1111111111111111 IIIIII IIIII 11111 1111111111 11111 1111111111 1111111111 111111111111111 11111111
`US 20050011961Al
`
`(19) United States
`(12) Patent Application Publication
`Uesaka
`
`(10) Pub. No.: US 2005/0011961 Al
`Jan. 20, 2005
`( 43) Pub. Date:
`
`(54) ANTENNA-COIL DESIGN APPARATUS AND
`DESIGN METHOD
`
`(76)
`
`Inventor: Kouichi Uesaka, Yokohama (JP)
`
`Correspondence Address:
`ANTONELLI, TERRY, STOUT & KRAUS,
`LLP
`1300 NORTH SEVENTEENTH STREET
`SUITE 1800
`ARLINGTON, VA 22209-9889 (US)
`
`(21) Appl. No.:
`
`10/890,320
`
`(22) Filed:
`
`Jul. 14, 2004
`
`(30)
`
`Foreign Application Priority Data
`
`Jul. 14, 2003
`
`(JP) ...................................... 2003-196179
`
`Publication Classification
`
`Int. CI.7 .................................................... G06K 19/06
`(51)
`(52) U.S. Cl. .............................................................. 235/492
`
`(57)
`
`ABSTRACT
`
`A method of designing on a short-time basis an antenna
`which satisfies desired electrical characteristic values.
`
`There is provided the method of designing the antenna coil
`used in a non-contact IC card or a RFID. Here, the antenna(cid:173)
`coil design method includes the following steps: Inputting
`information about plural configurations of the antenna coil
`and materials thereof, analyzing resistance, inductance, and
`stray capacitance of the antenna coil relative to the number
`of turns of the antenna coil in the inputted plural configu(cid:173)
`rations of the antenna coil, and, based on the analysis result,
`selecting one of the plural configurations of the antenna coil.
`
`ry
`
`, '
`-
`- J
`
`rx -
`
`Wy
`
`, '
`
`py
`
`,r
`
`-
`
`Wx --
`
`px
`
`-
`
`-
`
`•
`
`I.
`
`Lx
`
`SQUARE-FIGURED TYPE
`
`•
`
`Ly
`
`'
`
`.
`
`Petitioner Samsung and Google
`Ex-1024, 0001
`
`

`

`Patent Application Publication Jan. 20, 2005 Sheet 1 of 7
`
`US 2005/0011961 Al
`
`FIG. 1
`
`,----------CARD---------- ..
`
`,,-----READER/WRITER-----,
`/
`I
`,.--·R/W ANT.---,:
`,
`11
`I
`II
`:: k
`
`I
`
`I
`
`,--CARD ANT.--,
`:
`I
`:
`
`,.--- IC----
`I
`I
`-~.....;... ... :_~-~
`
`'
`
`'
`
`fl
`
`Rrw
`
`Crw
`
`I
`
`I
`I
`I
`I
`
`'---------- '=============;/
`
`/
`
`, _________ ,)
`\ , _____________ .,,,
`'--------------------------✓
`
`I
`I
`I
`
`rx _
`
`ry
`I
`
`.
`
`l
`
`Wx --
`-
`-
`
`px
`
`ill
`
`I.
`
`FIG. 2
`
`Wy
`
`. '
`
`py
`
`l f
`
`-
`
`Lx
`
`SQUARE-FIGURED TYPE
`
`I
`
`Ly
`
`,
`
`Petitioner Samsung and Google
`Ex-1024, 0002
`
`

`

`Patent Application Publication Jan. 20, 2005 Sheet 2 of 7
`
`US 2005/0011961 Al
`
`FIG. 3A
`
`FIG. 38
`
`FIG. 3C
`
`NUMBER OF TURNS- RESISTANCE: R
`~ 7 ~ SQUARECONFIGURATION.1 00~0 :ACTUALLY-MEASURED VALUES
`9..
`_. SQUARE CONFIGURATION. 2
`-g 6
`-.- ELLIPTIC CONRGURATION. 31----1----+--~~
`a:_ 5 ~ ELLIPTIC CONRGURATION. 4
`
`~4+ - - -~ - -~ -~~~ - - - - - l - - -~
`UJ
`U 3 ~ - - - - ~ ~ ~ ~ - ~ - - ~ - - - - l
`z
`~2r--~~~~~~...-c~--.J...._--~
`(J)
`m1+ -~~~~~~ - - -~ - - - - - l - - -~
`UJ
`a:o-~ .......... - .......... -~~ .......... -~-~~~-~
`5
`10
`15
`20
`25
`0
`NUMBER OF TURNS [N]
`
`~
`
`5: 30
`
`NUMBER OF TURNS - INDUCTANCE: L
`~ SQUARE CONFIGURATION. 1 00 ~ 0 : ACTUALLY-MEASURED VALUES
`_. SQUARE CONFIGURATION. 2
`-.- ELLIPTICCONRGURATION. 3 1 - - - - - 1 - - - - -+ -~ . r - . - 1
`::; 25
`0
`~ ELLIPTIC CONRGURATION. 4
`_J
`·20+----+-----+---1--~'--+---~
`~
`_J
`w15+----+-----+--1-=---1----+---~
`u
`~ 10-l------l----~~---~.J....~~~--~
`I-
`~ 5-t-----:h...-~IFr\;a,-, ..... ...._.)---+---~
`0
`z o-:t.....•~~~--.--1.-~~L~-L-~J
`5
`10
`15
`20
`25
`0
`NUMBER OF TURNS [N]
`
`NUMBER OF TURNS - CAPACITANCE: C
`CL 50 ~ SQUARE CONFIGURATION. 1 (cid:144) 0 ~ 0 : ACTUALLY-MEASURED VALUES
`'.;' 45 _. SQUARE CONFIGURATION. 2 1 - - - - - 1 - - - - - J . . - - - - - - 1
`-.- ELLIPTIC CONRGURATION. 3
`/-?. 40
`l - - - -+ - - - - ,A -+ - - - - - - 1
`~_ 35 -'JL-~•-E~LL~IPTl=C~CO~NR=GU=RA=TIO=N.~4---1---.==---+-------1
`~ 30 -+ - - - - - - l - - - - - - - 1 - - - -L - . .A . - - . J . . . . _ - _ _ _ J
`u
`w 25 -l-----+-----+--~~--~-----1
`~ 20 -l-------l-----l--..,t;..-.:;:.i:,._ __ ~-----1
`~15+-----+-------l'....-=,c__------,f---+-------1
`
`5 1 o t====;J;~~;:J:;;;;2~~~~~~~::~~-j
`
`~ 5-r
`~ 04--11 ...... rtj~~~~;.:...:;:.:i:...,._........., __ -1-.-.-.,.....,_j
`0
`5
`10
`15
`20
`0
`25
`NUMBER OF TURNS [N]
`
`Petitioner Samsung and Google
`Ex-1024, 0003
`
`

`

`Patent Application Publication Jan. 20, 2005 Sheet 3 of 7
`
`US 2005/0011961 Al
`
`FIG. 4A
`
`FIG. 48
`
`NUMBER OF TURNS - SELF-RESONANCE FREQUENCY: /c
`(cid:143) 6. 0: ACTUALLY-MEASURED VALUES
`SQUARE CONFIGUPA TION. 1 (cid:144)
`-
`~ 10000
`- - SQUARE CONFIGUPA TION. 2
`~
`-
`B.LIPTIC CONAGURATION. 3
`~
`- - B.LIPTIC CONAGURATION. 41-----------1
`~ 1000
`m
`:::,
`@
`a:
`LL w
`~ z
`@
`a:
`
`(.)
`
`10
`
`1 -+ - - , , - - - , -~ - - - , -~ - - . -~~ - - - r -~ -~ - - . - - - - - - - 1
`10
`15
`20
`25
`0
`5
`NUMBER OF TURNS [NJ
`
`14
`
`NUMBER OF TURNS - QUALITY FACTOR: Q
`-
`(cid:144) D 6. 0 :ACTUALLY-MEASURED VALUES
`SOUARECONFIGIJRATKlN.1
`- - SQUARE CON FIGURA TON. 2
`ELLIPTIC CO~IGUPATION.311-~~::;;::;.-..~t--.... 7
`-
`0 12
`-- ELLIPTICCOM=IGUPATION.4
`cc
`0 10 -j-1--..:::::...=..;-:ec..e..::.:::..:..:.:.:..:.:.::...:..J:~"""---+-----+------l
`I-
`(.)
`~ 8
`~ 6--t----,:..m---+----+-----+----l
`J 4--t----:-:.,,,._-+---+----+-----+----l
`<( 5 2 - - -~ - -+ - - - -+ - - - -+ - - - - -+ - - - - I
`0+---,---.-~.....+-.-~--.--1-,----,-.,..........-4-~-...----1--~----.-l
`5
`10
`15
`20
`25
`0
`NUMBER OF TURNS [NJ
`
`DISTANCE- COUPLING COEFFICIENT: k
`
`FIG. 4C
`
`.:.t:.
`
`I- 0.9
`z w 0.8
`0
`u. 0.7
`u. 0.6
`w
`0 0.5
`(.)
`CJ 0.4
`z 0.3
`J a.. 0.2
`:::> 0.1
`0
`(.) 0.0
`
`0
`
`2
`
`6
`4
`DISTANCE d [mm]
`
`8
`
`10
`
`Petitioner Samsung and Google
`Ex-1024, 0004
`
`

`

`Patent Application Publication Jan. 20, 2005 Sheet 4 of 7
`
`US 2005/0011961 Al
`
`[W/Ar18P] 131
`3A't:/M :Jl.13N8't:/V\1Otl.l:J373
`LO
`O
`LO
`O
`LO
`0
`LO
`0
`v
`v
`0
`0
`LO
`LO
`C\J
`C')
`(0
`C')
`C\J 0
`....---+--+--4-----1-........ -~ - 1 - - -~ 0
`0 ,....
`
`0
`0
`0 ,....
`
`E
`E
`........
`N
`"C
`
`~
`0 ~ oo
`,.... a:
`u.
`w
`0 z
`~ (/)
`
`0
`
`0 ,....
`
`,....
`
`LC) .
`(!J
`LL
`
`11
`
`I
`I
`
`I
`
`I
`
`I
`
`• • • •
`
`I
`
`•
`
`\
`
`LO
`O
`LO
`O
`LO
`O
`LO
`0
`~ ~ ~ ~ ~ M M C\J
`[A] A 38't:/.llOA 03:::>n0NI
`
`0
`C\J
`
`Petitioner Samsung and Google
`Ex-1024, 0005
`
`

`

`Patent Application Publication Jan. 20, 2005 Sheet 5 of 7
`
`US 2005/0011961 Al
`
`Petitioner Samsung and Google
`Ex-1024, 0006
`
`

`

`~ Spiral Antennas Simulator- [PARAMETER SETTING] Spiral-2
`FILE (F) TOOL (T) HELP (H)
`
`l!!l liJ ~
`
`FIG. 7
`
`ANTENNA CONFIGURATION
`
`GENERAL ITEM
`
`Type_A
`
`rx
`
`Lx
`
`========-;
`
`Type_B
`
`Lx
`
`MATERIAL PARAMETER
`I
`SELECTION OF SPIRAL CONFIGURATION DIAGRAM: 0 SQUARE CONFIGURATION O CIRCULAR CONFIGURATION
`ANTENNA NAME
`I Ant.1
`Ant.2
`I I Ant.3 I~
`1 I TU RN
`1
`TURN START/SURFACE NUMBER OF TURNS
`I
`1 11
`1
`24
`TURNFINISH/REAR-SURFACENUMBEROFTURNSI
`1511
`20
`15ITURNS
`56.60
`x-DIRECTIONOUTERSIZE~x)
`I 80.00
`80.0011
`:===:::::
`~ 46.40
`y-DIRECTIONOUTERSIZE~y)
`J 50.00
`50.00 II
`:===:::::
`0.50)[mm]
`~
`x-DIRECTION WIRING WIDTH (Wx)
`0.5011
`0.501
`0.50 L - - . . . , , -~
`y-DIRECTION WIRING WIDTH (Wy)
`0.501 [mm]
`0.50 .------o.sQ]J
`a.sol
`-~ ~-' -
`x-DIRECTION WIRING PITCH (Px)
`1.00.
`1.soil
`1.00 I
`1.501 [mm]
`:::==:=:
`y-0IRECTION WIRING PITCH (Py)
`1.50 [mm]
`1.50
`1.00II
`1.00
`I
`LINE THICKNESS (I)
`36.00 [um]
`J 36.00II
`36.00
`36.00
`28.05 [mm]
`CORNER RADIUS (rx)
`I
`0.00 II
`0.00
`28.05
`CORNER RADIUS (fy)
`22.95 [mm]
`I
`0.00 II
`0.00
`22.95
`2.47 [µ Q. cm]
`WIRING RESISTIVITY
`I
`2.4711
`2.47
`2.47
`0.00 I I
`ROTATION ANGLE -0
`30.00 [deg]
`I
`0.00
`30.00
`CONFIGURATION TYPE
`81
`JB
`811B
`811B
`8IJB
`LAYER STRUCTURE
`11 LAYER8ll 1 LAYER8l11 LAYER8ll 1 LAYER81
`I ACCURACY 811 ACCURACY 811 ACCURACY 811 ACCURACY 81 I UPDATE I
`PRIORITY ITEM
`
`EXTRACTION WIRING
`
`I
`
`'I
`
`I
`
`""C
`
`~ .... ~ = ....
`~ "Cl -....
`~ ....
`.... 0 =
`~
`O' -....
`~ ....
`.... 0 =
`
`(')
`
`(')
`
`~
`~
`?
`N ~=
`
`N
`0
`0
`Ul
`
`'JJ. =(cid:173)~
`~ ....
`0 ....,
`-..J
`
`O'I
`
`d
`'JJ.
`N
`0
`0
`~
`0
`0
`'"""
`'""" \0
`'""" >
`'"""
`
`O'I
`
`Petitioner Samsung and Google
`Ex-1024, 0007
`
`

`

`Patent Application Publication Jan. 20, 2005 Sheet 7 of 7
`
`US 2005/0011961 Al
`
`FIG. 8
`
`ELECTRICAL
`CHARACTERISTICS
`
`NOTATION
`
`ANTENNA ELEMENTS MAKING
`SIGNIFICANT CONTRIBUTIONS TO
`ELECTRICAL CHARACTERISTICS
`
`RESISTANCE R
`
`Rrw, Red
`
`WIRING CROSS-SECTION
`CONFIGURATION, MATERIAL
`
`INDUCTANCE L
`
`Lrw, Led
`
`WIRING CONFIGURATION
`
`STRAY
`CAPACITANCE C
`
`Crw, Ced
`
`WIRING CONFIGURATION,
`MATERIAL
`
`COMMUNICATIONS
`DISTANCE
`
`COUPLING
`COEFFICIENT
`
`RESONANCE
`FREQUENCY
`
`COMMUNICATIONS
`BANDWIDTH
`
`d
`
`k
`
`fe
`
`Q
`
`WIRING CONFIGURATION
`
`L,d
`
`L,C
`
`R,L,C
`
`FIG. 9
`
`ELLIPTIC
`ELLIPTIC
`SQUARE
`CONFIGURATION SQUARE
`CONFIGURATION 1 CONFIGURATION 2 CONFIGURATION 3 CONFIGURATION 4
`
`OUTER-
`CONFIGURATION
`L(mm)
`LINEWIDTH
`w(mm)
`
`PITCHp(mm)
`
`80.0X50.0
`
`57.0X46.0
`
`0.5
`
`1.0
`
`1.5
`
`1.0
`
`1.5
`
`LINE THICKNESS
`t(µm)
`
`36.0
`
`Petitioner Samsung and Google
`Ex-1024, 0008
`
`

`

`US 2005/0011961 Al
`
`Jan.20,2005
`
`1
`
`ANTENNA-COIL DESIGN APPARATUS AND
`DESIGN METHOD
`
`CROSS-REFERENCE TO RELATED
`APPLICATION
`[0001] The disclosure of Japanese Patent Application No.
`JP2003-196179 filed on Jul. 14, 2003 including the speci(cid:173)
`fication, drawings and abstract is incorporated herein by
`reference in its entirety.
`
`BACKGROUND OF THE INVENTION
`
`[0002] The present invention relates to a design method
`and design apparatus for designing an antenna coil used in
`a non-contact IC card or a RFID.
`[0003]
`In the non-contact IC card, the RFID, or the like
`(which, hereinafter, will be referred to as "IC card or the
`like"), an electromagnetic field (magnetic field) radiated by
`a reader/writer unit (hereinafter, referred to as "R/W") is
`received by an antenna formed on the IC card or the like.
`Then, the electromagnetic field (magnetic field) received is
`converted into electric power so as to drive the IC. Also,
`communications from the R/W to the IC card or the like are
`performed using signal components contained in modulation
`or the like of the electromagnetic field (more essentially
`magnetic field in this case) radiated by the R/W. Moreover,
`in communications from the IC card or the like to the R/W,
`the signal transmissions to the R/W are performed by load
`modulation or the like.
`[0004] At this time, the electric power which is receivable
`by the IC card or the like is determined based on the self
`inductances, mutual inductance, and coupling coefficient of
`the antenna formed on the IC card or the like and an antenna
`formed on the R/W. Furthermore, it is required that the
`electric power which is supplyable to the R/W antenna be
`suppressed within a range in which the electric field radiated
`from the R/W antenna satisfies the regulations by the Radio
`Law or the like.
`[0005] This requirement determines an upper-limit of the
`electric power supplyable to the R/W antenna. In addition,
`the electric power to be received is determined from a
`transmission efficiency of the electric power to the IC card
`or the like. As a result, the communications area is deter(cid:173)
`mined.
`[0006] Accordingly, it is required that electrical elements
`of the coil antenna to be formed on the IC card or the like,
`e.g., the antenna's inductance, resistance, and capacitance,
`be designed while satisfying various conditions by consid(cid:173)
`ering the coil antenna itself and its relationship with the
`R/W.
`[0007] Meanwhile, as antenna design technologies and
`analysis technologies for the antenna design, there exist such
`methods as the moment method and finite-element method.
`These techniques, however, are the following methods:
`Configuration data on an antenna is inputted first, and then
`respective types of set conditions (i.e., boundary conditions
`and so on) are set for this configuration, and after that, the
`analysis is performed. A conventional antenna design
`method has been disclosed in, e.g., JP-A-7-22976. This
`conventional method is as follows: With respect to a fre(cid:173)
`quency range necessary for the antenna design, frequency
`characteristics of respective elements of an impedance
`
`matrix in the moment method are stored into a memory in
`advance. This in-advance storage allows a significant reduc(cid:173)
`tion in the computation time necessary for the antenna
`design.
`
`SUMMARY OF THE INVENTION
`
`[0008]
`In the conventional techniques, the antenna con(cid:173)
`figuration is determined at first, and after that, the antenna's
`electrical characteristic values for the time or frequency are
`computed. Consequently, if, after the determination of the
`antenna configuration, the computed antenna's electrical
`characteristic values for the time or frequency have failed to
`satisfy predefined values, it becomes required to determine
`a new antenna configuration once again. Namely, there has
`existed a problem of being incapable of effectively reducing
`the time for the antenna design.
`[0009] The present invention has been devised in order to
`solve the above-described problem. Namely, an object of the
`present invention is to design, on a short-time basis, an
`antenna which satisfies preset electrical characteristic values
`without the necessity for redesigning configuration of the
`antenna many times in accordance with the analysis result of
`the electrical characteristics or the like.
`[0010]
`In the present invention, a frequency to be used for
`the IC card or the like is determined at first. After that, the
`antenna's electrical characteristic values for configuration of
`the antenna on the IC card or the like are computed. Also,
`when computing and displaying the electrical characteristic
`values for a predetermined frequency, e.g., relationship
`between the antenna's number of turns and resistance value,
`the display is performed in such a manner that a comparison
`is made among the results computed for each antenna
`configuration prepared in advance.
`[0011] Other objects, features and advantages of the
`invention will become apparent from the following descrip(cid:173)
`tion of the embodiments of the invention taken in conjunc(cid:173)
`tion with the accompanying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0012] FIG. 1 illustrates an equivalent circuit of a non(cid:173)
`contact IC card and a R/W;
`[0013] FIG. 2 illustrates an example of input parameters
`of square-figured and ellipse-figured spiral antennas;
`[0014] FIGS. 3A to 3C illustrate an example of analysis
`result of the antenna according to the present application;
`[0015] FIGS. 4A to 4C illustrate an example of analysis
`result of the antenna according to the present application;
`[0016] FIG. 5 illustrates an example of analysis result of
`the antenna according to the present application;
`[0017] FIG. 6 illustrates an example of analysis result of
`the antenna according to the present application;
`[0018] FIG. 7 illustrates an example of input parameters
`for square-figured and ellipse-figured spiral antennas;
`[0019] FIG. 8 is a table for illustrating electrical charac(cid:173)
`teristics of the IC-card antenna and those of the R/W
`antenna; and
`[0020] FIG. 9 is a table for summarizing antenna configu(cid:173)
`rations in the respective embodiments of the IC card.
`
`Petitioner Samsung and Google
`Ex-1024, 0009
`
`

`

`US 2005/0011961 Al
`
`Jan.20,2005
`
`2
`
`DETAILED DESCRIPTION OF IBE
`INVENTION
`[0021] Referring to the drawings, the explanation will be
`given below concerning embodiments of the present inven(cid:173)
`tion. Incidentally, it is needless to say that, although the
`explanation will be given below regarding a non-contact IC
`card, the explanation is also applicable to the design and
`analysis of such antennas as a RFID.
`[0022] First, electrical elements will be investigated which
`become important between the non-contact IC card or the
`like and a reader/writer unit (:R/W) in the case of designing
`the non-contact IC card or the like.
`[0023] FIG. 1 illustrates an equivalent circuit of the R/W
`and the IC card. In this equivalent circuit, the R/W includes
`circuit impedance R0 , resonance capacitance C0 , inductance
`L,w of a R/W antenna, resistance R,w, and capacitance C,w·
`Here, resonance frequency of the R/W is determined as
`being equal to carrier-wave frequency, or frequency which
`exceeds the carrier-wave frequency. Next, the IC card
`includes inductance Led of a card antenna, resistance Red•
`capacitance Ced• capacitance Cic which an IC to be mounted
`thereon exhibits, and resistance Ric which is equivalent to
`the electric power consumed.
`[0024] Here, resonance frequency of the IC card is also
`determined as being equal to the carrier-wave frequency, or
`the frequency which exceeds the carrier-wave frequency.
`Moreover, coupling coefficient k, which means coupling
`between the R/W and the IC card, is set simultaneously,
`thereby forming the entire equivalent circuit. In the above(cid:173)
`described equivalent circuit, power supply VO is determined
`from R/W-antenna electric power which satisfies the regu(cid:173)
`lations by the Radio Law or the like.
`[0025] From this situation, it becomes required to deter(cid:173)
`mine L,w, C,w, co, Led• Ced• and cic which maximize
`electric-power transmission efficiency, and the coupling
`coefficient k which is to be determined by position relation(cid:173)
`ship between the R/W and the IC card. Also, from the
`it becomes
`objective of performing communications,
`required to determine communications bandwidth so that
`sub carrier wave can be transmitted enough. This commu(cid:173)
`nications bandwidth is determined by R,w, L,w, C,w, C0
`, Red•
`Led• Ced• cic• and Ric• and the coupling coefficient k.
`[0026] Here, it is true that the electrical characteristic
`values of the antennas depend on the used frequency to a
`certain extent. Basically, however, the characteristic values
`are determined by configuration or material of the antennas.
`Concretely, the details are just what are explained in FIG. 8.
`[0027] Subsequently, the explanation will be given below
`concerning the electrical characteristics explained above,
`and an antenna design method using antenna elements (i.e.,
`wiring configuration, material, and the like) which make
`significant contributions to the electrical characteristics. As
`described earlier, the conventional antenna design method is
`as follows: The antenna configuration is determined and
`inputted at first, and then the antenna elements, which
`become foundation of the respective types of electrical
`characteristic parameters, are determined and inputted.
`Next, the electromagnetic-field analysis is performed, and
`then the analysis result is displayed. Furthermore, if the
`analysis result has failed to satisfy the predetermined con(cid:173)
`ditions, the antenna configuration is considered and inputted
`once again.
`
`[0028] On the other hand, in the application according to
`the present invention, parameters of plural different antenna(cid:173)
`coil configurations prepared in advance are inputted. Here,
`the plural antenna configurations are selected, and the
`parameters having a predetermined range are inputted. FIG.
`2 illustrates an example of the analysis method and the input
`parameters of square-figured and ellipse-figured spiral
`antennas. In the case of the square-figured spiral antenna, the
`configuration is set for antenna parameters, i.e., outer(cid:173)
`configuration size L,_, Ly, line width wx, wy, pitch Px, Py, line
`thickness t, and corner radius rx, ry- Similarly, in the case of
`the ellipse-figured spiral antenna, the configuration is set for
`antenna parameters, i.e., outer-configuration size Lx, Ly, line
`width wx, wy, pitch Px, Py, line thickness t, and radius
`rx(=(Lx-wx)/2), ry(=(Ly-wy)/2). In the present embodiment,
`the following parameters have been inputted as an example:
`
`[0029]
`In this case, by selecting the number N of turns of
`an antenna as a parameter, it is possible to determine the
`respective types of electrical characteristic values ( e.g.,
`resistance R, inductance L, and capacitance C) of the
`antenna.
`
`[0030] FIGS. 3A to 3C, with respect to the above-de(cid:173)
`scribed input parameter, illustrate relationship between the
`turn-number of the antenna and the resistance R thereof
`(FIG. 3A), relationship between the turn-number of the
`antenna and the inductance L thereof (FIG. 3B), and rela(cid:173)
`tionship between the turn-number of the antenna and the
`stray capacitance C thereof (FIG. 3C). FIGS. 3A to 3C
`indicate the following results: Concerning the resistance R,
`since the turn-number of the spiral configuration is defined
`from the outer circumference, an increase in the line-path
`length becomes smaller as the turn-number increases. This
`results in saturation of an increase in the resistance R in
`accompaniment with the increase in the turn-number. Also,
`regarding the inductance L, as the turn-number increases,
`the self inductance increases in response to the line-path
`length, and also mutual inductance between the line paths
`increases. This allows the inductance L to exhibit an S-char(cid:173)
`acter-like characteristic. Also, the stray capacitance C (i.e.,
`parasite capacitance) increases in accompaniment with the
`increase in the turn-number.
`
`[0031]
`Incidentally, the antenna outer-configuration (i.e.,
`length of the outermost circumference) and the antenna's
`pitch have been inputted. This makes it possible to deter(cid:173)
`mine upper-limit of the turn-number of the antenna.
`
`[0032] Here, the electrical characteristics of the antenna
`will be investigated. The increase in the resistance R means
`that a loss in the antenna increases, which is not an advisable
`policy from the standpoint of the electric-power transmis(cid:173)
`sion. The increase in the inductance L, however, is desirable,
`because the increase in the inductance increases the electric(cid:173)
`power transmission efficiency. Also, as regards the stray
`capacitance (i.e., parasite capacitance), considering that the
`antennas are made resonant with each other at a used
`frequency (i.e., carrier-wave frequency), the increase in the
`stray capacitance (i.e., parasite capacitance) is desirable. The
`reason for this is as follows: For the purpose of earning
`capacitance needed at the frequency with respect to the
`inductance, as this capacitance gets larger, the capacitance
`C to be mounted within the IC gets smaller. This means that
`th~ resultant chip area becomes smaller, which is desirable.
`If, however, the resonance frequency grows lower than the
`
`Petitioner Samsung and Google
`Ex-1024, 0010
`
`

`

`US 2005/0011961 Al
`
`Jan.20,2005
`
`3
`
`carrier-wave frequency, it becomes impossible to optimize
`the electric-power transmission efficiency. This brings about
`a disadvantage, although the capacitance within the IC is
`unnecessary. This whole situation indicates that, depending
`on a used protocol or the like, there exist optimum values for
`the resistance R, inductance L, and capacitance C of the
`antenna.
`
`[0033]
`In order to determine these optimum values, the
`further investigation needs to be performed concerning
`self-resonance frequency fc and quality Q of the inductance
`L from the resistance R, inductance L, and capacitance C of
`the antenna. Here, Q denotes "Quality Factor", which means
`quality of the configuration components L, C, and the like,
`i.e., essential attribute of L which is specific to L, essential
`attribute of C which is specific to C, and the like.
`
`[0034] FIGS. 4A to 4C illustrate the results which, using
`the resistance R, inductance L, and capacitance C of the
`antenna computed above, are acquired by computing rela(cid:173)
`tionship between the turn-number of the antenna and the
`self-resonance frequency fc thereof (FIG. 4A), and relation(cid:173)
`ship between the turn-number of the antenna and the quality
`as the inductance thereof or Q containing the IC (FIG. 4B).
`Incidentally, in the simulation of the present embodiment,
`the bandwidth BW of the sub carrier wave is equal to (847.5
`kHzx2) in the case where the carrier-wave frequency and
`transmission rate are set as 13.56 MHz and 211.875 k
`respectively.
`
`[0035] On account of this, the self-resonance frequency fc
`needs to be higher than 13.56 MHz. On account of this, the
`turn-number needs to be smaller than 11 to 15. Also, the chip
`area makes it possible to determine upper-limit of the
`capacitance Cic which is mountable within the IC. If the
`upper-limit falls within, e.g., 50 pF, judging from Cic=l/
`((2itfcr 2xLcd)-Ccd• the turn-number needs to be larger than
`5 here. Also, since the necessary communications band
`satisfies Q<13.56 MHz/(847.5 kHzx2)=8, the turn-number
`needs to be smaller than 7 to 10.
`
`[0036] Summarizing the above-described conditions indi(cid:173)
`cates that the optimum turn-number range turns out to be 5
`to 7.
`
`[0037] Moreover, FIG. 4C illustrates the result acquired
`by computing relationship between the distance and the
`coupling coefficient between the non-contact IC card or the
`like and the reader/writer unit (:R/W). This coupling coef(cid:173)
`ficient exerts tremendous influences on the electric-power
`transmission efficiency. Namely, the larger this value gets,
`the better the efficiency becomes.
`
`[0038]
`In the present embodiment, from the above-de(cid:173)
`scribed relationship between the antenna turn-number and
`the self-resonance frequency fc (FIG. 4A), and relationship
`between the antenna turn-number and the Q value (FIG.
`4B), it has been recognized that the antenna turn-number
`smaller than 7 is desirable. Consequently, the turn-number 6
`has been selected as target turn-number by taking the margin
`into consideration.
`
`[0039] The distance characteristic of the coupling coeffi(cid:173)
`cient k is determined regarding a case of two square-figured
`spiral antennas having different pitches, and a case of a
`square-figured spiral antenna and an ellipse-figured spiral
`antenna.
`
`[0040] Here, in the case of the two square-figured spiral
`antennas, it is true that the value of the coupling coefficient
`is large. Causing the IC to operate at the maximum value,
`however, makes the operation impossible at a location where
`the coupling coefficient is small. On the other hand, the
`operation is made possible at the location where the cou(cid:173)
`pling coefficient is small. This operation causes an induced
`voltage to exceed the withstand voltage of the IC at a
`location where the coupling coefficient is large, thus becom(cid:173)
`ing the cause of a failure. On account of this, in the case of
`wishing to enlarge the communications area, the combina(cid:173)
`tion of the square-figured spiral antenna and the ellipse(cid:173)
`figured spiral antenna is desirable where a variation li.k in the
`coupling coefficient is small.
`
`[0041] Finally, FIG. 5 illustrates the result acquired by
`analyzing the electromagnetic field ( electric field or mag(cid:173)
`netic field) radiated from the antenna. Here, the value is
`illustrated which can be considered to be converted into the
`electric-field strength from a voltage value in the case where
`the electric-field strength or magnetic-field strength with
`respect to the distance from the spiral antenna is received by
`a loop antenna stipulated by the regulations.
`
`[0042] The upper-limit of the electric power which is
`supplyable to the R/W antenna becomes a value which
`satisfies the Radio-Law regulation value (i.e., 54 dBDV/
`m@3 m). In the present application, further, the electric
`power acquired by taking into consideration the margin 6 dB
`to the Radio-Law regulation value is supplied to the R/W.
`
`[0043] FIG. 5 simultaneously illustrates computation
`result of the voltage (i.e., voltage to be received) induced at
`an IC-end portion on the IC-card side when this electric
`power is supplied to the R/W antenna. As a result of this, in
`the system of this antenna and the IC, the voltage attains to,
`e.g., the maximum voltage 5.35 V when the distance
`between the R/W and the IC card is equal to 2 mm. This
`shows that the IC withstand voltage is satisfied. Also, the
`IC-operating voltage 3V is satisfied up to the inter-R/W-card
`distance which is close to 20 mm. Accordingly, this distance
`turns out to be the limit of the communications distance.
`
`[0044] As having been explained so far, by employing the
`design method and design apparatus of the present invention
`for designing the antenna coil used in the non-contact IC
`card or the like, it becomes possible to input such input
`parameters as the antenna configurations which have a
`predetermined
`range. This characteristic, accordingly,
`allows the resistance R, inductance L, and capacitance C of
`the antenna to be computed without specifying the antenna
`configurations as a single antenna configuration from the
`beginning. This computation, further, allows the determina(cid:173)
`tion of the self-resonance frequency fc and the Q value of the
`antenna, which, namely, are computed by using the com(cid:173)
`puted resistance R, inductance L, and capacitance C.
`
`[0045] Moreover,
`frequency of each
`resonance
`the
`antenna can be determined from the R/W and the capaci(cid:173)
`tance Cic mounted within the IC, and the Q value can be
`determined from the load resistance. Namely, making a
`comparison among these computation results makes it pos(cid:173)
`sible to design (i.e., specify) the optimum antenna configu(cid:173)
`ration in a final manner.
`
`[0046]
`Incidentally, when designing the optimum antenna
`configuration, it is possible to take into consideration proxi-
`
`Petitioner Samsung and Google
`Ex-1024, 0011
`
`

`

`US 2005/0011961 Al
`
`Jan.20,2005
`
`4
`
`mate/remote electric-field/magnetic-field analysis results,
`and also to set the antenna-supplied electric power. Further(cid:173)
`more, the analysis based on the equivalent circuit also allows
`the analysis of the electric-power transmission and commu(cid:173)
`nications.
`
`[0047]
`In the above-described description, the explanation
`has been given concerning the optimum antenna-configura(cid:173)
`tion design. As illustrated in FIG. 6, however, the present
`analysis method and apparatus allow presentation of a result
`which is computed as to how the magnetic-field distribution
`will change when the non-contact IC card having the
`antenna configuration determined above has passed over the
`reader/writer unit.
`
`[0048]
`Incidentally, in the above-described description,
`the outer-configuration, line width, pitch, and line thickness
`have been presented as the antenna-configuration informa(cid:173)
`tion to be inputted. As illustrated in FIG. 7, however, it is
`possible to input a variety of antenna configurations in such
`a manner that the antenna configurations are made to have
`predetermined widths.
`
`[0049]
`It becomes possible to design, on a short-time
`basis, the antenna which satisfies desired electrical charac(cid:173)
`teristic values without the necessity for redesigning the
`antenna configuration many times in accordance with the
`analysis result of the electrical characteristics or the like.
`
`[0050]
`It should be further understood by those skilled in
`the art that although the foregoing description has been
`made on embodiments of the invention, the invention is not
`limited thereto and various changes and modifications may
`be made without departing from the spirit of the invention
`and the scope of the appended claims.
`
`1. A method of designing an antenna coil used in a
`non-contact IC card or a RFID, comprising the steps of:
`
`inputting information about plural configurations of an
`antenna coil and materials thereof,
`analyzing resistance, inductance, and stray capacitance of
`said antenna coil relative to number of turns of said
`antenna coil in said inputted plural configurations of
`said antenna coil, and, based on said analysis result,
`selecting one of said plural configurations of said antenna
`coil.
`2. The antenna-coil design method according to claim 1,
`further comprising a step of
`taking advantage of said analyzed resistance, inductance,
`and stray capacitance of said antenna coil thereby to
`analyze self-resonance frequency of said antenna coil
`relative to said number of turns of said antenna coil.
`3. The antenna-coil design method according to claim 1 or
`2, further comprising a step of
`taking advantage of said analyzed resistance, inductance,
`and stray capacitance of said antenna coil thereby to
`analyze coupling coefficient relative to distance,
`
`said coupling coefficient being established between said
`antenna coil used in said non-contact IC card or said
`RFID and an antenna coil of a reader/writer,
`said distance being measured between said antenna coil
`used in said non-contact IC card or said RFID and said
`antenna coil o