Changes in telecommunications are impacting all types of user group, which include business users, traveling users, small and home offices, and residential users. The acceptance rate of telecom- munications and information services is accelerating significantly. Voice services needed approximately 50 years to reach a very high teledensity; television needed just 15 years to change the culture and lives of many families; the Internet and its related services have been penetrating and changing business practices and private com- munications over the last 2 to 3 years.
標(biāo)簽： Telecommunications Handbook The
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
The continuing explosive growth in mobile communication is demanding more spectrally efficient radio access technologies than the prevalent second generation (2G) systems such as GSM to handle just the voice traffic. We are already witnessing high levels of mobile penetration exceeding 70% in some countries. It is anticipated that by 2010 more than half of all communications will be carried out by mobile cellular networks. On the other hand, the information revolution and changing life habits are bringing the requirement of commu- nicating on a multimedia level to the mobile environment. But the data handling capabilities and flexibility of the 2G cellular systems are limited.
標(biāo)簽： Planning Network UMTS
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
An acronym for Multiple-In, Multiple-Out, MIMO communication sends the same data as several signals simultaneously through multiple antennas, while still utilizing a single radio channel. This is a form of antenna diversity, which uses multiple antennas to improve signal quality and strength of an RF link. The data is split into multiple data streams at the transmission point and recombined on the receive side by another MIMO radio configured with the same number of antennas. The receiver is designed to take into account the slight time difference between receptions of each signal, any additional noise or interference, and even lost signals.
標(biāo)簽： Understanding_the_Basics_of_MIMO
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
In the seven years since the first edition of this book was completed, Electrostatic Discharge (ESD) phenomena in integrated circuits (IC) continues to be important as technologies shrink and the speed and size of the chips increases. The phenom- ena related to ESD events in semiconductor devices take place outside the realm of normal device operation. Hence, the physics governing this behavior are not typ- ically found in general textbooks on semiconductors.
標(biāo)簽： Integrated Circuits Silicon ESD In
上傳時(shí)間： 2020-06-05
上傳用戶：shancjb
ESD is a crucial factor for integrated circuits and influences their quality and reliability. Today increasingly sensitive processes with deep sub micron structures are developed. The integration of more and more functionality on a single chip and saving of chip area is required. Integrated circuits become more susceptible to ESD/EOS related damages. However, the requirements on ESD robustness especially for automotive applications are increasing. ESD failures are very often the reason for redesigns. Much research has been conducted by semiconductor manufacturers on ESD robust design.
標(biāo)簽： Guidelines Design Basic ESD
上傳時(shí)間： 2020-06-05
上傳用戶：shancjb
The planarization technology of Chemical-Mechanical-Polishing (CMP), used for the manufacturing of multi- level metal interconnects for high-density Integrated Circuits (IC), is also readily adaptable as an enabling technology in MicroElectroMechanical Systems (MEMS) fabrication, particularly polysilicon surface micromachining. CMP not only eases the design and manufacturability of MEMS devices by eliminating several photolithographic and film issues generated by severe topography, but also enables far greater flexibility with process complexity and associated designs. T
標(biāo)簽： mechanical polishing Chemical
上傳時(shí)間： 2020-06-06
上傳用戶：shancjb
Thanks to the advances in micromachining fabrication technologies and significant cost reduction due to mass production, miniature sensors of angular rate, or gyroscopes, found their way into the everyday life of every user of modern gadgets, such as smart phones, tablets or even wristwatches. Often without realising, many of us are carrying in our pockets fully equipped with all necessary sensors complete inertial navigation systems that not so long ago were available only for advanced vehicles in sea, land, air or space. Accelerometers and gyroscopes are found in specifications of any gadget supposed to react to user movements. And one of the most commonly used type of gyroscopes used to developed these systems is Coriolis vibratory gyroscope (CVG).
標(biāo)簽： Gyroscopes Vibratory Coriolis
上傳時(shí)間： 2020-06-06
上傳用戶：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.
標(biāo)簽： Distribution Electric Planning Network
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
The first edition as well as its forerunner of Kuffel and Abdullah published in 1970 and their translations into Japanese and Chinese languages have enjoyed wide international acceptance as basic textbooks in teaching senior under- graduate and postgraduate courses in High-Voltage Engineering. Both texts have also been extensively used by practising engineers engaged in the design and operation of high-voltage equipment. Over the years the authors have received numerous comments from the text’s users with helpful suggestions for improvements. These have been incorporated in the present edition. Major revisions and expansion of several chapters have been made to update the continued progress and developments in high-voltage engineering over the past two decades.
標(biāo)簽： Engineering Voltage High
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
The use of renewable energy systems, such as wind power, hydropower, tidal power, solar power, geothermal power and biomass burn is growing. Research in electric power generation from renewable sources is continuously expanding and stands for an area of high technological and financial importance. The implemen- tation of new technologies for the functioning and management of renewable energy systems will help to further develop the renewable energy sector.
標(biāo)簽： Intelligent Renewable Systems Energy
上傳時(shí)間： 2020-06-07
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