RFID Frequency Overview to Application fit

Transcription

1 RFID Frequency Overview to Application fit 1

2 The Radio Spectrum RFID tags exhibit different characteristics at different frequencies and it is highly unlikely that there will ever be one tag that can be used with all applications This presentation looks at the characteristics of battery-less tags operating in the different bands and their associated International standards : RADIO FREQUENCY SPECTRUM 100 khz 1 MHz 10 MHz 100 MHz 1 GHz 10 GHz LF MF HF VHF UHF 120 ~ 134 khz Low Frequency (ISO11784/5 ISO14223) MHz High Frequency (ISO15693/ ISO 14443/ ISO ) 2.45 GHz 5.8 GHz 850 ~ 960 MHz (Europe / US / Japan) UHF (ISO , EPCglobal) 2

3 Transferring Energy A battery-less tag gets its energy from the antenna s signal Reader Antenna The radio waves are generated by the reader s antenna. Tag A tag in the RF field uses energy from the radio waves to respond to the reader s commands 3

4 Transferring Energy to the Tag Radio Waves Radio signals are electromagnetic waves, having a magnetic component (H-Field) and an electric component (E-Field) ELECTRIC (E) FIELD LF & HF systems use the Magnetic field to transfer power by induction. This field has a well defined zone but the strength of this field falls off quickly. MAGNETIC (H) FIELD UHF systems use the Electric field to transfer power by capacitive coupling. The strength of this field doesn t fall off as quickly, so potentially longer read distances are possible. Reflections mean that the reading zone is less well defined. 4

5 System Configuration foil antenna Antenna Command / Data / Energy HF (FDX) Data resonance capacitor + tuning IC res. capacitor ferrite coil IC Charge up capacitor LF (HDX) Reader 5

6 Low Frequency Systems 100 khz 1 MHz 10 MHz 100 MHz 1 GHz 10 GHz LF MF HF VHF UHF 120 ~ 134 khz Low Frequency (ISO11784/5 ISO14223) MHz High Frequency (ISO15693/ ISO 14443) 2.45 GHz5.8 GHz 860 ~ 960 MHz (Europe / US / Japan) UHF (Emerging standards) 6

7 LF Characteristics Characteristics of Low Frequency Systems Most tags operate at frequencies between 120 to 134 khz. These frequencies have wavelengths of approximately 2500 m (8200 ) LF radio waves will pass through all materials, with the exception of metals, with almost no reduction in read range. LF frequencies allow adequate power levels to be used worldwide and without special licensing. Allows compact packaged tag designs. Ferrite cores and glass housing can be used. (>10 yrs life immersed) Tags, typically designed for lifetime use, are more expensive than those at higher frequencies The magnetic field although falling off quickly, creates a reliably defined homogeneous read zone. Data-rates are relatively slow though and systems capable of reading multiple tags at the same time are rare. Information can also be written to the tags (Read/Write technology) 7

8 FDX System Overview READER TRANSPONDER CONTROL RX/ DECODE POWER CODE TX RX An FDX AM System Transmitter on 100% of time Response at different frequency Fighting against its own noise Raising the power raises the noise 8

9 HDX System Overview READER TRANSPONDER POWER CONTROL TX/ CONTROL RX/ DECODE CODE TX RX An HDX FM System Transmits in bursts Charge Capacitor Tags respond in radio silence Raising the power doesn t raise the noise 9

10 LF - HDX System Uplink Transmission Frequencies: 123.2/134.2 khz Modulation: FM (FSK) Coded: NRZ Bandwidth: 25 khz 10

11 AM vs. FM Uplink FM System AM-Noise Uses Frequency Shift keying RX Exhibits signal capture allowing the reader to discriminate between tags close together by locking onto the strongest signal. More noise immune than AM AM System Uses Amplitude Shift Keying Transmitter 100% on or Off AM-Noise Easier to implement Δa = Information f 1 f 2 Δf = Information a max a min Amplitude 11

12 Examples of LF tags LF Transponders 32mm and 23mm glass capsule transponders 12

13 LF Transponders Customized packages 13

14 LF Applications Typical requirements LF Applications Lifetime ID Compact robust packages Working in harsh, industrial and outdoor conditions Defined read zones 14

15 Livestock Applications LF Applications (1) Lifetime ID under harsh, outdoor conditions Cattle Sheep Fish and Wildlife 15

16 LF Applications Livestock ID Accredited Identification schemes Trace ability assurance Farm Management On Farm On the move Defined read zones 16

17 General Applications All weather conditions LF Applications Leisure Facility Management Waste Management Sportstiming 17

18 General Applications Defined read zone LF Applications Automobile Immobilisers SpeedPass 18

19 LF Applications General Applications Life time ID security Container terminals Rotterdam, Hamburg Automatic guided Vehicles Navigation System Tags in the surface, reader on the vehicles 19

20 LF Applications General Applications life time ID security Holland flower auctions Over roll cages Floor chain readers On the fly read points On-time delivery after auction Container management Tr & Tr goods and equipment 20

21 LF Readers TI Standard Versions 21

22 LF Readers Customized packages 22

23 LF Antenna s TI Standard Versions 23

24 LF Antenna s Customized Versions 24

25 LF Standards LF applications utilize the strengths of this frequency. The ability to read through materials; to be able to read in wet and dirty conditions and a well defined read zone have seen these tags used in livestock, waste management applications and payment systems. For Livestock the following standards exist: ISO RFID of animals Code structure ISO RFID of animals Technical concepts ISO RFID of Animals Advanced transponders; Air Interface ISO RFID of Animals Advanced Transponders; Protocol It is likely that ISO will become part of the generic ISO standard:- ISO Physical Layer. Anti-collision and Protocol for systems less than 135 KHz (Final Committee Draft) For waste management too, standards are emerging: DIN This is currently a German national standard but is expected shortly to emerge as a European standard 25

26 High Frequency Systems 100 khz 1 MHz 10 MHz 100 MHz 1 GHz 10 GHz LF MF HF VHF UHF 120 ~ 134 khz Low Frequency (ISO11784/5 ISO14223) MHz High Frequency (ISO15693/ ISO 14443/ ISO ) 2.45 GHz5.8 GHz 860 ~ 960 MHz (Europe / US / Japan) UHF (Emerging standards) 26

27 HF Characteristics Characteristics of High Frequency Systems Tags operate at MHz. This frequency has a wavelength of approximately 22 m (72 ) The radio waves will pass through most materials, with the exception of metals, but some reduction in read range will occur. This frequency is now available at adequate power levels worldwide and without special licensing. Tags are mainly in label (flat) format The magnetic field, although falling off quickly, creates a reliably defined homogeneous read zone. Systems are capable of reading multiple tags at the same time at this higher frequency. Information can also be written to the tags (Read/Write technology) 27

28 Examples of HF Tags HF Transponders Smart Label inlays CD inlays Laundry Tag Wireless Payments (ISO 14443) AMEX Express Pay 28

29 Product Management HF Applications (1) Tray Programming Courtesy of Intellident Multiple Tray Identification Courtesy of Intellident 29

30 Stock Management Defined read zone HF Applications (2) Library Systems Management On-Shelf Identification 30

31 Customer Loyalty HF Applications (3) Intelligent Changing Facilities 31

32 HF Applications (4) Payments American Express Shell Canada 32

33 HF Standards At MHz standards exist for both Proximity & Vicinity applications Proximity applications are mainly concerned with ticketing and payments, where reading distances are up to 100 mm (4 ): ISO/IEC Identification cards -- Contactless integrated circuit(s) cards Proximity cards Vicinity applications include product identification and tracking, and would be capable of identifying objects up to 1m (39 ): ISO/IEC Identification cards -- Contactless integrated circuit(s) cards Vicinity cards There is also an emerging generic ISO standard for RFID systems operating at MHz: ISO/IEC Physical Layer, Anti-collision and Protocol for MHz systems Additionally there is also a proposed EPC recommendation for MHz MHz ISM Band Class 1 Radio Frequency Identification Tag Interface 33

34 Ultra High Frequency Systems 100 khz 1 MHz 10 MHz 100 MHz 1 GHz 10 GHz LF MF HF VHF UHF 120 ~ 134 khz Low Frequency (ISO11784/5 ISO14223) MHz High Frequency (ISO15693/ ISO 14443) 2.45 GHz5.8 GHz 850 ~ 960 MHz (Europe / US /.Japan) UHF (Emerging standards) 34

35 UHF Characteristics Characteristics of Ultra High Frequency Systems Tags operate at slightly different frequencies in various parts of the world MHz in Europe & parts of Asia, 902 ~ 915 MHz in the USA and more recently, the 952~954 MHz band has been proposed for use in Japan. The wavelength is around 300 mm (12 ) Currently, this frequency does not have at the same power levels worldwide. In the USA the limit is 4W EIRP, in Europe the limit has been raised to 2W ERP - equivalent to 3.28W EIRP. The limits in Japan are the same as North America. UHF radio waves do not readily pass through materials and water/ice are a particular problem. Metals reflect signals, liquids absorb the signals. Tags tend to be long and are mainly applied as labels (flat format). When tags are made more compact, performance can drop. To optimise performance, tags have to be designed for each type of material they are applied too. The electric field gives extended reading performance but defining the reading zone can be problematic. Systems are capable of reading multiple tags and extracting large amounts of data in a short time, at these higher frequencies. 35

36 Examples of UHF tags UHF Characteristics Copyright 2005 Texas Instruments 36

37 UHF Applications (1) Garment-on-rail Tracking Garment distribution Marks and Spencer 37

38 Pallet Level Applications UHF Applications (2) Pallet Tracking Pallet load Tracking 38

39 UHF Applications (3) Antenna Antenna Antenna Antenna Identification at the Dock Door Pallet load Tracking 39

40 Emerging UHF Standards Two main bodies are currently developing standards: ISO/IEC EPCglobal ISO defines worldwide air-interface protocols for UHF Tag operations An EAN/UCC initiative (out of work by the MIT Auto-ID Center) to create a global Electronic Product Code structure to identify each individual item but also includes air interface (UHF) definitions Eventually the EPC Gen 2 standard will be incorporated into ISO as Type C. 40

41 Inlay Characteristics - Moisture Influence of materials on Read Range Read Range % Paper Plastic Water Film Immersion Anticipated read range but actual may vary depending on manufacturer and antenna design. LF HF UHF 41

42 Transponder Comparative Read Ranges Size Does Matter 7000 Copyright 2005 Texas Instruments READING RANGE (mm) LF WEDGE COMPARATIVE READ RANGE LF KEYFOB LF GLASS LF DISC HF INLAY LF MOM LF 82-mm DISC UHF Single Antenna 400 Anticipated read range but actual may vary depending on manufacturer and antenna design. 42

43 Frequency Selection Summary Frequency LF HF UHF 125 ~ 135 khz MHz 850 ~ 960 MHz Read Range 0.5 ~ 1 m < 1m > 3m Cost Relatively expensive Less expensive Least expensive Penetration Excellent of materials Poor Affected No To some extent Yes by water? Power source Passive (Inductive) Passive (Inductive) Passive (Capacitive) Data Rate Slower Faster Reading Poor Good Very Good Multiple tags Applications Car immobilisers, Animal Pharma, Libraries Pallet/ Case tracking, Tolls identification, POS Baggage tracking, Tickets Baggage tracking Payments, Passports 43