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Agilent4287A RF LCR Meter1 MHz - 3 GHzTechnical Overview

High-Speed RF LCR Meter Anticipating Next Generation Test NeedsThe Agilent 4287A is a high performance RF LCR meter best fit to production line testing of devices such asSMD inductors and EMI filters, where impedance testing at high frequencies is required.Signal-level monitor functionMonitors the test signal voltageor current applied to the deviceunder test.8.4 inch color LCD displaySelectable measurementparameters (4 parameters canbe displayed simultaneously)Small test head with 1m test cableExtension to an automatedcomponent handler withoutintroducing additional errorLAN interface For remote test controland fast data transferRdc (DC resistance)measurement functionFor contact checkNavigation keys and rotary knobSupport front panel operationwithout the mouse3.5 mm (female) test portExternal VGA output Display measurement resultson a larger VGA monitorOpto-isolated handler interface Easy integration with an automaticcomponent handler Highest throughput in automaticcomponent test handshakingExternal keyboard and mouse interface Easy to use by simplifyingmeasurement setup and programming2GPIB interface Controlled by external PC.(cannot control external devices)

The 4287A greatly increasesmanufacturing testing efficiencywith fast measurement speeds(9 msec/point) and a statisticalanalysis function, among the otherpowerful functions, such as thebuilt-in comparator function. Inaddition, the 4287A improves uponthe measurement accuracy andimpedance measurement rangeof previous RF LCR meters. Theseimprovements are realized byadvanced techniques in analogcircuit design. The 4287A achievesbetter measurement repeatabilityand stability, even at the lowtest-signal levels required forSMD inductor testing.Setup display select menuSetup editorChanges can be made easilywith the mouse or navigation keysUser-friendly interfaceAn object-oriented user interfacethat is navigable using the mouse,panel keys or keyboard simplifiescomplicated measurement setupprocedures. Setups, including testfrequency, signal level (also whenusing list-sweep), and limits for themulti-function comparator, can beperformed and verified easily byediting the setup-tables. The setupeditor has eight page tables andcan store eight different setups.After the setup tables have beenestablished, the active measurementsetup can be chosen simply byselecting the corresponding number(1 through 8).8 page setup tablesFigure 1. List sweep setup displayKey specificationsTest frequency1 MHz - 3 GHz with 100 kHz resolution.With list-sweep, up to 32 points per sweep is available.Impedance parameters Z , θz (rad), θz (deg), Y , θy (rad), θy (deg), X, G, B, Ls, Lp, Cs, Cp, Rs, Rp, Q, DDisplay resolutions5 digitsTest signal levelV (open condition): 4.47 mVrms - 502 mVrms (447 mVrms when 1 GHz)I (short condition): 0.0894 mArms - 10 mArms (8.94 mArms when 1 GHz)Basic accuracy 1.0%Measurement range200 mΩ to 3 kΩ (@1 MHz, accuracy 10%)Measurement time9 msec per point (max. speed)Measurement terminal3.5 mm (female)Calibration and compensationOpen/short/load/low-loss capacitor calibration, fixture electrical lengthcompensation, open/short compensationRdc measurement functionFor contact check (on/off selectable)Data storage devicesAbout 18 Gbyte internal hard disk and 1.44 Mbyte floppy diskInterfaceGPIB, LAN (10base-T/100base-TX automatically switched), andOpto-isolated handler interface3

Improving Throughputand Quality In ProductionLine TestingAccurate impedancemeasurement using theRF I-V measurement methodThe 4287A uses the RF I-Vmeasurement method for measuringimpedance by measuring the currentflowing through a device under test(DUT) and the voltage applied acrossthe DUT. These measurements ofcurrent and voltage can be made overthe entire measurement frequencyrange (to 3 GHz). RF I-V enablesaccurate measurement over a wideimpedance range. The impedancemeasurement range is much widerthan that of network analyzers.For a very small inductance, onthe order of a few nH, this is abig advantage.Figure 2. Accurate multiple frequency impedance measurementsStable measurements at lowsignal levels with high speedSMD inductors require testingwith test currents on the order of100 micro-amps. It is difficult tomaintain high test-throughput withprevious RF LCR meters, sincemany sequential measurements arerequired when averaging to reducemeasurement variation.Measurement stability at low-testsignal levels is improved with the4287A making highly repeatablemeasurements possible. The 4287Acan increase test throughput due tothe decrease of the averaging factor.Contact check using the Rdcmeasurement functionContact failure between a DUT andthe measurement plane of an automatic component handler is a factorfor bin sorting error in productionline testing. Contact check using thebuilt-in DC resistance measurementfunction improves the accuracy andefficiency of bin 50.30.35[nH]Figure 3. Stability comparison at low signal level00.511.522.533.544.5DUT: 10 nH (Q 10.6)Conditions:100 MHz, 200 µA, AVG 13 Sigma when 100 times measurements

Accurate automated testing byadvanced calibrationIt is very important to eliminatecomplicated error elements causedfrom the use of test fixtures andcables that extend the test head ofthe 4287A. This is especially truefor measurements that use anautomated component handler.Accurate measurements, whichcorrelate well with results obtainedfrom manual testing, can be achievedat the measurement plane of a testfixture by performing open/short/loadcalibration with a “working” loadstandard.In other words, open/short/loadcalibration, at the measurementplane is dependent solely on thevalue assigned to the “workingstandard” by manual testing ofthat component. Since differentcalibration standard referencevalues can independently be set ateach list sweep frequency, multifrequency measurements can bemade accurately with this reliablecalibration functionDifferent calibration referencevalues can independently beset at each list sweep frequencyFigure 4. Calibration standard data setup displaySTARTMeets conditions#1 to #4 of BIN1?YESNOMeets conditions#1 to #4 of BIN2?Multi-function comparatorThe 4287A is equipped with amulti-function comparator to meeta wide variety of testing needs.The comparator setup display isformatted as a table. Each rowrepresents a bin number, and eachcolumn represents the sortingconditions for each bin. When allsorting conditions set for a bin aresatisfied, the judgement result issorted to the bin. There are thirteenbins, with four limit values for eachbin. Conditions such as frequencyand measurement parameters canbe set independently in each column,enabling the 4287A to meet varioussorting needs, including differentparameters at different measurementfrequencies.Sorts to BIN1Sorts to BIN2YESNOMeets conditions#1 to #4 of BIN13?Sorts to BIN13YESNOSorts to OUT OF BINSFigure 5. Bin-sort sequenceFigure 6. Comparator setup display5

Statistical functionsData storageThe 4287A is equipped with functionsto statistically analyze data. Thesefunctions improve the efficiency ofthe data acquisition required inquality control.The 4287A built-in data storageincludes a 3.5 inch floppy disk driveas well as a hard disk drive. Thesepowerful storage devices permitsave and recall of measurementsetup parameters (instrument state)and measurement data. In addition,measurement setup parametersand data can be transferred betweenthe 4287A and an external computervia the GPIB or LAN interface.The statistical analysis functioncalculates the following statisticalparameters for as many as 240000measurement points. Originalmeasurement results for the statisticalanalysis function can be obtainedvia LAN interface. Examples of normal data(non-failure)Cumulative normal samples, mean,maximum, minimum, standarddeviation, and 3 σ/mean Examples of failure analysisCumulative failure samples,cumulative Rdc failures, cumulativeoverload samples Total number of normal/failuredataInterfacing with an automatedcomponent handlerThe measurement plane can beextended from the front panel ofthe instrument to the measurementstage with the 1 m test cable and thesmall size test head. Note that themeasurement accuracy is specified atthe test head. It is possible to extendthe test cable an additional meterwith a 1 m extension cable. Inaddition, connection to an externalcomputer or an automated componenthandler can be accomplished via theGPIB interface and the opto-isolatedhandler interface. The LAN interfaceenables network communication,and greatly empowers massive datatransfer to a remote computer.PCLANGPIBHandlerHandler I/F3.5 mmSmall test head4287A1 m cable( 2 m max. (Option 4287A-020))Figure 7. Handler system example with the 4287A6

Research and Developmentof Next Generation Devicesand Improving ReliableQuality ControlThe accurate impedance measurementcapability of the 4287A with thevarious kinds of test accessoriesoffers you total measurementsolutions for the areas of researchand development, as well as qualitycontrol.Accurate impedance evaluationup to 3 GHzCharacterization of components atoperating frequencies in excess of2 GHz is becoming common due tothe development and evaluationof RF SMD inductors used inwireless communication equipment.The 4287A employs the RF I-Vmeasurement method of measuringimpedance by measuring the currentflowing through a device undertest (DUT) and the voltage appliedacross the DUT. The 4287A enablesaccurate measurement over animpedance range much wider thanthat of network analyzers (reflectioncoefficient method).Total measurement solutionWhen electronic components areevaluated, the test accessories shouldbe suitable for their shape and sizefor accurate impedance measurements.Agilent offers various kinds of 7-mmtest fixtures, which are compatiblewith the 4287A. You can select theappropriate one for your device'ssize, shape, and application. The16196A, B, C and D SMD test fixtures,developed with a coaxial structure,make RF impedance measurementsto 3 GHz possible. The 16196A, B, Cand D correspond to the chip sizes,1608 (mm)/0603 (inch), 1005 (mm)/0402 (inch), 0603 (mm)/0201 (inch),and 0402 (mm)/01005 (inch)*respectively.The repeatable DUT positioningcapability and reliable contactsenable stable measurement results,and reduce the possibility of operatorinduced error. Evaluation of SMDinductors to 3 GHz, which has beendifficult to implement so far, caneasily be performed with goodrepeatability by using the 4287Awith the 16196A/B/C/D test fixtures.When the 16200B is used with the4287A, a 7 mm test fixture, and anexternal dc bias source, dc biascurrent can be applied to devicessuch as the EMI filter (up to 1 GHz).CapUpper electrodeDUTInsulatorOuter connectorLower electrode7 mm connectorFigure 8. Cross-sectional drawing of 16196A/B/C*EIAJ/EIA chip size codeFigure 9. Total measurement solution example (with 16196A)7