简介:Theneedforwide-bandclockanddatarecovery(CDR)circuitsisdiscussed.A2Gbpsto12Gbpscontinuous-rateCDRcircuitemployingamulti-modevoltage-controloscillator(VCO),afrequencydetector,andaphasedetector(FD&PD)isdescribed.Anewautomaticfrequencybandselection(FBS)withoutexternalreferenceclockisproposedtoselecttheappropriatemodeandalsosolvetheinstabilityproblemwhenthecircuitispoweringon.Themulti-modeVCOandFD/PDcircuitswhichcanoperateatfull-rateandhalf-ratemodesfacilitateCDRwithsixoperationmodes.TheproposedCDRstructurehasbeenmodeledwithMATLABandthesimulatedresultsvalidateitsfeasibility.
简介:Thisletterpresentsalowcostsolutionforwavelengthdivisionmultiplexedorthogonalfrequencydivisionmultiplexedpassiveopticalnetwork(WDM-OFDM-PON)withwidelytunableopticalfilterandlinearsmallform-factorpluggable(SFP)module.With9-nmtunablerangefrom1551to1560nm,thetunablefiltercansupportupto10-channel100-GHzspacingWDMPONsystem.Alinearavalanchephotodiode(APD)basedSFP+moduleisdesignedforopticalOFDMsignaldemodulation,whichcanprovidebetterreceiverperformancecomparedwithlimitingAPDmodule.Experimentalresultsshowthat~34dBpowerbudgetcanbeachievedin4×5-GbpsWDM-OFDM-PONsystem,whichcansatisfythetransmissionrequirementsofnextgenerationPONsystem.
简介:目前,据日本《东洋经济》预测,今后10年将取得飞跃性发展的10大技术是:1.便携式信息机器2.燃料电池汽车3.使用电脑的高科技农业4.上网定购高品质、低价位商品5.步入虚拟生活时代
简介:上期讲到,小雄他们穿过暗道来到了一个大厅,大厅里的景象让众人目瞪口呆!这时,一向不讨人喜欢的西单不知被什么东西叮了一下,便神色恍惚地离开了众人……