2Time Table 1:30 – 2:00 Greeting 2:00 – 3:50 Technical Seminar Part I 3:50 – 4:10 Coffee Break4:10 – 6:00 Technical Seminar Part II
3This one day course contains Antenna definitionAntenna parametersDifferent antenna typesgigaAnt standard antennasPCB issuesOther factors that influence the antennaMatching and tuningTesting and verificationRange
4Antenna Definition Antenna interaction A device for transmitting and receiving electromagnetic radiationMaking a guided electromagnetic wave travel in free space“A means for radiating or receiving radio waves”, IEEE StdAntenna interactionAs a result, the antenna and its surrounding needs to be regarded as a unit since they interact strongly
5Electromagnetic radiation c = f f = 2.45GHz = 12 cmX-Ray, Light, Radio, Heat - It is all the same: Photons!
6Influencing antenna size Material choice = permitivity FR4 in case /2 antenna, half the lengthMatchingAdding capacitance or inductance by means of electronic components.Geometryantenna typeshape (helix, spiral, meander etc.)utilise part of the application.
7Frequency bands for Mobile phones MHzNMT and CountriesEAMPS USAGSM EuropeEGSM EuropeNTT JapanDCS EuropePCS USAUMTSISM WorldwideVisible light THzISM = Instrumentation, Scientific, MedicalBluetoothWLAN (IEEE )HomeRF
8Frequency bands for data communication WLANMHz On the way outGHz AvailableGHz Available soonGHz Will perhaps be availableBTGPS1575,42 MHz Available
9Antenna parameters Lobes Gain Polarisation Efficiency Frequency Band Knowledge about the antenna parameters is needed in order for us to understand our customers and vice versa.LobesGainPolarisationEfficiencyFrequency BandRadiation pattern
10Radiation pattern 3D Radiation pattern with lobes Linear plot of power pattern
11Radiation intensityRadiation intensity in a given direction, , is defined as the power radiated from an antenna per unit solid angleRadiation intensity for an isotropic source:where is the total power radiated by the source
12DirectivityDirectivity is a measure of how an antenna concentrates the radiated power in a particular direction.Directivity is the ratio of the intensity, in a given direction, to the radiation intensity that would be obtained if all the power radiated by the antenna were radiated isotropically:a unitless figure
13GainGain is a measure of how an antenna concentrates the radiated power in a particular direction.Gain is the ratio of the intensity, in a given direction, to the radiation intensity that would be obtained if all the power was accepted by the antenna and was radiated isotropically:a unitless figure dBi
14Gain/Directivity Isotropic Omnidirectional Lobes Dipole = Donut Normally measured in dBRelative unitdBi: relative ideal isotropicIsotropic radiator has 0dBi gaindBd: relative ideal dipole (1 dBd dBi)If a gain value is given without any direction, it is the maximum gainMore power in one direction at the expense of other directions
15Gain: good/bad Stationary or mobile application Important to reach out in a certain directionWall or corner positionLess important inside a small room due to reflectionsRegulation limits ETSI EN Max 100mW eirp FCC peak power reduction when antenna gain over 6dBi
16Decibel Used to compare two figures with each other Describes better measurable steps than fractionsAlways unitlessdBdBi (isotropic)dBd (dipole)dBm (miliwatt)dBw (Watt)
17Antenna efficiency (total) Good figure of merit, especially for small antennasRatio of the power sent to the antenna to the power radiated by the antennaUnitlessIdeal 1Often given in percentRadiated efficiency is given as the ratio of the power accepted by the antenna to the power radiated by the antenna, and is thus higher than totoal efficiency if there is losses in strip line, components etc.The average gain in all directions is the same as the efficiency.
18Polarization Circular Linear Small antennas have no clear polarization Reflection affects polarizationMaximum power transfer requires polarization match between antennas in free space. In reality, polarization is not a problem.
20EVOLUTION 1. Monopole L- antenna F- antenna PIFA (Wire inverted F-antenna)PIFA(Planar inverted F-antenna)Move feeding point to 50 Ohm to create high inductance. High surface current = high power loss/4 - PinGood, but very tall, 37 Ohm/4 - PinBetter, medium tall, but capacitivity to earth planeCreate larger area to minimise surface resistance and power losses
21EVOLUTION 2. /2 - PATCH /4 - PATCH = PIFA That point is connected to earth and the antenna size is reduced by half.LargeIn the middle of the antenna the Voltage = O v.
22Microstrip Printed on PCB Low cost Although thin, quite large Depends on variation in board materialFree space-dependentNarrow bandwidth
24Your BenefitShorter time to marketProject support from A to ZHigh performance solutions
252.4 GHz antenna concepts for a wide range of applications Snap-inICMHead setsLaptopSWIVELMobile phonesInstrumentsSMDDigital pensDonglesPDA’sPCMCIA-cards
26External Concepts Swivel TITANISGain 1.6 dBiEfficiency: 75%VSWR <1.5:1Length : 50 mmBasic dataExternal 1/2 wave dipole Independent of ground plane withinternal matching netTypical ApplicationsDevelopment kits, Prototypes, Printers , InstrumentsCustomer benefits- Easy implementation - no matching & tuning - Perfect for feasibility studies- High performance - reliable data transfer- Designed for flexible mounting - rotating antenna bladeVIRAGOGain 1.6 dBEfficiency: 75%VSWR <1.5:1Length : 50 mm
27Internal concepts Snap-in FLAVUSGain 1.4 dBiVSWR <1.4:1Efficiency: 62 %Dim (mm) : 8x27x3 mmGeneralInternal 1/2 wave dipole independent of ground plane with external matchingApplicationsMobile & desktop computers, Measuring instrumentsaudio equipment, Automotive systems, Note booksCustomer Benefits- Easy & fast implementation - 1 working week- High performance - reliable data transfer- No soldering - Designed for pick & place - Proven conceptCRISPUSGain 1.6 dBiVSWR <1.5:1Efficiency: 73%Dim (mm) : 20x30x4
28ICM concept General Internal Case Mounted antenna 1/2 wave dipole ICM - Single bandGeneralInternal Case Mounted antenna 1/2 wave dipoleindependent of ground plane with external matching,customized design of contact points and antenna.ApplicationsPDA’s, handheld devices, instruments, etcCustomer benefit- High performance where space is restricted- Flexible mounting - type of fastening- Fast implementation compared to ceramic - Requires little space - only contact pad- Multi purpose antennas GHz & GSMICM - Multi BandICM - Dual band
29SMD concept General Internal 1/4 wave PIFA dependent of ground plane. ApplicationsMobile & desktop computers, Measuring instrumentsaudio equipment, Automotive systems, Note booksCustomer benefits- Easy and fast implementation - 1 week - Designed for SMD soldering- High performance - reliable data transfer- Small in size - Less sensitive than ceramicMICAGain 3-5 dBiVSWR <2.5Efficiency: 60%Dim (mm) : 19x3.2x3.2
30CUSTOMER Ramp-up gigaAnt Antenna delivery STARTUP PROJECT PRODUCTION selectionFootprintsAppli.notessamplesReview ofdesign& PCBDesign ofprototypePrototypereadyRamp-upSTARTUPPROJECTPRODUCTIONgigaAntAntennaselectionguidanceReview of PCB designTuning &MatchingVerificationof prototypeFinalreportAntenna delivery
32Implementation issues Internal / ExternalStandard or custom made Time schedule, estimated production volume, Available volume in deviceIn-House or RF-Partner with know-howRequired performanceSpace limitationsOperating environmentContinuous dialogUnderstanding for RF-problemsEarly access to chassisEarly access to populated PCB
33Antenna implementation: Standard concept AdvantagesWell known electrical performanceEnvironmentally / mechanically testedSpecifications and application note availableTools already manufacturedFast implementationLower pricePossible solution for low volume applicationsDisadvantagesHard to fulfill special requirementsSize/Shape might not fit available volume optimal (form factor)
34Antenna implementation: Standard concept Common steps (RF point of view)Advice customer in antenna choices and placement Performance, Available volume, Hands…Review PCB-drawing for RF-mistakes Feeding (length, path, dimensions), Matching location, Ground plane, Through plating, Calculations…Build mock-up Antenna performance, Matching, Covers, Surrounding components, Hidden things…Final product Matching, Tuning, MeasurementsReport Antenna performance, MatchingFollow up
35Antenna implementation: New concept AdvantagesMeet special requirementsUse all available volume in order to increase antenna performanceChance to start a new standard conceptDisadvantagesUncertain antenna performanceNo documentation availableAlways a risk in new toolsUses lot of resources and time in organizationMight only fit one applicationCostly in small volumes
36Antenna implementation: New concept Common steps (RF point of view)Advice customer in antenna choicesBuild mock-up, often several in a developing processCheck PCB for RF-mistakesFind subcontractor for tools, material, manufacturingTest products from subcontractorsOrder tools (prototype tool, soft tool, hard tool)Environmental test on parts from toolsChanging toolsAfter receiving PCB, matching and measurementChanges in PCB and covers are commonSeveral reports during the processFollow up
37Ceramic Antennas Pros Small size Compact surface mount units Cons Large ground plane dependence -> high of non-working antennaNarrow bandwidthLow efficiencyHand sensitive
38Mechanical design Parameters that affect performance Covers: Material, Shape, Colors, MetalisationFree space / Office environmentHumansStationary/mobile applicationReflections from walls etcEnvironmental factors
39Electrical design Parameters that affect performance Ground plane PositionSurrounding componentsTransmission line dimensionsFeeding (balanced/unbalanced)MatchingThrough platings
40StripsEven if calculated to be 50 ohm, if too thin it introduces large losses due to distributed parasitic coupling to ground plane.Long strips should be avoided because of the high losses at 2.4 GHz in general FR-4.Sharp bend should be avoided because of the parasitic effects. Better to split up into two bends or a large radius.Some effects could be avoided if corner is chamfered.
41Different type of strip lines Co-planar waveguideMicrostripGrounded co-planar waveguideStripline
42Antenna impact on the PCB Antenna require certan ground planeOr lack of ground planeBe aware of antenna user interactionRF close to radio chip because of feedingArea for matcing componentsSurrounding components (battery, contacts, cables, loudspeaker)Outside shielded areas
44Receiver characteristics 0dBm TX Power-40 dBm RX 1m-70 dBm RX 10m-90 dBm noise floorSpecification requires -70dBmSome radio chips down to -90dBmThe actual sensitivity level is defined as the input level for which a raw bit error rate (BER) of 0.1% is met. The requirement for a Bluetooth receiver is an actual sensitivity level of –70 dBm or better. The receiver must achieve the –70 dBm sensitivity level with any Bluetooth transmitter compliant to the transmitter specificationThe 10 meter range is not included in Bluetooth specification.
45Antenna rangeFriis transmission equation relates operating range, power and gainHard partition office decreases range increases nTwo antennas with 2 dBi gainRadio fulfilling -70 dBm.
47Network AnalyserMeasuring S-parameters in frequency domain VSWR, Return Loss, Smith ChartPhaseEvaluate matchingEvaluate undesired lossesCoverage measurements
48VSWR (Voltage Standing Wave Ratio) Determination of matching between the antenna and the transceiver in the prototypeEssential to minimising power losses
49VSWRIdeal 1:1Typical 2:1Minimized by matching networkPower sent to the antenna should be accepted and not reflected.
50Return Loss Used to describe antenna Related to VSWR Narrow / Spread bandS11-parameterThe analyzer sweeps frequencies and register reflection from antenna
51Smith Chart is used for matchinng and adjusting antennas Based on the result of Smith Chart measurements gigaAnt can carry out network matchingAntenna ImpedanceStrip line impedanceSmith Chart is used for matchinng and adjusting antennas
52Transmission measurement Losses in feedingLosses in connectionsIsolation between antennasS12-parameter
543D radiation patternRadiation pattern of the antenna when mounted in the actual deviceNeeded to ensure the required functionality. It is easily seen if an antenna really is sufficiently omnidirectional or if a directional antenna has the expected radiation pattern.
563D radiation pattern measurement Anechoic chamber with shielding and absorbersAdvanced controlling of probe positionTwo probes collecting both polarisationsNetwork analyzer to collect dataNearfileld to farfield transformationMeasure one frequency at the timeDUT is rotating phi while probes are stepping theta.
57Radiation PatternPattern from Bluetooth swivel under development measured in Moteco´s anechoic chamber.A 3D scan reveals things a 2D scan never could.
59SAR - (Specific Absorption Rate) Governmental/ International agreement on how much a transmitting unit is allowed to heat tissueWe verify compliance with national/international regulations = Tissue conductivity (S/m)E = Electric field strength in tissue (V/m) = Tissue dencity (kg/m3)
60SAR Not necessary for the 10 meter (1dBm) Bluetooth standard Necessary for the 100 (20dBm) meter Bluetooth standardEurope 2.0 mW/g over 10g cube tissueUSA 1.6 mW/g over 1 g cube tissueSAR measurements are difficultRequires expensive and advanced equipment
61Field measurementExamination of the electrical and magnetic fields on the surface of the product (prototype) and antennaImportant measurements the result is used during the development process to verify functionality and to ensure SAR compliance
62Summary Antenna Development Simulation is a useful tool, but not perfectThe PCB is very essential to make a good antenna.Prototypes are an essential part of the developmentContinuous measurement and verification after changes in the surroundingsExperience and know-how are important for a good resultIteration between design and measurement is needed
63You need the right antenna to communicate ! What ?