a critical price point that could enable its large-scale adoption. What strengths are pushing it forward? What technical challenges and privacy concerns must we still address?
标签： an-introduction-to-rfid-technolog
上传时间： 2020-06-08
上传用户：shancjb
Although doing science is at the heart of discovery, the effort would have very limited consequence in the long term without writingscience. As a social enterprise that depends on collaboration, scientific inquiry requires its practi- tioners to write on a regular basis. From time to time, some members of the scientific community have been critical of the overall quality of writing by re- searchers.
标签： Goldbort_Writing Science for
上传时间： 2020-06-09
上传用户：shancjb
Multisim官方示例Multisim仿真例程基础电路范例135例合集:Chapter 1 - RLC CircuitsChapter 2 - DiodesChapter 3 - TransistorsChapter 4 - AmplifiersChapter 5 - OpampsChapter 6 - FiltersChapter 7 - Miscellaneous CircuitsFundamental Circuits.pdf004 Parallel DC Circuits.ms10005 Series-Parrallel DC Circuit.ms10006 Current Analysis.ms10007 Millmans Theorem 1.ms10008 Millmans Theorem 2.ms10009 Kirchhoff's Current Law.ms10010 Thevenin's Theorem.ms10011 Superposition Principle.ms10012 Nortons Theorem and Source Conversion.ms10013 AC Voltage Measurement.ms10014 Frequency Response of the Series RL Network.ms10015 RL High and Low Pass Filter.ms10016 Frequency Response of the Series RC Network.ms10017 RC High and Low Pass Filter.ms10019 Center-Tapped Full-Wave Rectifier.ms10020 Bridge Rectifier.ms10021 Capacitor-Input Rectifier Filter.ms10022 Diode Clipper (Limiter).ms10023 Diode Clipper.ms10024 Diode Clamper (DC Restorer).ms10025 Diode Voltage Doubler.ms10026 Zener Diode and Voltage Regulation 1.ms10027 Zener Diode and Voltage Regulation 2.ms10028 Zener Diode and Voltage Regulation 3.ms10105 TTL Inverter.ms10107 TTL Gate.ms10109 OR Gate Circuit.ms10111 Over-Damp Circuit.ms10113 Critical-Damp Circuit.ms10115 Series RLC Circuit 1.ms10117 Clapp Oscillator.ms10119 Differential Amplifier 1.ms10121 Differential Amplifier in Common Mode.ms10123 LC Oscillator with Unity Gain Buffer.ms10125 Notch Filter.ms10127 PNP Differential Pair.ms10129 Crossover Network.ms10131 Second-Order High-Pass Chebyshev Filter.ms10133 Third-Order High-Pass Chebyshev Filter.ms10135 Fifth-Order High-Pass Filter.ms10
标签： multisim
上传时间： 2021-10-27
上传用户：trh505
