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SNF Training McGill1 _Compatibility Mode_

SNF Training McGill1 _Compatibility Mode_ - Spherical...

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Unformatted text preview: Spherical Near-field TrainingMcGill University NSI-700S-30 SNF/FF/CTIA System9 September 2009NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 1OverviewGIntroductionGBasics of antenna testing Definition of conceptsG GFar-field antenna testing Near-field antenna testingGSNF theory overviewG GHardware overview Software overview & demonstrationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 21Measurement Objective IBasic Concept:Rotate antenna under test in azimuth and elevation coordinates Record far-field data60.00 50.0040.0030.00Elevation (deg)20.0010.000.00-10.00-20.00-30.00-40.000 -2 -4 -6 -8 -10 -12 -14 -16 -18 -20 -22 -24 -26 -28 -30 -32 -34 -36 -38 -40 -42 -44 -46 -48 -50 -52 -54 -56 -58 -60-50.00NEARFIELD Azimuth (deg) Copyright 2009 NSI SYSTEMS, INC.-60.00 -60.00 -50.00 -40.00 -30.00 -20.00 -10.000.0010.0020.0030.0040.0050.0060.00Page 3Measurement Objective IIAntenna ExamplesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 42Reaction Theorem I< 1,2 >=< 2,1 >< 1,2 >= E1 J 2 - H1 M 2 dvV< 2,1 >= E2 J1 - H 2 M 1dvV1V2VNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 5Reaction Theorem II+" Measured _ Voltage" =^ z'e - 2 E J dl1 2e 2^ zl + 2^ yV-dl 2+Ve 2R^ y'- e 2NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 63Practical Restrictions & Potential SolutionsGRestrictionsG G G G G GAntenna size and weight Frequency (i.e. Positioning accuracy & RF losses) Available space Funding Security Environmental control Measurement systems suitable for antenna type Distributed conversion RF sub-systems Compact or near-field ranges Indoor instead of outdoorGPotential SolutionsG G G GNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7Distance RestrictionCommonly used rule : R >^ z'2D 2=2l 2A high gain AUT. This rule assumes:^ z+ l 2An electrically small receiver.^ yThat d=0.V-dl 2+Ve 2R^ y'- e 2NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 84Far-field CriteriaG G GSufficient antenna separation for flat phase front <22 of phase taper across aperture <0.25 dB of amplitude taper across aperturePhase front AUT Tx AntennaD 8Rx Antenna 2<22D = aperture diameter = test frequency wavelengthNSI Copyright 2009 Page 9>NEARFIELD SYSTEMS, INC.2D Far-field Separation Distance2xD**2/Lambda Far Field CriteriaSeparation Distance (m) 1000.00AUT Diameter 0.5m 1.0m 1.5m 2.0m 2.5m100.0010.001.00 1 3 5 7 9 11 13 15 17 19 Frequency (GHz)NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 105Far-field Distance EffectsNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 11FF Measurement High Gain AntennaMax & Average Error in Measured Far-fieldD = l = 5.4 d = 0, 0.1 & 0.2Error level [dB]-20 -25 40 60 80 100 120 140 160 180 20050 < R < 200 e = 0.25^ z'7D2-30 -35 -40 -45 -50 -55 -60 -65 d=0 Max d=0.1 Max d=0.2 Max^ z+ l 2-70^ yMea sured DIsta nce [m ]V-dl 2+Ve 2R^ y'NEARFIELD SYSTEMS, INC.NSI Copyright 2009e - 2Page 126FF Measurement High Gain AntennaFar-Field Radiation Patterns0 0 -10 Relative Amplitude [dB] -20 -30 -40 -50 Relative Amplitude [dB] -60 -70 -80 Theta [deg[ Ref Measured Error 0 Max 0 error 30 -10 Avg error -20 -30 -40 -50 -60 -70 -80 Theta [deg[ Ref Measured Error Max error Avg error 60 90 120 150 180 210 240 270 300 330 360 30 60 90 120 150 180 210 240 270 300 330 360R=2D 2Far-Field Radiation Patternsd = 0.1d = 0NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 13FF Measurement Low Gain AntennaMax & Average Error in M easured Far-FieldD = l = 0.45 d = 0, 0.1 & 0.2Error level [dB]0 0 -10 1 2 3 4 5 6 70.4 < R < 6 e = 0.25^ z'15D2-20 -30 -40 -50 -60 -70 d=0 Max d=0.1 Max d=0.2 Max^ z+ l 2^ yMea sured Dista nce [m]V-dl 2+Ve 2R^ y'NEARFIELD SYSTEMS, INC.NSI Copyright 2009e - 2Page 147FF Measurement Low Gain AntennaFar-Field Radiation Patterns0 -5 -10 Relative Amplitude [dB] -15 Ref -20 -25 -30 -35-10 Relative Amplitude [dB]0306090120150180210240270300330360R=Measured Error 0 Max error 0 30 -5 Avg error2D 2Far-Field Radiation Patterns120 150 180 210 240 270 300 330 3606090-40 -45 -50 Theta [deg[-15 Ref -20 -25 -30 -35 -40 -45 -50 Theta [deg[ Measured Error Max error Avg errord = 0.1d = 0NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 15Far-Field Range TypesGOutdoor Ranges G Ground reflectionNControl or characterize reflection Reduce reflectionGElevatedNGIndoor Ranges G Tapered ChamberNChamber forms part of radiation aperture control reflectionG GRectangular Chamber Compact RangesNReduce far-field distance and control reflection Reduce far-field distance using defocused feed and correctionGIntermediate Field RangesNNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 168Outdoor Far-field RangesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 17Indoor Far-Field Range Chamber: 6m x 6m x 15m Frequency range: 0.5 GHz - 40 GHz Far-field range: measurement distance: max. 7.5m Spherical near-field rangeNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 189Indoor Far-Field Range Size app. 6m x 6m x 15m Far-field range: 7.5mNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 19Far-field RangesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 2010Far-field Trade-offsAdvantagesG G G GLimitationsG G G GGLow frequency Real-time measurement results No post processing required Manual measurement capability (no automation software required) Simplified measurement setupRequires large foot print AUT must be rotated More susceptible to multi-path RF signal sensitivity may degrade measurement accuracyNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 21Fundamental Compact Range PrinciplesTransmission Compact RangesReflection Compact RangesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 2211Near-field TechnologyNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 23Measurement ObjectiveAntenna ExamplesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 2412Near-field Scan TypesGPlanar near-fieldG G GPlanarDirectional antennas Gain > 15 dBi Max angle < 70 Fan beam antennas Wide side/ backlobesCylindricalGCylindrical near-fieldG GGSpherical near-fieldG GSphericalLow gain antennas Wide or omnidirectional patterns on any antennasNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 25The Vector Wave EquationMaxwells Equations for a loss-less source free region are: H = j E E = - j HThese equations can be re-written in vector wave equation form as: 2 E = - 2 E = - k 2 E 2 H = - 2 H = - k 2 HThese second order PDF's are not coupled and a solution to them will also provide a solution to Maxwells equations. Note that the form given here is only valid for source free loss-less regions. In what follows, valid solutions for these vector wave equations are considered in rectangular, cylindrical and spherical coordinate systems. A jt time dependence is assumed.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 2613Solutions to the Vector Wave EquationIf we express the electric and magnetic fields in terms of the vector potentials we can write: A j 1 1 E= A - F j and from the derivation of these potentials, we know that they also have to satisfy the vector wave equation:H=1 F +12 F + k 2 F = 0 2 A + k 2 A = 0NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 27Solutions to the Vector Wave EquationSince the vector potentials consist of orthogonal vector components, one may also require each scalar component to satisfy the scalar wave equation as: 2 + k 2 = 0By finding solutions to this equation we can ultimately construct solutions to the vector wave equation. Since one can express any arbitrary electric field in a source free loss-less region as the sum of a transverse electric (TE) and transverse magnetic (TM) component [Harrington, p.131], we therefore select:^ z in rectangular : zA & zF ^ z in cylindrical : zA & zF ^ in spherical : r rA & r rF rNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 2814Solutions to the Vector Wave EquationRectangular CoordinatesIn rectangular coordinates a solution for the scalar wave equation is: = e - j k r^ TM : A = z ^ TE : F = zFrom which the electric field can be found:E=1 j1 ^ ^ Az z - Fz zNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 29Solutions to the Vector Wave EquationCylindrical CoordinatesIn cylindrical coordinates a solution for the scalar wave equation is: = Z ni (k ) e jn e - jk^ TM : A = z ^ TE : F = zTM part From which the electric field can be found as:zzTE partE=1 j^ ^ Az z - Fz z1NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 3015Solutions to the Vector Wave EquationCylindrical CoordinatesThe variables and functions shown on the previous slide are:i = 1, 2, 3 or 4 k = k 2 - k z21 Z n (k ) = J n (k ) = Bessel function of the first kind.2 Z n (k ) = Yn (k ) = Bessel function of the second kind. 3 1 Z n (k ) = H n (k ) = Hankel function of the first kind.4 Z n (k ) = H n2 (k ) = Hankel function of the second kind.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 31Bessel Functions INEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 3216Bessel Functions IINEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 33Hankel FunctionsCan be generated from the Bessel functions shown on the previous slides.1 H n (k ) = J n (k ) + jYn (k )2 H n (k ) = J n (k ) - jYn (k )NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 3417Solutions to the Vector Wave EquationSpherical CoordinatesIn spherical coordinates a solution for the scalar wave equation is:i = z n (kr ) Pnm (cos )e jm ^ TM : A = r r ^ TE : F = r rFrom which the electric field can be found as:E=1 j1 ^ ^ Ar r - Fr rNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 35Solutions to the Vector Wave EquationSpherical CoordinatesThe variables and functions shown on the previous slide are:0n -n m n2 z n (k ) = y n (k ) = Spherical Bessel function of the second kind.z 1 (kr ) = jn (kr ) = Spherical Bessel function of the first kind. n4 z n (k ) = hn2 (k ) = Spherical Hankel function of the second kind.3 1 z n (k ) = hn (k ) = Spherical Hankel function of the first kind.Pnm (cos ) =(1 - x )2 m/22 n n!d n+m x 2 - 1 = Legendre functions. dx n + mNSI Copyright 2009 Page 36()nNEARFIELD SYSTEMS, INC.18Spherical Bessel & Hankel FunctionsCan be generated from the Bessel & Hankel functions.jn (x ) = y n (x ) =1 hn (x ) =2xJ n +1 / 2 ( x ) Y n +1 / 2 ( x )( H n1)1 / 2 ( x ) + ) H n( 2 1 / 2 ( x ) +2x2xh n2 ( x ) =NEARFIELD SYSTEMS, INC.2xNSI Copyright 2009Page 37Legendre PolynomialsNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 3819Examples of Planar SystemsNSI Model 200V-3x3 3'x3' Vertical Planar NFNSI Model 300V-8x8 8'x8' Vertical Planar NFNSI Model 500H-22x22 22'x22' Horizontal Planar NFNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 39Toshiba 400V-108x52 (33m x 16m)GGGLargest Planar Scanner in the world. Successfully installed and validated 1-50 GHz with pulse capabilityNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 4020NSI 650 GHz mm-wave System1.0GElevation (deg)Application Microwave Limb Sounder (MLS)G G00.5-10 -20 -30GJPL Earth Observing Satellite Measurements of Earth's ozone layer and related chemistry 1.6m antenna aperture0.0-40 -50-0.5-60 -70-1.0 -1.0-0.50.00.51.0Azimuth (deg)GNSI Solution Sub-millimeter wave systemGGG2.4 m x 2.4 m precision granite scanner - 4 m rms Thermal compensation via NSI Motion Tracking Interferometry (MTI) 118 to 650 GHz operation using Agilent 8530A receiver, 104 GHz to 110 GHz Gunn oscillator and 6X frequency multiplier NEARFIELD SYSTEMS, INC.NSI Copyright 200941Spherical Near-field SystemsGNSI 700S-30 Spherical NF SystemG GGNSI 700S-70 Spherical NF System Testing X-band SGH AUT's up to 10 Kg, 1m diaTesting cellular base antenna AUT's up to 136 Kg, 2m diaNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 4221EADS UK - Spherical SystemGGGGLarge satellite production test capability Satellite on azimuth positioner with probe scanning via overhead swing arm NSI spherical data acquisition and processing software HP 8530A receiver systemNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 43Far-field TechnologyNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 4422Far-field Positioning Systems5 Axis Positioner Roll/ Slide/ Azimuth/ Elevation/ SlideNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 45Ramet Far-field Range Czech RepublicG GG GNSI Electronics and s/w upgrade Existing customer outdoor positioners ACC 9030 Positioner Controller Agilent PNANEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 4623Antenna Field BoundariesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 47Radiation Patterns IRectangular format0 -5Polar formatFar-field amplitude of 1.7-2.6 Gain Horn 4.nsi345 330 0 15 30 315 45Far-field amplitude of 1.7-2.6 Gain Horn 4.nsi-10 -15300 60-20 Amplitude (dB) -25 -30270 285 75-35 -40255-50-40-30-20-10 dB90105-45 -50 -55 -60 -150 -100 -50 0 50 Elevation (deg) 100 150240 120225135210 195 180 165150NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 4824Radiation Patterns II0Far-field amplitude of 1.7-2.6 Gain Horn 4.nsiFar-field amplitude of 1.7-2.6 Gain Horn 4.nsi345 330 0 15 30-5315 4530060-10285 75Amplitude (dB)-15270 -25 -20 -15 -10 -5 dB 90-20255105240120-25225 135210150 195 180 165-30 -150 -100 -50 0 50 Elevation (deg) 100 1500 -5Far-field amplitude of 1.7-2.6 Gain Horn 4.nsiFar-field amplitude of 1.7-2.6 Gain Horn 4.nsi345 330 0 15 30-10315 45-15300 60-20 Amplitude (dB) -25 -30270 -50 -40 -30 -20 285 75-35 -40 -45240 255-10 dB90105120-50225 135-55210 150 195 180 165-60 -150 -100 -50NEARFIELD SYSTEMS, INC.0 50 Elevation (deg)100150NSI Copyright 2009Polar format: Differing scalesPage 49Radiation Patterns III0Far-field amplitude of 1.7-2.6 Gain Horn 4.nsiMain lobeFirst side lobe-5First null-10 Amplitude (dB)-15-20-25-30 -150 -100 -50 0 50 Elevation (deg) 100 150NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 5025Radiation Patterns IV3dB Beamwidth330 315 345 0 15 30453006028575270-25-20-15-10-5 dB90255105240120225135210 195 180 165150NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 51Spherical Coordinate Systemz E Variables & are independent and orthogonal.E rE & E are orthogonal unit vectors. Variable r denotes the distance to the observer.yxNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 5226Gain & DirectivityPAvailableRadiation efficiency or lossAUT PRADPIN PReflectedDirectivity GainGDirectivity is given by,Realized GainGGain is given by,GIn practice, many people measure realized gain which is affected by VSWR and internal Ohmic losses.NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 53DirectivityDirectivity = 4 U [dBi] PradU = Radiation Intensity [W/Steradian]2 r2 U ( , ) = E ( r , , ) 2 Prad = Total radiated power [W] 2 Prad = U sin d d0 0NSI Copyright 2009 Page 54NEARFIELD SYSTEMS, INC.27GainGain = 4 U [dBi ] PinU = Radiation Intensity [W/Steradian]2 r2 U ( , ) = E ( r , , ) 2 Pin = Total input power [W] 2 Pin ecd = Prad =NEARFIELD SYSTEMS, INC. U sin d d0 0Page 55NSI Copyright 2009Efficiencyecd = AUT loss efficiency er = AUT reflection efficiency e0 = AUT total efficiency e0 = er ecd Gain = ecd Directivity er = 1 - 2 = AUT Voltage reflection coefficientNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 5628PolarizationPolarization is defined as the direction of the E-field: E-field horizontal, antenna is horizontally polarized. E-field vertical, antenna is vertically polarized. E-field rotates, antenna is circularly polarized.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 57Slant Linear PolarizationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 5829Circular Polarization INEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 59Circular Polarization IINEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 6030Polarization Ellipsey E2 Major axisOB OA x E1Minor axisNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 61Polarization NotesGG GGGIn reality LHCP and RHCP is never circular, always elliptical. LHCP and RHCP are orthogonal. Axial ratio is an indication of cross-polar isolation. CP can always be expressed as the sum of two LP components. LP can always be expressed as the sum of two CP components.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 6231RHCP Example IFar-field amplitude of RHCP Test Case.nsi - Rotating Linear Pattern & Pol Ellipse AxesG10Pol ellipse maxPol ellipse minRotating linear0-10Amplitude (dB)-20G-30Linear co- and crosspol patterns from ellipse major & minor axes and rotating linear pattern for measured RHCP antenna. Rotating linear pattern is bound by linear pol patterns.-40-50-60 -20 -15 -10 -5 0 5 Elevation (deg) 10 15 20NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 63RHCP Example IIFar-field amplitude of RHCP Test Case.nsi - Rotating Linear Pattern & Pol Ellipse AxesFar-field amplitude of RHCP Test Case.nsi - Axial Ratio20 Axial ratio NSI2000 axial ratio10Pol ellipse maxPol ellipse minRotating linear01510 -10 5 Amplitude (dB) -20 Amplitude (dB) -20 -15 -10 -5 0 5 Elevation (deg) 10 15 200-30-5-40 -10-50-15-60-20 -20 -15 -10 -5 0 5 Elevation (deg) 10 15 20Linear co- and cross-pol patterns from ellipse major & minor axes and rotating linear pattern for measured RHCP antenna - Left. Axial ratio Right.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 6432Near-field Scan TypesGGGPlanar Planar Near-field G Directional antennas G Gain > 15 dBi G Max angle < 70 Cylindrical Near-field G Fan beam antennas G Wide side/ backlobes Spherical Near-field G Low gain antennas G Wide or omni-directional patterns on any antennasCylindricalSphericalNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 65Spherical ScanningNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 6633Spherical NF Coordinate SystemNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 67Spherical System ConfigurationAUT mounting position for minimum MREMaximum Radial Extent (MRE)NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 6834Spherical Near-field Sampling CriteriaIt is found that for an AUT contained in a sphere of radius MRE, centered around the spherical coordinate system origin, the sample spacing required is:0 = 0 <k MRE=2 MRENEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 69Spherical Near-field Sampling CriteriaDistance from theta-axis to pol-stage face plate = X mm. Length of WR_xxx probe assembly = Y mm Radius = distance from probe tip to theta-axis = X Y mm. MRE = distance from theta/phi intersection to sphere enclosing AUT.AUT supportdAUTDPhi axis of rotationRadiusProbeM REAzimut axis of rotation0mNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7035Spherical TruncationTruncated Near-fieldResulting Far-fieldMeasuring less than full 360 degree spherical data can result in ripple errors in the main beam region. Recommend measuring data down to at least 30 dB from max near-field amplitudeNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 71Hardware OverviewNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7236Chamber Layout [mm]NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 73Far-Field ConfigurationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7437SNF ConfigurationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7540 67 GHz Far-Field ConfigurationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7638CTIA/OTA ConfigurationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 77Antenna Range Controller (ARC Box)GGGProvides stepper drivers for 4 axes Interfaces for AUT and probe port switches (TTL) Options:GGScanner safety system interlock Linear axis brakeNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 7839System ControllerGGSoftware G Real time motor control G Timing G Triggering G Data collection and buffering G Fault detection G Safety Hardware G I/O card (may be multiple cards) G Serial interface (communication with Windows computer) G 3.5" FDD Diagnostic and set-up functions require use of a monitor and keyboard on the system controller (2 x Scroll Lock).NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 79Software OverviewNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 8040NSI Software DescriptionG G G GIndustry Leading NSI2000 Software Runs on Windows XP & Vista (32 bit) based systems. Field Tested Daily by NSI's More than 300 Customers Worldwide Advanced scripting features: G Measurement & Processing Automation G Direct import to MS Office programs G Interface to customer-written data reduction programs and DLLs G Complete program control with macro languageNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 81NSI 2000 Software OverviewNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 8241NSI 2000 Menu OperationG G G G G GSoftware is Windows-menu based Built-in aids to help in operator test design and test set-up Fault diagnostics for common system errors with recommendations for resolution Right click options available for many menus Help pop-ups available for some fields On-line help is availableNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 83NSI 2000 Main WindowMeasurements Menu -show/hide Select Processing Menu Items Select Plot Type Script Editor - show/hide Stop ProcessAutomatically prints plots when checked Select Filename Display Beam ListNSI 2000 WindowStatus Bar - click to show/hide historyFile-read Progress BarNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 8442Typical Test ProcessG G G G G GAlign antenna Verify good RF performance Set up scan Make measurement Data processing/analysis Reports and outputNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 85Verifying RF PerformanceGStability, Linearity, Sensitivity, LeakageGNSI2000 options include:N N N NReal-time stability plot Signal-to-noise monitor Drift check MTI monitoring and correctionNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 8643Receiver Stability DisplayGSelect Measurements Stability plot0 -1 0 -2 0-3 0 Phase (deg)-4 0-5 0-6 0-7 0-8 0 0 2 0 0 4 0 0 6 00 T im e e la p se d 8 0 0 sin c e 1 0 0 0 s ta r t (m in ) 1 2 0 0 1 4 0 0 1 6 0 0NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 87Setting Up the ScanGGGGEasy scan setup. User enters: G Height and width of antenna G Probe-to-antenna separation G Maximum scan angles Auto scan setup computes: G Scan size, #pts and spacing Multi-beam G Multi-frequency, Multi-switch, Dual-pol Reference measurements G Drift check, MTINEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 8844NSI 2000 Measurement SetupOther Set-up Tabs Enter Test Title & Comments (256 characters max) Enter Monitor Frequency Real Time display of amplitude and phase Create New ScanEnter AUT Test ParametersOpen Beam Table Select Reference TypeEnter Scan Parameters (or use Auto scan Set-up)Automatically Generate Scan Set-up Start AcquisitionMeasurement TypeV or H Scan OptionsMeasurement modesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 89NSI 2000 Probe SetupSelect Probe AxisSelect Probe TypeSelect Probe Mode (OEWG, Cos model, or Pattern File) Select Probe-1 Sense (1st pol measured) Select Probe-2 Sense (2st pol measured Enter None for single pol measurement)Probe Dimensions (set automatically by choosing probe type above) CosN coefficients for matching function Az and ElNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 9045NSI2000 Multi-beam SetupFeatures such as "Use suggested dwell" and "Maximize scan speed" improve throughputNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 91NSI 2000 Beam TableInner Loop Outer LoopData taking axis Dwell Time - fixed fieldSingle Pol DataSet-up for 4 inner-loop frequenciesFrequency list is repeated for 2nd Z-positionNote: dwell times in this table apply for fast switching synthesizers, not for HP 8360-series sourcesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 9246Inner-Loop Timing DisplaysCheck to enable Amplitude and Phase columns Check for continuous Amplitude & Phase readingsExample of optimized dwell times for HP 8360 series sourcesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 93Multi-Frequency Beam TableGNSI 2000 software includes a powerful beam table generator for multi-beam and multi-frequency measurements:Easy setup& automatic dwell time optimizationUsing Agilent PNANEARFIELD SYSTEMS, INC.Beam tableContinuous real-timesave/recall & Excel compatibility NSI Copyright 2009display of amp/phase and S/N ratioPage 9447Reference MeasurementsNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 95Making MeasurementsGGGAutomatic file naming G Increments filenames: (Test.nsi becomes Test01.nsi) Measurement monitoring G Drift check, MTI (RF cable drift, pointing errors) Scan recovery G Overcoming errors during measurement without retaking the complete scanNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 9648Data Processing & AnalysisG G G GFar-field transform Probe correction Coordinate and Polarization transform Pattern analysisGPointing, 3 dB beamwidth, Sidelobes Directivity, Gain, efficiencyGGain analysisGNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 97NSI 2000 Far-field ProcessingNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 9849NSI 2000 PlotsGCartesian Polar Contour Image Surface ASCII File OutputGGGGGNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 99NSI 2000 Plots 3D VRG G G G GInteract Rotate Zoom Pan TiltNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 10050Multiple Plot OverlaysFar-field amplitude of Nrf001.dat0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50 -25 -20 -15 -10 -5 0 5 Azimuth (deg) 10 15 20 25 H-Cut V-CutFar-field H-Cut Far-field V-CutAmplitude (dB)Drag & Drop Plot OverlaysNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 101Plot Subtraction ProcessFar-field amplitude of WR28 antenna test006.nsi - Far-field amplitude of WR28 antenna test006.nsiGAmplitude (dB)GGPlot Comparisons can be made using `drag and drop' from one plot to another. This method is useful but is not able to show small differences NSI has developed a script named `plot subtraction' that is used to provide a standard way to show the differences in plots as an `error level' A low `error level' indicates a good match between the plots0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50 -55 -60-60 -50Plot 1Plot 2Plot 1 - Plot 2-40-30-20-10 0 10 Azimuth (deg)2030405060NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 10251Plot Subtraction ResultGG GRun NSI plot subtraction script Select plots to subtract Click OK to proceed-=NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 103Reporting and OutputGDocumentationGGPlot text includes the documentation of significant processing options Copy and Paste to windows program Printing, Listing to file Net-posting shows scan and script progressGData outputGGIn-process monitoringGNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 10452Listing to FileG G G G G GSelect Near-field, Far-field or Hologram display mode Click Listing Toolbar button Select File Print pull-down menu Check Print to file checkbox Enter a filename when prompted. Default file extension is .txt Listing contains data for all cuts (amplitude and phase) of the selected beam, including plot annotation.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 105Customization - ScriptingGGScripting is a macro-like language that can do anything one can do from the menus G Setting parameters, selecting options, pressing buttons Scripting uses the Basic language to give a VBA-like capability for programming and debugging G Arrays, type definition G If...then...else, Do...loop etcNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 10653Script EditorNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 107Sample ScriptNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 10854Adding Button BarsButtons invoking custom scripts can be added to the tool bar by renaming the script as follows scriptlabel.MacroX Where X= position on the tool bar Enable the button bar by selecting View Toolbars MacrobarExample: To add a button in the 3rd position called Subtract, rename the script that performs this task Subtract.Macro3Button LocationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 109Scripting User InterfaceGScripting has a built-in user-interface for simple interactionNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 11055Advanced ScriptingGActive-X interfaceGAllows calling NSI2000 from other programs like Word, Excel or Visual Basic Word documents can talk directly to NSI2000 Powerful interface capability can change the look and feel of NSI2000GActive Documents (Word and Excel)GGVisual Basic InterfaceGGhttp://www.nearfield.com/sales/Scripts.htmNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 111Visual Basic InterfaceVisual Basic Interface G Simplified NSI2000 UI via VB6 InterfaceNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 11256Advanced FunctionsG G G GData Averaging Aperture truncation and Tapering Hologram diagnostics Side lobe analysisNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 113Data AveragingGG G GSelect Beam List and click on beams to be averaged. Press and hold Ctrl and click on the beam number of the beams to perform averaging on. Beams will be highlighted in purple. Select plot type. Plot data will be an average of the selected files.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 11457Holographic ImagingGGNSI software includes ability to calculate fields at arbitrary distance from the antenna, including on the antenna aperture Holographic Imaging can be used for: G Aperture diagnostics for faulty array elements G Aperture tuning for phased array antennas G Radome system performance and diagnostics G Reflector surface error mappingNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 115Membrane AUT- Hologram FocusingHologram Backprojection during JPL Customer Test at NSI showed clear evidence of defective element in the membrane antennaNEARFIELD SYSTEMS, INC."Membrane Antenna Photo Courtesy of NASA/JPL-Caltech"NSI Copyright 2009Page 11658NSI Software Side Lobe AnalysisGGGNSI script for RMS side lobe level and null depth Works on last cut plotted Can exclude main beam region for RMS sidelobe calculationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 117Interfacing with RF EquipmentGGA wide variety of models G NSI: Panther 6000, Panther 9000 G Agilent: PNA, ENA, 8530, 8720, 8753, 8360, PSG, VXI G R&S: ZVM models, CMU200 (OTA) G Anritsu: MT8820 (OTA) A wide variety of configuration G VNA G External mixersNPNA/PSG, 8530/8360, Panther/7020NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 11859NSI2000 Limit Switches for Rotary StagesNSI Rotary stages have hardware and software limits.Software limits: Are used as "intelligent" limits for deceleration of stages. Angles can be changed by user. Reliability is dependent on axis indexing and maintaining position. Hardware limits: Are switches and are used as "hard" limits and index references. Can be bypassed in software by user. Do NOT allow for full 360 rotation without software option. Note: Any setup changes made have to be saved as default (Options/Save settings asdefault) if they are to be retained after software has been shut down.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 119Antenna MeasurementsNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 12060Scanner SafetyG GG GTurn off ARC power before approaching the scanner Don't leave tools on scanner, especially not on the precision rails! Do not step on cables Disconnecting motor cables with ARC power ON will cause damage to ARC box and/or CIO-DIO cardsNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 121Basic Near-field Acquisition Procedure1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Index scanner if necessary Install and level antenna Install and level probe, set probe distance Set up for new scan Set up parameters for AUT Set up parameters for probe (See Probe Set-up Procedure) Compute sampling parameters (Using auto scan setup) Insure probe horizontal polarization is aligned parallel to floor (Pol = 0 deg) Move scanner to scan center or reference point Verify RF signal SNR is acceptable Enter test title & comments Run scan When acquisition is completed, plot NF pattern and check for truncationNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 12261Probe Set-up Procedure1. Mount new probe to probe rotary stage or probe carriage 2. Measure probe distance to center of rotation for cylindrical & spherical NF) 3. Select the probe model 4. Select the probe type 5. Level the probe Insure probe pol stage was indexed Rotate pol stage to level Add/subtract pol position to index offset Re-index pol axis and verify pol stage returns to Co-pol positionNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 123Scanner Coordinate SystemNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 12462NSI Probe Coordinate SystemProbe setup convention.Cable.Pol = 90 degrees.yPol xyCable. xPol = 0 degrees.Facing the probe tip.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 125Common ProblemsGProbe polarization incorrectGMust set POL=0 for horizontal polarization (parallel to X axis)GWhy does amplitude display show red during acquisition?GG GSoftware normalizes to receiver amp at reference origin (usually scan center) If amp higher than 3 dB at other XY positions, will show red Data is re-normalized later, so can be ignored as long as you are sure receiver or mixer will not be saturatedNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 12663Holographic Imaging & Aperture DiagnosticsGNSI software includes ability to calculate fields at arbitrary distance from the antenna, including on the antenna aperture Holographic Imaging can be used for:G G G GGAperture diagnostics for faulty array elements Aperture tuning for phased array antennas Radome system performance and diagnostics Reflector surface error mappingNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 12732 X 32 Element X/Ku-band ArrayNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 1286432 X 32 Element X/Ku-band ArrayA minimum radius sphere of radius 44cm is required to enclose all radiating parts of the antenna (plus some margin). At a frequency of 14.5 GHz an angular sampling interval of 1.2 is required to resolve all the spherical wave expansion coefficients and these were acquired over a span of 240 and a span of 180. Based on the high directivity of the antenna, the near-field data set was truncated beyond this.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 129Principal Radiation Pattern Cuts - 14.5 GHzCo-polar cutsFar-field amplitude of 856 Prototype-02.nsi0 -5 -10 -15 -20 Amplitude (dB)Amplitude (dB)Cross-polar cutsFar-field amplitude of 856 Prototype-02.nsi0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50 -55 -60 Cross CrossCoCo-25 -30 -35 -40 -45 -50 -55 -60-30 -25 -20 -15 -10 -5 0 5 Azimuth (deg) 10 15 20 25 30-30-25-20-15-10-5 0 5 Azimuth (deg)1015202530Higher than designed cross-polar level and a directivity of 30.5 dBiNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 13065Back Projected AmplitudeX (meters)0.40X (meters)0.400.300 -10.300 -10.20-2 -3 -4 -50.20-2 -3 -4 -50.10-6Y (meters)Y (meters)Y (meters)-0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40Y (meters)-7 -8 -9 -10 -11 -12 -13 -14 -15 -160.10-6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -160.000.00-0.10-0.10-0.20-17 -18 -19 -20-0.20-17 -18 -19 -20-0.30-0.30-0.40 -0.40-0.30-0.20-0.100.000.100.200.300.40-0.40 -0.40Co-polX (meters)X (meters)Cross-polPre feed network redesign.NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 131Feed Network RedesignOriginal feed networkRedesigned feed networkNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 13266Back Projected AmplitudeX (meters)0.40 0.40X (meters)0.300 -10.300 -10.20-2 -3 -4 -50.20-2 -3 -4 -50.10-6Y (meters)Y (meters)0.10-6Y (meters)-0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40Y (meters)-7 -8 -9 -10 -11 -12 -13 -14 -15 -16-7 -8 -9 -10 -11 -12 -13 -14 -15 -160.000.00-0.10-0.10-0.20-17 -18 -19 -20-0.20-17 -18 -19 -20-0.30-0.30-0.40 -0.40-0.30-0.20-0.100.000.100.200.300.40-0.40 -0.40Co-polX (meters)X (meters)Cross-polPost feed network redesign.NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 133Antenna Gain ImprovementFar-field amplitude of 856 Prototype-02.nsi40 35 30 25 20 Amplitude (dB)Amplitude (dB)Far-field amplitude of 856 Prototype-02.nsi40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 Initial RedesignedInitialRedesigned15 10 5 0 -5 -10 -15 -20-30 -25 -20 -15 -10 -5 0 5 Azimuth (deg) 10 15 20 25 30-30-25-20-15-10-5 0 5 Elevation (deg)10152025304dB Gain improvementNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 13467Reference MaterialNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 135Far-field Angle ConventionsTHE NSI ELEVATION AND AZIMUTH ANGLE CONVENTIONSFar-field observerkx = k x = sin cos = cos E sin A = sin k ky = k y = sin sin = sin E = cos sin k kz = k z = cos = cos E cos A = cos cos kElevation = EyxAzimuth = AThese angles can be measured on a far-field range using an azimuth over elevation positionerzAntenna Spherical Coordinate Systems And Their Application In Combining Results From Different Antenna Orientations: Allen C. Newell & Greg Hindman, 1999 ESTEC Antenna Measurement Conf.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 13668Far-field Angle ConventionsTHE NSI THETA AND PHI ANGLE CONVENTIONSFar-field observerThese angles can be measured on a far-field range using a roll over azimuth positionery xzNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 137Measurement Coordinate SystemsGCoordinate System Defined by Type of 2-Axis Rotators Used (Actual or Implied) Location of Polar AxisGRoll over azimuth - fixed source = Theta/Phi, Z = Polar Roll over azimuth - rotate source = Ludwig-3, Z = Polar Azimuth over elevation = Az/EL, Y = Polar Elevation over azimuth = Alpha/Epsilon, X = PolarNot available in Spherical N-F package.GGGNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 13869Measurement Coordinate SystemsIMPORTANT CONCEPTS -GCoordinate System Is Fixed To Antenna. Sphere Rotates When Antenna Rotates Coordinate Systems Are Used To Define Both Directions And Vector-Components Direction System And Vector Component System May Be DifferentGGNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 139Measurement Coordinate SystemsYTheta/Phi coordinate system with polar axis = Z-axis, source polarization fixed during measurementCoordinate system and sphere fixed to antenna. Always rotates with antenna for all 4 coordinate systemsX ZNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 14070Measurement Coordinate SystemsYLudwig-3 coordinate system with polar axis = Z-axis, source polarization rotates during measurementv hX ZNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 141Measurement Coordinate SystemsYAzimuth over elevation coordinate system with polar axis = Y-axis. rotators at (0,0) for on-axis measurementEZAxNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 14271Measurement Coordinate SystemsYAzimuth over elevation coordinate system with polar axis = Y-axis. Rotators at (-AZ, -EL) for off-axis measurementE AZAXNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 143Measurement Coordinate SystemsYElevation over azimuth coordinate system with polar axis = X-axis. Rotators at (0,0) for on-axis measurement ZXNot available in Spherical N-F package.NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 14472Measurement Coordinate SystemsTransformation Equations between three different spherical angles and plane-wave vector components:kx , k k sin sin = sin E = cos sin = y , k k cos = cos E cos A = cos cos = z . k sin cos = cos E sin A = sin =NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 145Measurement Coordinate SystemsTransformation Equations between - and H-V (Ludwig-3) vector components:Eh ( , ) = E ( , ) cos - E ( , ) sin Ev ( , ) = E ( , ) sin + E ( , ) cosNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 14673Measurement Coordinate SystemsTransformation Equations between - and A-E (Ludwig-2) vector components:E A ( A, E ) =cos cos sin E ( , ) - E ( , ) cos E cos E cos sin cos E ( , ) + E ( , ) cos E cos EE E ( A, E ) =cos E = 1 - (sin sin ) 2NEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 147360 phi vs. 180 phi SNF ScanningAUT points to + and sides of chamberTwo different scanning geometries both give a complete AUT data setNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 14874180 phi SNF ScanningAUT points to + and sides of chamberTwo different scanning geometries both give a complete AUT data setNEARFIELD SYSTEMS, INC.NSI Copyright 2009 Page 149360 phi SNF ScanningTwo different scanning geometries both give a complete AUT data setNEARFIELD SYSTEMS, INC.AUT points to only + sides of chamberNSI Copyright 2009Page 15075Illustration of the Effect of Co-ordinate Systems When Plotting Antenna PatternsNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 151MARSGGGGMARS stands for Mathematical Absorber Reflection Suppression MARS is a post-processing algorithm to reduce the effects of scattered signals on the desired antenna pattern MARS can improve performance in a traditional chamber MARS can extend the performance of a chamber to lower frequenciesNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 15276Key MARS RequirementsG GGGGOffset AUT from center of rotation Over sampling the data in Theta and Phi helps the process Need to estimate or determine the phase center of the AUT Need to know the radius of the minimum sphere (AKA, minimum radial extent) Not required by MARS:G G GKnowledge of the AUT pattern Knowledge of the test range configuration Not frequency limitedNSI Copyright 2009 Page 153NEARFIELD SYSTEMS, INC.NSI 2000 TipsG GG G GGUse Show/Hide buttons to eliminate screen clutter Click on Status Bar to show/hide history. Can be useful in determining the cause of a problem. Sample scripts can be found in the NSI Help menu Click on the plot data label to change the field value Averaging plots can be done by selecting two or more beams in the beam table then plotting Enable FF analysis routines by setting the number of points to 1 (side lobe level, beamwidth)NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 15477NSI 2000 Number ConventionsGNumber entry:G GGSome text boxes require number entry Numbers can be entered using any combination of the following symbols : 0 1 2 3 4 5 6 7 8 9 . - e E E or e represents the exponent as in 3.2e-2 = 3.2x10-2 = 0.0032 All numbers are saved with 32 bit precision (7 digits accuracy), but are displayed to only 3 decimal places Prior to pressing the Enter key or exiting the text box, you can hit the esc key to restore the previous numberGNumerical precision:GGRestoring previous entry:GNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 155NSI 2000 Units ConventionsGUnits convention:GGGText boxes showing numbers with units, display the numbers in default units It is not necessary to enter the units when entering numbers in default units Numbers may be entered in different units, but the units must be entered along with the number in the same text box, the number will be automatically converted to default units If the units entered do not match a possible unit type, a message box will appear asking you to select from one of the unit types Select one of the possible types and continueGError handlingGGNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 15678NSI 2000 Supported UnitsGDistance units:G G G`pm', `nm', `um', `mm', `cm', `m', `meters', `km' `uin', `mil', `in', `ft', `yd', `miles', `au', `lyr' `wvlng', `lambda', `wave' `deg', `arcsec', `arcmin', `urad', `mrad', `rad' `ghz', `mhz', `khz', `hz' `sec', `ms', `us', `ns', `ps', `s', `min', `hr', `day', `yr'GPhase units:GGFrequency units:GGTime units:GNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 157NSI 2000 Real-time Key CommandsGCtrl-sG GCtrl-u Ctrl-wSaves the current state of options in the menus and dialog box to the default state These settings will be automatically restored on boot-up Toggles between English and Metric units Toggles between distance and wavelengthNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 15879NSI 2000 Saved Settings & Data FilesGSaved Settings:GThe following options can be selected from the tools menu or by pressing the indicated control key:N NCtrl-S= Saves current settings into default settings file (`Startup.srt'). Ctrl-R= Restores settings from default settings file (`Startup.srt').GData Files:G GGGNSI 2000 data files are created when data is acquired User is prompted to overwrite current data file or create new file NSI 2000 will automatically increment a numbered filename, or user can type in a new filename if desired NSI 2000 data files use .nsi extensionNEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 159Near-field Antenna Course - 2010NEARFIELD SYSTEMS, INC.NSI Copyright 2009Page 16080...
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