ACSP · Analog Circuits and Signal Processing Olivier Jamin Broadband Direct RF Digitization Receivers ANALOG CIRCUITS AND SIGNAL PROCESSING Series Editors Mohammed Ismail, The Ohio State University Mohamad Sawan, E´cole Polytechnique de Montre´al For furthervolumes: http://www.springer.com/series/7381 Olivier Jamin Broadband Direct RF Digitization Receivers OlivierJamin NXPSemiconductors CampusEffiscience,2EsplanadeAntonPhilips BP20000,14906Caencedex9,France [email protected] ISBN978-3-319-01149-3 ISBN978-3-319-01150-9(eBook) DOI10.1007/978-3-319-01150-9 SpringerChamHeidelbergNewYorkDordrechtLondon LibraryofCongressControlNumber:2013944572 ©SpringerInternationalPublishingSwitzerland2014 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpart of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionor informationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilar methodologynowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerpts inconnectionwithreviewsorscholarlyanalysisormaterialsuppliedspecificallyforthepurposeofbeing enteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthework.Duplication ofthispublicationorpartsthereofispermittedonlyundertheprovisionsoftheCopyrightLawofthe Publisher’s location, in its current version, and permission for use must always be obtained from Springer.PermissionsforusemaybeobtainedthroughRightsLinkattheCopyrightClearanceCenter. 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Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) A Ce´line, Louis, Martin et Fe´lix Preface Context Digital communications have evolved to meet the demand of consumers for increasingaccesstoInternetbrowsing,TV, VideoonDemand,interactivegames, andsocialnetworking.Thisdatarateincreaseisachievedbyusingadvancedsignal processing techniques, more complex modulations, and wider signal bandwidths. Therefore,high-performancereceivers,abletocapturewide-bandwidthsignals,are requiredforhigh-endconsumercommunicationandinfrastructureequipments.For instance, this includes Cable and Satellite home gateways, cellular infrastructure transceivers,andwhite-spacespectrumsensing. As signal bandwidth continuously increases in these applications, the usage of narrowbandreceiversmightnotbecomepowerefficient.Inaddition,costpressure requestslow-costmultichannelreceiverstobemorecost-effectivethanamultitude of narrowband receivers. Figure 1 shows a typical satellite receiver: an outdoor unit translatesthe satellitebandfrom the 10GHz range to950 MHz–2,150 MHz. Asseveral36MHz-widechannelsarerequiredtobereceivedinordertoallowthe user to perform simultaneously HD video watching or recording, a wideband receiver capturing the full 950 MHz–2,150 MHz band could replace several 36MHz-BWRFreceivers. Indefense,radio-astronomy,spacetelecomapplicationswhichrequiremultiple receivers, advances in CMOS processes could open the door to complex signal processing implementation. The use of these techniques is typically not viable in widebandapplications,sincetheuseofparallelstate-of-the-artwidebandreceivers would not be power and size/weight competitive. For instance, in S-band/L-band digital communication and radars applications, the versatility and performance advantagesthatdigitalbeamforming(Fig.2,right)couldbring,comparedtoanalog beamforming(Fig.2,left),arenotpossibleduetothelackoflow-powerlow-size widebandreceivers. vii viii Preface Outdoor Unit M RF receivers ... U ... Indoor CPE X RF= DVB-S / S2 symbol demod 11.7GHz- 12.75GHz DVB-S / S2 symbol demod Video ... IF= processing (MPEG) 950MHz- DVB-S / S2 2150MHz symbol demod DVB-S / S2 symbol demod Fig.1 Satellitebroadbandmultichannelreception A A A A A A A A D D D D D D D D A Digital Summation D Fig.2 Left:Analogbeamforming.Right:Digitalbeamforming Identified Research Objectives Theresearchofhighlyintegratedreceivers,intheDC-3GHzrange,andcapturing signal bandwidths of few hundreds of MHz are targeted in this work. Direct RF digitization receivers are attractive for these wideband applications, but several stepshavetobetakenintoaccountinordertoprovideperformingsolutions. Theidentifiedresearchactivitiesthatarerequiredtotacklethesechallengesare asfollows: (cid:129) Architect direct RF digitization receivers at system level from RF to DSP, considering broadband aspects, and trades-off between cost, power consump- tion,RFperformance,andsize. (cid:129) Designhigh-performancelow-powerADCsinaCMOStechnology. (cid:129) Designlow-powerhigh-speedDigitalChannelSelection. (cid:129) DesignadequateRFsignalconditioningthatrelaxestheADCrequirements. (cid:129) ProvethefullsystemperformancefromRFtobasebandprocessing. Preface ix Author Contributions and Book Organization Thisworkpresentsthesystem-leveldesignofdirectRFdigitizationreceivers,from theorytorealizationandmeasurementsforacablemultichannelreceiver. Themaincontributionsofthisbookareasfollows: (cid:129) System-levelanalysisanddesignofdirectRFdigitizationreceivers (cid:129) Theoretical analysis of broadband nonlinear distortion for low-pass and band- passsamplingschemes (cid:129) Theoretical analysis of sampling and quantization (clock purity, time- interleavederrors,signal-dependentnoise)inabroadbandreceptioncontext (cid:129) Designofanapplication-optimizedsignalconditioner,including: – A single-inductance multi-slope programmable RF amplitude equalizer, togetherwithitscontrolalgorithm – Amixed-signalAGCloopcombiningRMSandpeakdetection (cid:129) DesignofanintegrateddirectRFdigitizationproduct,exceedingstate-of-the-art powerconsumption,cost(siliconarea),andequivalentorbetterRFperformance thanlegacysilicontuners Thisbookisorganizedasfollows: In Chap. 1, signal processing techniques are reviewed, from RF mixing through sampling to analog-to-digital conversion. The state of the art of radio receivers is provided,motivatingthefocusondirectRFdigitizationarchitecture. Thesystem-leveldesignframeworkfordirectRFdigitizationreceiversisprovided in Chap. 2, linking the communication system specifications to the receiver impairments, with a special focus on the broadband aspects of sampling and digitization, including broadband nonlinear distortion, ADC time-interleaving nonidealities,andclockpurity. InChap.3,thetheorydevelopedinChap.2isappliedtothesystem-leveldesignof a direct RF digitization receiver product for multichannel cable. An optimum RF signalconditioningisinvestigated. Chapter 4 presents the block-level design of the RF signal conditioner and the mixed-signal front end and also presents the system-level measurement results of thereceiverinabroadbandenvironment. Finally,ageneralconclusionrecapitulatesthepresentedworkandintroducesfuture workorientationsandperspectives.