Panasonic - NFC TAG天线设计指南

Version 1.20Notice : All trademarks are the property of their respective owners. “ FeliCa " is a registered trademark of Sony Corporation.

" Nexus S “ and " Nexus " are registered trademarks of Google Inc.. " Galaxy " is a registered trademark of Samsung Electronics Co., Ltd.. “ ELUGA ” is a registered trademark of Panasonic Corporation.Contents

1. Introduction (3)

1.1 Purpose of this Guide (3)

2. Designing the Antenna (4)

2.1 Antenna Design Flow (4)

2.2 Determining the Size of Antenna [STEP 1] (5)

2.3 Determining the Specifications of Antenna [STEP 2] (5)

2.3.1 Measurement Results of Communication Distance (6)

2.4 Setting up the Antenna Board [STEP 3] (10)

2.4.1 Reference Example of Antenna Board (11)

2.5 Determining Resonant Capacitor Value [STEP 4] (12)

2.5.1 Measuring Antenna Equivalent Circuit Parameters [STEP 4-1] .. 13

2.5.2 Calculating Resonant Capacitor Value [STEP 4-2] (14)

2.5.2.1 Calculation Example of Resonant Capacitor Value (15)

2.5.3 Determining Proper Resonant Capacitor Value [STEP 4-3] (16)

2.6 Checking the Operation of NFC Tag [STEP 5] (17)

2.6.1 Measuring the Communication Distance (17)

2.6.2 Checking the Voltage of Antenna Pin (18)

3. Reference (19)

3.1 Antenna Class Based on ISO/IEC14443 (19)

3.2 Antenna Coil Specifications in NFC Forum (20)

3.3 How to Measure the Voltage of Antenna Pin (21)

4. Revision History (22)1. Introduction

1.1 Purpose of this Guide

This guide provides how to design the antenna to be connected to the NFC tag LSI.

Figure 1 shows an outline of the system using an NFC (Near Field Communication) tag.

NFC Tag

Carrier Frequency: 13.56 MHz

R/W : Reader/Writer (smartphone, etc.)

Host : Host

RF I/F : RF interface

Control Logic : Control logic

Serial I/F : Serial interface

Figure 1Schematic NFC Tag Communication System2. Designing the Antenna 2.1 Antenna Design Flow

Design the antenna for tag following the flow below.

2.2 Determining the Size of Antenna [STEP 1]

Determine the allowable antenna size, based on the specifications of NFC tag applications.

Refer to the measurement results (Table 1) of communication distance from our NFC tag LSI.

2.3 Determining the Specifications of Antenna [STEP 2]

The parameters for antenna specifications used in this guide are defined in Figure 2 Antenna Coil Outline Drawing.

Based on the measurement results (Table 1) of communication distance from our NFC tag LSI, determine the specifications of antenna (number of turns, track width, spacing). Figure 2 Antenna Coil Outline Drawing

Size x

Size y

Shape of antenna

Antenna inductance

[µ H] Resonant

capacitor

[pF]

Communication distance [mm]

Size [mm2] Track

width

[mm]

Spacing

[mm]

Number

of turns

[turn]

Without external DC

supply

With external DC

supply

FeliCa Type B FeliCa Type B

72 x 42 0.5 0.5 1 0.242 551 52 42 60 55

2 0.734 1 55 47 62 60

3 1.442 77 52 46 59 60

4 2.259 42 49 4

5 5

6 59

5 3.171 24 47 43 53 58

2.3.1 Measurement Results of Communication Distance

Table 1 shows the measurement results of communication distance between smartphone and our prototype NFC tag.

Table 1-1 Measurement Results of Communication Distance

(Note 1) Nexus S (manufactured by Samsung) is used as smartphone.

(Note 2) Resonant frequency is calibrated to 13.56 MHz.

(Note 3) These data are the results measured using our prototype NFC tag and do not guarantee the communication distance from your NFC tag.Shape of antenna

Antenna inductance

[µ H] Resonant

capacitor

[pF]

Communication distance [mm]

Size [mm2] Track

width

[mm]

Spacin

g

[mm]

Number

of turns

[turn]

Without external DC

supply

With external DC

supply

ＦｅｌｉＣａType B ＦｅｌｉＣａType B

40×30 0.1

0.1

1 0.18

2 742 28 26 36 36

2 0.60

3 211 38 3

4 46 44

4 1.992 54 40 36 47 48

0.3

2 0.560 229 39 35 47 45

4 1.726 63 41 37 48 49 0.3

0.1

2 0.497 260 46 39 5

3 50

4 1.721 63 41 37 48 50

0.3

1 0.153 88

2 38 3

3 45 43

2 0.470 275 47 39 54 50

3 0.908 13

4 46 41 53 52

4 1.430 78 4

5 40 51 52

5 2.031 50 43 39 50 51

0.5 0.5

1 0.138 979 4

2 36 49 46

2 0.405 321 49 41 56 52

3 0.753 16

4 49 42 5

5 53

4 1.149 101 47 42 54 53

5 1.582 72 44 41 48 50

(Note 1) Nexus S (manufactured by Samsung) is used as smartphone.

(Note 2) Resonant frequency is calibrated to 13.56 MHz.

(Note 3) These data are the results measured using our prototype NFC tag and do not guarantee the communication distance from your NFC tag.Shape of antenna

Antenna inductance

[µ H] Resonant

capacitor

[pF]

Communication distance [mm]

Size [mm2] Track

width

[mm]

Spacing

[mm]

Number

of turns

[turn]

Without external DC

supply

With external DC

supply

FeliCa Type B FeliCa Type B

12×10 0.1 0.1 8 1.251 95 23 20 28 28 12 2.084 51 22 19 26 28 16 2.787 34 20 18 24 26

Shape of antenna

Antenna inductance

[µ H] Resonant

capacitor

[pF]

Communication distance [mm]

Size [mm2] Track

width

[mm]

Spacing

[mm]

Number

of turns

[turn]

Without external DC

supply

With external DC

supply

FeliCa Type B FeliCa Type B

25×20 0.3 0.3 1 0.093 1463 18 17 25 25

2 0.268 496 38 32 44 41

4 0.777 161 39 34 4

5 44

5 1.073 112 38 34 43 43

(Note 1) Nexus S (manufactured by Samsung) is used as smartphone.

(Note 2) Resonant frequency is calibrated to 13.56 MHz.

(Note 3) These data are the results measured using our prototype NFC tag and do not guarantee the communication distance from your NFC tag.

(Note 1) Nexus S (manufactured by Samsung) is used as smartphone.

(Note 2) Resonant frequency is calibrated to 13.56 MHz.

(Note 3) These data are the results measured using our prototype NFC tag and do not guarantee the communication distance from your NFC tag.

Table 1-4 Measurement Results of Communication Distance

Shape of antenna

Antenna inductance [µ H]

Resonant capacitor [pF] Communication distance [mm] Size [mm 2] Track width [mm] Spacing [mm] Number of turns [turn] Without external DC

supply With external DC

supply FeliCa Type B FeliCa Type B 72×42 0.5 0.5 2 0.734 1 55 47 61 60 40×30 0.5 0.5 2 0.405 321 48 40 53 51 25×20 0.3 0.3 4 0.777 161 37 32 42 42 12×10

0.1

0.1

8

1.251

95

20

17

24

25

Shape of antenna

Antenna inductance [µ H]

Resonant capacitor [pF] Communication distance [mm]

Size [mm 2] Track width [mm] Spacing [mm] Number of turns [turn]

Without external DC

supply With external DC

supply FeliCa Type B FeliCa Type B 72×42 0.5 0.5 2 0.734 1 40 34 45 41 40×30 0.5 0.5 2 0.405 321 38 31 42 35 25×20 0.3 0.3 4 0.777 161 28 24 31 29 12×10

0.1

0.1

8

1.251

95

17

16

19

20

(Note 1) ELUGA (manufactured by Panasonic) is used as smartphone. (Note 2) Resonant frequency is calibrated to 13.56 MHz.

(Note 3) These data are the results measured using our prototype NFC tag and do not

guarantee the communication distance from your NFC tag.

Table 1-5 Measurement Results of Communication Distance Between GALAXY Nexus and our prototype NFC Tag

Table 1-5 Measurement Results of Communication Distance Between ELUGA and our prototype NFC Tag

(Note 1) GALAXY Nexus (manufactured by Samsung) is used as smartphone. (Note 2) Resonant frequency is calibrated to 13.56 MHz.

(Note 3) These data are the results measured using our prototype NFC tag and do not

guarantee the communication distance from your NFC tag.

2.4 Setting up the Antenna Board [STEP 3]

Based on Figure 3 Recommended Circuit Diagram, set up the antenna

board.

(Note 1) Use a resonant capacitor with a withstand voltage of at least 50 V. (Note 2) The value of resonant capacitor should be adjusted as needed, so

we recommend a pattern design that allows multiple capacitors to be mounted.

Figure 3 Recommended Circuit Diagram

2.2μL

Double-sided glass epoxy board (FR-4) Thickness of board: 1.0 mm

Thickness of track: 60 mm (Copper)

Figure 4 shows a reference example of antenna board.

2.4.1 Reference Example of Antenna Board

Figure 4 Reference Example of Antenna Board

LSI mounting side

0.5

0.5

2.5 Determining Resonant Capacitor Value [STEP 4]

Determine the value of resonant capacitor following the flow below.

2.5.1 Measuring Antenna Equivalent Circuit Parameters [STEP 4-1]

Impedance Analyzer

(HP4194A)

< Measurement example for HP4194A >

(1) Set the impedance analyzer’s start and stop frequencies to 13 MHz

and 14 MHz, respectively.

(2) Make a single measurement in |Z| -θ mode.

(3) Push the “MoreMenu > Equivalent Circuit” button to select the same

equivalent circuit as the figure above.

(4) Push the “Calculate” button to obtain L coil , R coil , and C coil values.

(5) When C coil is small, and cannot measure by this method definitely, as

C coil = 0pF, make a measurement in L s -R s mode.

coil

Antenna Equivalent Circuit

Figure 5 shows how to measure the antenna equivalent circuit parameters. Here, the parameters represent L coil , R coil , and C coil .

Antenna equivalent circuit parameters can also be calculated utilizing an

electromagnetic simulator.

Figure 5 How to Measure the Antenna Equivalent Circuit Parameters

2.5.2 Calculating Resonant Capacitor Value [STEP 4-2]

R L

Based on equation (1) derived from the NFC tag equivalent circuit shown in Figure 6, calculate the resonant capacitor value.

In the equivalent circuit of Figure 6, the resonant frequency (f r ) is given by equation (1).

… Equation (1)

Figure 6 Equivalent Circuit of NFC Tag

)C C C (L 21f in res coil coil r ++=・・π・

2.5.2.1 Calculation Example of Resonant Capacitor Value Calculate the resonant capacitor value (C res

) by substituting the antenna equivalent circuit parameter values into equation (1).

This example (MN63Y1213) assumed it C in = 15.5pF from item C9 of the product standard.

Substituting the antenna equivalent circuit parameters (L coil = 1 µH, C coil = 2 pF) and the resonant frequency (f r = 13.56 MHz), gives

Hence, the resonant capacitor value C res = 120 pF. )

pF 5.17C pF 2(H 121MHz 56.13res ++µ=・・π・

Figure 7 shows how to measure the resonant frequency. While the

resonant capacitor with a value calculated in [STEP 4-2] and the NFC tag LSI are mounted on the antenna board, measure the resonant frequency to determine the proper resonant frequency.

If the resonant frequency has not been 13.56 MHz, adjust the resonant capacitor value. If the frequency is high, increase the capacitor value; if low, decrease it.

Figure 7How to Measure the Resonant Frequency < Measurement example >

(1) Perform the calibration with no sense coil connected in OPEN mode.

In SHORT mode, do it with a sense coil connected.

(2) Do not apply a voltage to the NFC tag LSI’s power supply (VDDEX)

and GND (VSS).

(3) Set the start and stop frequencies of the impedance analyzer to 10

MHz and 15 MHz, respectively.

(4) Set to R-X mode.

(5) Measure the resonant frequency (f r) at which the resistance R is

maximum.

2.6 Checking the Operation of NFC Tag [STEP 5]

Mount the NFC tag LSI on the antenna board and measure the following items to verify normal operation.

(1) Communication distance

(2) Voltage of antenna pin 2.6.1 Measuring the Communication Distance

< Measurement example >

(1) Move the NFC tag closer to a smartphone until NFC communication succeeds.

(2) Then, measure the distance from the smartphone.

Based on the method for measuring the communication distance shown in Figure 8, measure the communication distance from smartphone.

Verify whether the result meets the specifications of your model.

Smartphone

Communication

Distance

NFC Tag

NFC Tag LSI

Antenna Resonant Capacitor

Figure 8 How to Measure the Communication Distance

2.6.2 Checking the Voltage of Antenna Pin

Shape of antenna

H max

[A/m] Voltage between VB and VSS pins

[Vpp]

Size [mm2] Track width

[mm]

Spacing

[mm]

Number of turns

[turn]

72 x 42 0.5 0.5 1 7.5 21.8

2 7.5 17.1

3 7.5 14.6

40 x 30 0.5 0.5 2 8.5 18.5

3 8.5 15.3

4 8.

5 13.4

25 x 20 0.3 0.3 3 (8.5) 11.8

4 (8.5) 10.4

5 (8.5) 10.2

12 x 10 0.1 0.1

8 (8.5) 6.9 12 (8.5) 6.7 16 (8.5) 6.5

Table 2 shows the measurement results of antenna pin voltage of our prototype NFC tag.

Based on Table 2, verify that the following product standards are satisfied: Parameters D10 (21 Vpp or less for VB-VSS pins)

Figure 9 Voltage Waveform on VA and VB Pins (Note 1) These data are the results measured

using our prototype NFC tag and do not

guarantee your NFC tag’s

antenna pin voltage.

(Note 2) If using a large-sized antenna, make sure that the antenna pin voltage does not

exceed the values specified in parameters D10.

(Note 3) The maximum magnetic field strength of

25*20 and 12*10size assume it 8.5A/m by limitation of the measuring equipment.

Table 2Measurement Results of Antenna Pin Voltage V

3. Reference

3.1 Antenna Class Based on ISO/IEC14443

Table 3 shows the antenna class based on ISO/IEC14443-1,2. Operating magnetic field intensity varies with antenna class.

Table 3 Antenna Class Based on ISO/IEC14443

NFC FORUM

-NFC Analogue Specification- 2/15/2011

Wide [mm]

Long [mm] Number of turns [turn]

Track width [mm] Spacing [mm] LISTENER-1 72.1 42 4 0.5 0.5 LISTENER-3 46.3 32.3 5 0.3 0.3 LISTENER-6

25

20

5

0.3

0.3

3.2 Antenna Coil Specifications in NFC Forum

LISTENER-1

LISTENER-3

LISTENER-6

Figure 10 shows the antenna coil specifications reported in the NFC Forum on February 15, 2011.

Figure 10 Antenna Coil Specifications in NFC Forum

71.6mm

41.5m m

R=2.0mm

R=3.0mm R=5.0mm

R=4.0mm

TRACK WIDTH = 0.5mm 42.8mm

27.0m m

150.0mm

54.0m m

46.0mm

TRACK WIDTH = 0.3mm

32.0m m

42.8mm

27.0m m R=2.0mm R=2.6mm

R=3.8mm R=3.2mm

R=4.4mm

150.0mm

54.0m m

24.7mm

TRACK WIDTH = 0.3mm

19.7m m

42.8mm

27.0m m R=1.0mm

150.0mm

54.0m m

Set up the measurement environment as shown in Figure 11 to measure the voltage of antenna pin.

For more information on how to test an NFC tag, refer to ISO/IEC10373-6.

Place the

boards with

the same

spacing

(37.5 mm)

Figure 11 Schematic Measurement Environment for Antenna Pin Voltage Based on the antenna class specification (3.1) of ISO/IEC14443, verify the maximum magnetic field strength (H max) according to the antenna class.

Some reader/writers may generate a magnetic field exceeding H max. In this case, the value is H max .

< Measurement example >

(1) Adjust the resonant capacitor value to set the resonant frequency to

13.56 MHz while the probe is connected to the node to be measured.

(2) Place the NFC tag on the center of the antenna.

(3) Change the output level of the signal generator to generate the

maximum magnetic field strength (H max) and measure the voltage

between VB and VSS pins using an oscilloscope.Revision History

No. Date Version Comment

1 Oct. 30, 201

2 1.00 Initial edition

2 Nov. 30, 2012 1.10 Added page 2.

Added communication distance data in table 1.

Modified antenna pin voltage data in table 2.

2 May 31, 2016 1.20 All pages: Change the example in MN63Y1213Request for your special attention and precautions

in using the technical information and semiconductors described in this book

(1)If any of the products or technical information described in this book is to be exported or provided to non-residents,the

laws and regulations of the exporting country,especially,those with regard to security export control,must be observed. (2)The technical information described in this book is intended only to show the main characteristics and application circuit

examples of the products.No license is granted in and to any intellectual property right or other right owned by Panasonic Corporation or any other company.Therefore,no responsibility is assumed by our company as to the infringement upon any such right owned by any other company which may arise as a result of the use of technical information de-scribed in this book.

(3)The products described in this book are intended to be used for general applications(such as office equipment,

communications equipment,measuring instruments and household appliances),or for specific applications as expressly stated in this book.

Please consult with our sales staff in advance for information on the following applications,moreover please exchange documents separately on terms of use etc.:Special applications(such as for in-vehicle equipment,airplanes,aerospace, automotive equipment,traffic signaling equipment,combustion equipment,medical equipment and safety devices)in which exceptional quality and reliability are required,or if the failure or malfunction of the products may directly jeopardize life or harm the human body.

Unless exchanging documents on terms of use etc.in advance,it is to be understood that our company shall not be held responsible for any damage incurred as a result of or in connection with your using the products described in this book for any special application.

(4)The products and product specifications described in this book are subject to change without notice for modification

and/or improvement.At the final stage of your design,purchasing,or use of the products,therefore,ask for the most up-to-date Product Standards in advance to make sure that the latest specifications satisfy your requirements.

(5)When designing your equipment,comply with the range of absolute maximum rating and the guaranteed operating

conditions(operating power supply voltage and operating environment etc.).Especially,please be careful not to exceed the range of absolute maximum rating on the transient state,such as power-on,power-off and mode-switching.Other-wise,we will not be liable for any defect which may arise later in your equipment.

Even when the products are used within the guaranteed values,take into the consideration of incidence of break down and failure mode,possible to occur to semiconductor products.Measures on the systems such as redundant design, arresting the spread of fire or preventing glitch are recommended in order to prevent physical injury,fire,social damages, for example,by using the products.

(6)Comply with the instructions for use in order to prevent breakdown and characteristics change due to external factors

(ESD,EOS,thermal stress and mechanical stress)at the time of handling,mounting or at customer's process.We do not guarantee quality for disassembled products or the product re-mounted after removing from the mounting board.

When using products for which damp-proof packing is required,satisfy the conditions,such as shelf life and the elapsed time since first opening the packages.

(7)When reselling products described in this book to other companies without our permission and receiving any claim of

request from the resale destination,please understand that customers will bear the burden.

(8)This book may be not reprinted or reproduced whether wholly or partially,without the prior written permission of our

company.

No.010618