With the rapid growth of the wireless mobile applications, wireless voice has begun to challenge wireline voice, whereas the desire to access e-mail, surf the Web or download music (e.g., MP3) wirelessly is increasing for wireless data. While second generation (2G) cellular wireless systems, such as cdmaOne1, GSM2 and TDMA3, introduced digital technology to wireless cellular systems to deal with the increasing demand for wireless applications, there is still the need for more spectrally efficient technologies for two reasons. First, wireless voice capacity is expected to continue to grow. Second, the introduction of high-speed wireless data will require more bandwidth.
标签： Wireless Systems Mobile Beyond and 3G
上传时间： 2020-05-30
上传用户：shancjb
Since the advent of optical communications, a great technological effort has been devoted to the exploitation of the huge bandwidth of optical fibers. Start- ing from a few Mb/s single channel systems, a fast and constant technological development has led to the actual 10 Gb/s per channel dense wavelength di- vision multiplexing (DWDM) systems, with dozens of channels on a single fiber. Transmitters and receivers are now ready for 40 Gb/s, whereas hundreds of channels can be simultaneously amplified by optical amplifiers.
标签： Communication Techniques Optical Theory and
上传时间： 2020-05-31
上传用户：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.
标签： Spectrum Sharing Between Radars
上传时间： 2020-06-01
上传用户：shancjb
Recent advances in wireless communication technologies have had a transforma- tive impact on society and have directly contributed to several economic and social aspects of daily life. Increasingly, the untethered exchange of information between devices is becoming a prime requirement for further progress, which is placing an ever greater demand on wireless bandwidth. The ultra wideband (UWB) system marks a major milestone in this progress. Since 2002, when the FCC allowed the unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency band, there has been significant synergistic advance in this technology at the cir- cuits, architectural and communication systems levels. This technology allows for devices to communicate wirelessly, while coexisting with other users by ensuring that its power density is sufficiently low so that it is perceived as noise to other users.
上传时间： 2020-06-01
上传用户：shancjb
The use of optical free-space emissions to provide indoor wireless commu- nications has been studied extensively since the pioneering work of Gfeller and Bapst in 1979 [1]. These studies have been invariably interdisciplinary in- volving such far flung areas such as optics design‚ indoor propagation studies‚ electronics design‚ communications systems design among others. The focus of this text is on the design of communications systems for indoor wireless optical channels. Signalling techniques developed for wired fibre optic net- works are seldom efficient since they do not consider the bandwidth restricted nature of the wireless optical channel.
标签： Communication Wireless Optical Systems
上传时间： 2020-06-01
上传用户：shancjb
It has been said that the move from narrowband to broadband access is the second revolution for the Internet — ‘broadband is more bandwidth than you can use’. Once users have experienced broadband access there is no turning back. A whole new world of applications and services becomes possible. No longer is it the ‘world- wide wait’. The speed of response and visual quality enabled by broadband finally allows the Internet to reach its true potential.
上传时间： 2020-06-06
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
Wherever possible the overall technique used for this series will be "definition by example" withgeneric formulae included for use in other applications. To make stability analysis easy we will usemore than one tool from our toolbox with data sheet information, tricks, rules-of-thumb, SPICESimulation, and real-world testing all accelerating our design of stable operational amplifier (op amp)circuits. These tools are specifically targeted at voltage feedback op amps with unity-gain bandwidths<20 MHz, although many of the techniques are applicable to any voltage feedback op amp. 20 MHz ischosen because as we increase to higher bandwidth circuits there are other major factors in closing theloop: such as parasitic capacitances on PCBs, parasitic inductances in capacitors, parasitic inductancesand capacitances in resistors, etc. Most of the rules-of-thumb and techniques were developed not justfrom theory but from the actual building of real-world circuits with op amps <20 MHz.
标签： 运算放大器
上传时间： 2021-11-01
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Texas instruments MIPI DSI to eDP converter. Input supports 2 channel, 4 lanes each, up to 1.5GBit/s. Total input bandwidth is 12Gbit/s. Output eDP 1.4 1,2 or 4 lanes up to 5.4Gbit/s. output up to 4096x2304 60fps.
上传时间： 2021-12-22
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Precision, Low Noise, CMOS, Rail-to-Rail, Input/Output Operational Amplifiers Data Sheet AD8605/AD8606/AD8608The AD8605, AD8606, and AD86081 are single, dual, and quad rail-to-rail input and output, single-supply amplifiers. They feature very low offset voltage, low input voltage and current noise, and wide signal bandwidth. They use the Analog Devices, Inc. patented DigiTrim® trimming technique, which achieves
标签： 运算放大器
上传时间： 2022-02-02
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