One of the prerequisites for the development of telecommunication services is the understanding of the propagation of the waves, either acoustic, electromagnetic, radio or light waves, which are used for the transmission of information. In this work, we shall limit ourselves to the study of radio waves: this term apply to the electromagnetic waves used in radio communications. Their frequency spectrum is very broad, and is divided into the following frequency bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves (300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub- EHF waves (300-3000 GHz).
標(biāo)簽： Propagation Radio Wave
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Reliable and accurate positioning and navigation is critical for a diverse set of emerging applications calling for advanced signal-processing techniques. This book provides an overview of some of the most recent research results in the field of signal processing for positioning and navigation, addressing many challenging open problems.
標(biāo)簽： Positioning Terrestrial Satellite Radio and
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
In this thesis several asp ects of space-time pro cessing and equalization for wire- less communications are treated. We discuss several di?erent metho ds of improv- ing estimates of space-time channels, such as temp oral parametrization, spatial parametrization, reduced rank channel estimation, b o otstrap channel estimation, and joint estimation of an FIR channel and an AR noise mo del. In wireless commu- nication the signal is often sub ject to intersymb ol interference as well as interfer- ence from other users.
標(biāo)簽： Communications Space-Time Processing Wireless for
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
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.
標(biāo)簽： Spectrum Sharing Between Radars
上傳時(shí)間： 2020-06-01
上傳用戶：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.
標(biāo)簽： Mechanisms Failure Models ESD and
上傳時(shí)間： 2020-06-05
上傳用戶：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.
標(biāo)簽： Management Program ESD
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
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.
標(biāo)簽： Fundamentals Design Radar of EM
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
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.
標(biāo)簽： Hydrogen Methane Storage Energy and for
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
蟲蟲下載站版權(quán)所有 京ICP備2021023401號(hào)-1
