Ultra-wideband (UWB) technology enables high data-rate short-range communica-
tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds,
over a wide spectrum of frequencies, while keeping power consumption at low lev-
els. This low power operation results in a less-interfering co-existence with other
existed communication technologies (e.g., UNII bands).
In addition to carrying a huge amount of data over a distance of up to 230 feet
at very low power (less than 0.5mW), the UWB signal has the ability to penetrate
through the doors and other obstacles that tend to reflect signals at more limited
bandwidths and higher power densities.
The first practical examples of mobile communications were used in many countries like
the USA, the UK and Germany in military services, and played a significant role in the
First World War to transfer important information from the front to headquarters to take
further actions. Good and secure wireless communications were an important need for all
military services – army, navy and air force. In this respect, the Second World War was a big
experimental battlefield for the development and evolution of mobile radio. It was in the
interests of governments that after the Second World War the military investment should
be paid back by civilian use, and all western European countries started their so-called first
generation of mobile communication networks.
Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility
andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea
phone call, or sitting in front of a personal computer to send an e-mail or download a video
program, has become an old story. Nowadays it is commonplace for people to talk over a cell
phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain.
Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications
over three generations, with the fourth generation being under way.
Over many years, RF-MEMS have been a hot topic in research at the technology
and device level. In particular, various kinds of mechanical Si-MEMS resonators
and piezoelectric BAW (bulk acoustic wave) resonators have been developed. The
BAW technology has made its way to commercial products for passive RF filters,
in particular for duplexers in RF transceiver front ends for cellular communica-
tions. Beyond their use in filters, micromachined resonators can also be used in
conjunction with active devices in innovative circuits and architectures.
The PW2606B is a front-end over voltage and over current protection device. It achieves wide inputvoltage range from 2.5VDC to 40VDC. The over voltage threshold can be programmed externally orset to internal default setting. The low resistance of integrated power path nFET switch ensures betterperformance for battery charging system applications. It can deliver up to 1A current to satisfy thebattery supply system. It integrates the over-temperature protection shutdown and auto-recoverycircuit with hysteresis to protect against over current events
The PW2601 is a charger front-end integrated circuit designed to provide protection to Li-ionbatteries from failures of charging circuitry. The device monitors the input voltage, battery voltageand the charging current to make sure all three parameters are operated in normal range. Thedevice will switch off internal MOSFET to disconnect IN to OUT to protect load when any of inputvoltage, output current exceeds the threshold. The Over temperature protection (OTP) functionmonitors chip temperature to protect the device. The PW2601 also can protect the system’sbattery from being over charged by monitors the battery voltage continuously. The deviceoperates like a linear regulator, maintaining a 5.1V output with input voltages up to the input overvoltage threshold.The PW2601 is available in DFN-2x2-8L package. Standard products are Pb-free and Halogenfree
為了提高超高頻RFID系統(tǒng)中閱讀器在低信噪比的情況下仍具有較高的識別能力,提出一種基于FPGA系統(tǒng)結(jié)合軟件無線電方法實(shí)現(xiàn)超高頻RFID射頻前端電路方案。超高頻射頻識別系統(tǒng)必須符合EPC Class 1generation 2標(biāo)準(zhǔn),所設(shè)計(jì)的電路系統(tǒng)以Xilinx公司的XC6SLX16-2CSG324FPGA芯片為硬件基礎(chǔ),將數(shù)字基帶調(diào)制解調(diào)和中頻濾波電路在FPGA系統(tǒng)中設(shè)計(jì)實(shí)現(xiàn),重點(diǎn)闡述了射頻前端電路的設(shè)計(jì)結(jié)構(gòu)、AD/DA轉(zhuǎn)換電路,以及數(shù)字濾波器的設(shè)計(jì)。實(shí)驗(yàn)結(jié)果表明,所設(shè)計(jì)的超高頻RFID閱讀器簡化了前端電路系統(tǒng)結(jié)構(gòu),提升了穩(wěn)定性,增強(qiáng)了抗干擾能力。該電路系統(tǒng)在信噪比較低的情況下,能夠較好地實(shí)現(xiàn)915MHz頻率的射頻接收和發(fā)送。In order to improve the reader UHF RFID system still has a higher ability to identify,in the case of low signal-to-noise ratio.The UHF RFID systems must comply with EPC Class 1 generation 2 standard.In this paper,the design of the circuit system based on Xilinx＇s XC6SLX16-2CSG324 FPGA chip,and presents UHF RFID RF front-end circuit with software radio based on FPGA system.Digital baseband modem and IF filter circuit is designed and implemented in the FPGA system,and focused on designing the structure of the RF front-end circuit,AD/DA conversion circuits,and digital filter.Experimental results show that the UHF RFID reader de...
VITA 46 Highlights Retain standard 6U and 3U form-factors Height, depth, pitch, front panel arrangements, conduction-cooled interfaces, etc.Support standard-length PMC and XMC modules· Support high-speed serial fabric on the backplane Tyco MultiGig RT2,7-row connector· Support VME and PCI interfaces for legacy compatibility· Provision for optical connectors as option· Support improved logistics Provide support for Line Replaceable Module(LRM) applications with ESD-protected connector Alignment and keying blocks
