Published Patent 10-2013-0000926
`
` (19) Korean Intellectual Property Office (KR)
`(12) Published Patent Publication (A)
`(51)
`International Patent Classification (Int. Cl.)
`
`H01Q 7/00 (2006.01) H02J 17/00 (2006.01)
`
`H01F 5/00 (2006.01)
`
`(21)
`Application No.
`
`(22)
`Application date
`Examination request date
`
`10-2011-0061746
`June 24, 2011
`June 24, 2011
`
`(11) Publication No.
`(43) Publication Date
`
`10-2013-0000926
`January 3, 2013
`
`(71)
`
`
`
`(72)
`
`Applicant
`YU, Hyun-Soo
`236-411 (Sinmae Taeseong Mansion, Sinmae-dong), 50,
`Gosan-ro, Suseong-gu, Daegu
`Inventor
`YU, Hyun-Soo
`236-411 (Sinmae Taeseong Mansion, Sinmae-dong), 50,
`Gosan-ro, Suseong-gu, Daegu
`
`
`Total number of claims: Total of 7 claims
`
`(54) Title of Invention MOUNTING APPARATUS FOR NEAR FIELD COMMUNICATION (NFC) ANTENNA AND
`COIL FOR TRANSMITTING POWER FOR WIRELESS CHARGING
`(57) Abstract
`
`An invention design having a wireless power transmission function capable of wireless charging within the size of the area for
`mounting a near field communication (NFC near field communication, hereinafter referred to as near field communication)
`antenna.
`
`It devises a design of a coil for transmitting power for wireless charging without degradation of the performance of the near
`field communication antenna and a design and arrangement structure of a near field communication antenna to ensure there is
`no loss in power transmission and provides an integrated mounting structure in a single element.
`
`Keywords include near field communication (NFC), antenna, wireless charging, wireless power transmission coil, miniaturized
`design of a wireless power transmission coil, and integrated mounting structure for a near field communication antenna and
`wireless charging.
`
`
`
`Representative figure – Fig. 6
`
`An embodiment in which a small coil for wireless charging is mounted inside a near field communication
`(NFC) antenna
`
`Coil for transmitting power
`for wireless charging
`
`Gap: 3 mm
`
`Near field communication
`antenna
`
`
`
`
`
`
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`Page 1 of 43
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`SAMSUNG EXHIBIT 1026
`
`

`

`Published Patent 10-2013-0000926
`
`Scope of claims
`
`Claim 1
`
`An apparatus for mounting a coil for wireless power transmission inside the space comprising a near field communication
`antenna and an apparatus for mounting a near field communication antenna inside the space comprising a coil for transmitting
`power
`
`for reducing the space for mounting parts.
`
`Claim 2
`
`The apparatus of claim 1,
`
`wherein the apparatus mounts a plurality of one or more of the power transmission coils in a space comprising the near field
`communication antenna using the power transmission coil by using a frequency of 300 khz to 50 Mhz such that it is possible
`to miniaturize the power transmission coil for wireless charging to mount the power transmission coil for wireless charging in
`the area inside the near field communication antenna.
`
`Claim 3
`
`The apparatus of claim 1,
`
`wherein the apparatus mounts the near field communication antenna and the coil for transmitting power on a single board
`element,
`
`wherein the apparatus relates to the material of the board element and the formation of the near field communication antenna
`and the coil, and
`
`mounts the near field communication antenna and the coil for transmitting power by forming a pattern with a copper layer
`(copper: copper thin film) by using a PCB for FPCB as the board material,
`
`wherein the apparatus uses a thin PC (polycarbonate) sheet (a thin sheet like a film) as the board material and mounts the near
`field communication antenna and the coil for transmitting power with a copper wire coated with enamel on top of this sheet.
`
`Claim 4
`
`The apparatus of claim 1,
`
`wherein the apparatus mounts the coil for transmitting power and the near field communication antenna by placing them on a
`single board on top of a single electromagnetic wave absorber inserted between the near field communication antenna and the
`battery,
`
`in a method for mounting on a battery as a method for mounting inside a portable device.
`
`Claim 5
`
`The apparatus of claim 1,
`
`wherein the apparatus mounts the near field communication antenna and the coil for transmitting power by placing them on a
`single board on top of a single electromagnetic wave absorber on top of a metallic material such as a shield can, as another
`method for mounting inside a portable device.
`
`Claim 6
`
`The apparatus of claim 1,
`
`wherein the gap between the near field communication antenna and the power transmission coil for transmitting power of 3 W
`to 20 W is formed to be 3.0 mm to 9 mm.
`
`Claim 7
`
`The apparatus of claim 3,
`
`wherein the apparatus mounts the near field communication antenna and the power transmission coil by laminating the
`formation of a copper foil pattern in several layers on top of a single board using a PCB or FPCB material.
`
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`Published Patent 10-2013-0000926
`
`Specification
`
`Technical field
`
`[0001] The present invention relates to a design of a coil for wireless power transmission, and more particularly, to reducing
`the mounting area by manufacturing a near field communication antenna and a coil for transmitting power in the same space
`and manufacturing without degradation of mutual performance between the NFC (near field communication) antenna used for
`near field communication and the coil for wireless power transmission.
`
`
`
`Background art
`
`[0002] Recently, the introduction of wireless charging function and the usability of near field communication are increasing
`in prominence in mobile portable devices, specifically mobile phones, and near field communication and a coil for wireless
`power transmission for wireless charging need to be used at the same time.
`
`[0003] The method currently being used mounts the near field communication antenna on top of the battery cover or battery,
`and the wireless charging power transmission coil is used by attaching a separate case to the outside of the portable device.
`
`[0004] In other words, the near field communication antenna is mounted inside the portable device and the coil for transmitting
`power for wireless charging is mounted outside of the portable device, which are mounted separately as two parts, and since
`they also occupy the mounting area separately, a large mounting space is required.
`
`[0005] It is difficult to provide mounting space for a power transmission coil for wireless charging in a portable device
`attempting to equip a wireless charging function, which is a new function.
`
`[0006] Also, the coil for transmitting power for wireless charging that is currently being used transmits power at a low
`frequency of 100 khz to 130 khz, therefore the size of the coil for transmitting power is large.
`
`
`
`Details of invention
`
`Problem to be solved
`
`[0007] Recently, portable devices using the wireless charging method that emphasize the convenience of charging are being
`introduced in the market, but there is difficulty in securing a mounting space for the inductive coil for wireless charging devices
`in miniaturized portable devices.
`
`[0008] The problem in the prior art is that there is difficulty in securing a space for mounting two elements (a power
`transmission coil for wireless charging and a near field communication antenna) simultaneously in a mobile device because
`there needs to be an area to mount an inductive secondary coil for wireless charging inside the portable device and there must
`be a separate area for mounting a near field communication antenna.
`
`[0009] An object of the present invention is in reducing the size of components of the power transmission coil for wireless
`charging and the near field communication antenna such that they can be mounted in a small space in a portable device.
`
`
`
`Means for solving the problem
`
`[0010] To achieve said object, the present inventor mounted a coil for wireless power transmission inside the space comprising
`the near field communication antenna, or it was made to mount a near field communication antenna inside the space comprising
`the coil for power transmission.
`
`[0011] To mount the wireless charging power transmission coil inside the space comprising the near field communication
`antenna, a power transmission coil was manufactured using a frequency of 300 khz to 50 Mhz to be able to miniaturize the
`power transmission coil for wireless charging, and the power transmission coil was mounted inside the space comprising the
`near field communication antenna.
`
`[0012] As a method for further reducing the component mounting, a device for mounting the near field communication antenna
`and the power transmission coil on top of a single board using a PCB or FPCB material by laminating the formation of a
`copper foil pattern in several layers was used.
`
`[0013] To manufacture a single integrated component, the near field communication antenna and the coil for transmitting power were mounted
`on a single board element, and the material of the board element and the formation of the near field communication antenna and the coil are
`as follows. The near field communication antenna and the coil for transmitting power were mounted by forming a pattern with a copper layer
`
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`Published Patent 10-2013-0000926
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`(copper: copper thin film) by using a PCB for FPCB as the board material and, as another method, a device using a thin PC (polycarbonate)
`sheet (a thin sheet like a film) as the board material and mounting the near field communication antenna and the coil for transmitting power
`with a copper wire coated with enamel on top of this sheet was implemented.
`
`[0014] As a method for mounting in a portable device, with the near field communication antenna, it was mounted by placing the coil for
`power transmission and the antenna on top of a single electromagnetic wave absorber on top of the battery, or it was mounted by placing the
`near field communication antenna and the coil for power transmission on top of a single board on top of a single electromagnetic wave absorber
`on top of a metallic material such as a shield can.
`
`[0015] To prevent performance degradation caused by mutual interference between the near field communication antenna and the coil for
`power transmission, the gap between the near field communication antenna and the power transmission coil for transmitting power of 3 W to
`20 W was formed to be 3.0 mm to 9 mm.
`
`Effect of invention
`
`[0016] According to the method of the present invention, the space for mounting a near field communication antenna and a power transmission
`coil was manufactured to be small, and there is an advantage in that a power transmission coil can be mounted together at the size of a near
`field communication antenna.
`
`[0017] In addition, the present invention, which allows the near field communication antenna and the power transmission coil to be made
`smaller, allows the mounting to be possible in a smaller area than the current size of near field communication antennas.
`
`[0018] Even in terms of cost, it reduced the number of components and provided cost reduction by manufacturing a near field communication
`antenna and a power transmission coil on top of a single board.
`
`Brief description of figures
`
`[0019] Fig 1 is a block diagram of the pattern of the coil for transmitting power for wireless charging used in a method of the prior art
`
`Fig 2 is a block diagram of the pattern of a near field communication antenna (NFC antenna) used in the prior art
`
`Fig 3 is an embodiment of a miniaturization design of the coil for transmitting power for wireless charging applied to the present invention
`
`Fig 4 is a diagram of the distribution pattern of a current flowing in a conducting wire and an electromagnetic field distributed around the conducting
`wire
`
`Fig 5 is a diagram of the effect of degrading reception on the near field communication antenna according to the distance between the near field
`communication antenna and the coil for power transmission
`
`Fig 6 is an embodiment in which the near field communication (NFC) antenna and the coil for wireless charging to which the present invention is
`applied are manufactured in small sizes
`
`Fig 7 is a block diagram of a correlation test for an antenna performance degradation test according to the gap length between the near field
`communication antenna and the coil for transmitting power applied to the present invention
`
`Fig 8 is a block diagram of the wireless charger applied to the present invention, a diagram for wireless power transmission test, and the test result
`
`Fig 9 is an embodiment in which a coil for wireless charging is mounted inside the near field communication (NFC) antenna applied to the present
`invention
`
`Fig 10 is an embodiment of the design for improving the miniaturization of the near field communication (NFC) antenna and the coil for wireless
`charging to which the present invention is applied
`
`Fig 11 is an embodiment in which the component to which the present invention is applied is integrally mounted on top of the battery of a portable
`device
`
`Fig 12 is an example concerning a method for integrally mounting a component to which the present invention is applied on top of a metallic part of a
`portable device
`
`Examples of the metallic part are a shield can, and so forth
`
`Specific details for implementing the invention
`
`[0020] The prior art of the conventional coil for transmitting power for wireless charging and near field communication antennas is as follows
`
`[0021] In the prior art of a coil for transmitting power for a wireless charger, the conventional wireless charging method mounted a wireless charging
`circuit and a coil on a separate mounting instrument case from the outside and connected it to the external charging connect of a portable device to
`perform charging
`
`[0022] The size of the coil for wireless power transmission is designed to be large since it used 100 khz to 130 khz for the wireless power induction
`frequency
`
`[0023] Fig 1 is an embodiment of a coil for transmitting power for wireless charging the prior art, and the number of windings is also 8 turns, and the
`size has also been increased to 32 mm
`
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`Published Patent 10-2013-0000926
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`[0024] The size of the radius is also 32 mm
`
`[0025] Wireless charging power transmission induction frequency: 100 khz
`
`[0026] Pattern line width: 1.0 mm
`
`[0027] Gap between antenna lines: 0.3 mm
`
`[0028] Total number of windings (turns): 8 turns (4 turns x 1 layer x double-sided arrangement = 8 turns)
`
`[0029] Coil inductance: 4.2 μH
`
`[0030] As a prior art of a near field communication antenna, as for the conventional near field communication antenna, in a mobile
`phone, there is a method for mounting on a battery cover, and as another method, there is a method for mounting on top of a battery.
`
`[0031] 13.56 Mhz is used for the frequency for transmission and reception of the near field communication antenna and a loop antenna
`is used for the antenna method.
`
`[0032] Fig. 2 is an embodiment and characteristics of the design of a conventional near field communication antenna (NFC antenna).
`
`[0033] NFC frequency: 13.56 Mhz
`
`[0034] Line width: 0.9 mm
`
`[0035] Gap between lines: 0.2 mm
`
`[0036] Number of windings (turns): 4 turns
`
`[0037] Antenna inductance: 1.38 μH
`
`[0038] However, when a near field communication antenna is mounted on top of a battery, an electromagnetic wave absorber named
`ferrite sheet is used to prevent the electromagnetic field from being absorbed and lost into the battery metal concerning the magnetic
`field induced in the near field communication antenna due to the surface of the battery being metal, and it is attached between the near
`field communication antenna and the battery to minimize the loss of the induced magnetic field.
`
`[0039] An electromagnetic wave absorber sheet (also referred to as a ferrite sheet) is used to prevent loss of the electromagnetic field
`between the near field communication antenna and the battery into the battery metal and to prevent deterioration of the antenna
`performance, but the coil for wireless power transmission also suffers a significant loss in power transmission if there is no
`electromagnetic wave absorber sheet due to the loss of the electromagnetic field on top of the battery, so the electromagnetic wave
`absorber component of the ferrite sheet has components, such as nickel, copper, and zinc, and each manufacturer has different
`components and composition ratios.
`
`[0040] As for the characteristics of the generally used ferrite sheet, those with a permeability (μ) of about 130 or higher are used and
`those with a loss value at the level of 0.5 to 10 are used.
`
`[0041] In the present invention, the mounting area has been made small by designing the near field communication antenna and the
`coil for power transmission to share the same component space.
`
`[0042] To reduce the mounting area for the near field communication antenna and the coil for power transmission, an apparatus for
`mounting a coil for wireless power transmission inside the space comprising the near field communication antenna was formed, or an
`apparatus for mounting a near field communication antenna inside the space comprising the coil for power transmission was
`manufactured.
`
`[0043] Sharing the same component space in the design can reduce the mounting area, but
`
`[0044] by using the same space for the near field communication antenna and the coil for power transmission,
`
`[0045] there should be no degradation in the performance of the near field communication antenna due to mutual interference, and it
`should be designed such that there is no loss in power transmission.
`
`[0046] In other words, the coil for wireless power transmission was manufactured without degradation of the performance of the near
`field communication antenna, and also, it was made to have a mounting structure on top of a single board after manufacturing the near
`field communication antenna to ensure there is no loss in power transmission.
`
`[0047] To solve this problem, the present invention has established a cause analysis and countermeasures.
`
`[0048] The cause of the coil for transmitting power for wireless charging degrading the performance of the near field communication
`antenna is as follows.
`
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`Published Patent 10-2013-0000926
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`[0049] When a coil for power transmission is mounted inside the near field communication antenna, if it is placed on top of the near
`field communication input/output device, the near field communication input/output device emits a radio output at a frequency of
`13.56 Mhz. In this case, the radio output of 13.56 Mhz is induced to the near field communication antenna and as the induced current
`flows, an electromagnetic field gets generated around conducting wire of the antenna through which it flows, and in a similar manner,
`what is radio output at 13.56 Mhz from the near field communication input/output device is induced as an inductive coil to the coil
`for transmitting power for wireless charging as well, which causes the induced current to flow, and an electromagnetic field gets
`generated around the conducting wire for the coil for power transmission.
`
`[0050] The electromagnetic field generated in the conducting wire of the coil for power transmission works to cancel the
`electromagnetic field generated in the near field communication antenna.
`
`[0051] Therefore, the current induced in the near field communication antenna is attenuated, which deteriorates the reception
`performance.
`
`[0052] Similarly, when charging wirelessly, on the contrary, the electromagnetic field of the antenna generated by the induced
`current induced and flowing in the near field communication antenna by inductive frequency power for wireless charging
`works to cancel the electromagnetic field generated by the induced current flowing in the secondary power transmission coil,
`causing a loss in power transmission.
`
`[0053] In the present invention, it was experimentally found that this could be solved by providing a small gap for a space
`between the near field communication antenna and the power transmission coil to reduce the interference that cancels these
`mutual inductive electromagnetic fields. Theoretically, when the current (I) flowing in the conducting wire flows, the strength
`of magnetic flux and the strength of electromagnetic field (H) distributed around the conducting wire,
`
`[0054] the strength of magnetic flux B = 4 π x 10n x H
`
`[0055] = 4 π x 10n x 1/ (2 π) x I/r
`
`[0056] = 2 x 10n x I/r (A/m)
`
`[0057] r: Distance from the conducting wire (m)
`
`[0058] I; Current flowing in the conducting wire (A), (n = -7)
`
`[0059] Strength of electromagnetic field H = I / 2π r = 1/ (2π) x I/r (A/m).
`
`[0060] In Fig. 4,
`
`[0061] the current flowing in the conducting wire and the distribution pattern of the electromagnetic field distributed around
`the conducting wire are shown.
`
`[0062] With respect to the current flowing in said conducting wire, the strength of the electromagnetic field at a distance “r”
`distributed around the conducting wire gradually decreases in inverse proportion to the distance away from the conducting
`wire.
`
`[0063] It can be seen that the electromagnetic field is distributed to a certain distance, and thus the magnetic flux and the
`electromagnetic field are distributed in inverse proportion to the distance between the adjacent conducting wires, that is, the
`near field communication antenna and the power transmission coil.
`
`[0064] In Fig. 5,
`
`[0065] the magnitude of the influence of the intensity of the magnetic flux of the power transmission coil concerning the size
`of degradation of the reception in the near field communication antenna depending on the near field communication antenna
`and the coil for power transmission is illustrated and described in a graph.
`
`[0066] Fig. 7 is a diagram of a test for testing the present invention.
`
`[0067] A block diagram of a test on the correlation in the antenna performance degradation test according to the gap length
`between the near field communication antenna and the coil for power transmission is shown.
`
`[0068] The results of the test on the performance of the near field communication antenna according to the gap between the
`near field communication antenna and the power transmission coil are as follows.
`
`
`
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`Published Patent 10-2013-0000926
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`[0069]
`
`Gap
`distance of separation between near
`field communication antenna - power
`transmission coil
`1.5 mm
`3.0 mm
`4.0 mm
`5.0 mm
`
`
`
`Specification
`communication distance
`
`Performance of near field communication antenna
`(operating distance between near field communication
`antenna and near field communication device)
`
`40 mm
`40 mm
`40 mm
`40 mm
`
`6.0 mm
`50 mm
`54 mm
`55 mm
`
`[0070] Looking at the results of the test on the gap concerning the degradation in the reception sensitivity performance and the gap between
`the near field communication antenna and the coil for power transmission, when the gap is between 0 mm to 1.5 mm, the operating distance
`between the near field communication reader device and the near field communication antenna was only 6 mm due to the severe deterioration
`of the antenna performance, but
`
`[0071] It can be seen that, after the 3.0 mm gap arrangement, it changes rapidly to a level that is almost unaffected, satisfying the specification.
`
`[0072] In the case of a 5 mm gap arrangement, the operating distance between the near field communication reader and the antenna becomes
`55 mm, showing that there is no attenuation that is mutually cancelling.
`
`[0073] As for the current performance standards of the near field communication antenna, according to the international standard, the operating
`distance between the near field communication reader and the near field communication antenna is 40 mm or longer.
`
`[0074] In the actual experiment, the results of the experiment conducted for each gap on how much this generated electromagnetic field affects
`the decrease in reception sensitivity on adjacent near field communication antennas showed that mutual performance degradation does not
`occur even when arranged with a very small gap, and a miniaturized design became possible.
`
`[0075] It can be seen experimentally that the mutual effect decreases rapidly when the induced electromagnetic field affecting the performance
`degradation with mutual interference is smaller than a certain size.
`
`[0076] In other words, it can be seen experimentally that if the strength of the magnetic flux, which is inversely proportional to the distance,
`is less than a certain strength, the rapid performance degradation due to mutual interference, that is, the induced electromotive force causing
`performance decrease decreases rapidly.
`
`[0077] In other words, it can be seen experimentally that if the strength of the magnetic flux, which is inversely proportional to th e distance,
`is less than a certain strength, the rapid performance degradation due to mutual interference, that is, the induced electromotive force causing
`performance decrease decreases rapidly.
`
`[0078] In other words, it can be seen that the effect on performance degradation is insignificant if it is designed with a small gap around a 3.0
`mm gap.
`
`[0079] As for the result of the experiment conducted for each gap on how much the generated electromagnetic field affects the decrease in
`reception sensitivity on adjacent near field communication antennas, it was found that mutual performance degradation does not occur even
`when arranged with a very small gap, and a miniaturized design became possible.
`
`[0080] Matters to be noted when testing the degradation of the performance of the near field communication antenna are as follows.
`
`[0081] If the power transmission coil is not connected to the charging circuit and the test is carried out in an open state, no induced current
`flows, which means no electromagnetic field is generated, therefore no degradation in the performance of the near field communication antenna
`occurs.
`
`[0082] Therefore, when testing, the test should be carried out by connecting a resistor (R) and a capacitor (C), which are equivalent circuits
`of the charging circuit to which the rectifier circuit of the portable device has been applied, to the power transmission coil in series, and the
`test should be carried by being prepared under the actual operating conditions by making a closed loop.
`
`[0083] Similarly, a matter to be noted when measuring the performance degradation of wirelessly transmitted power, that is, reduction in the
`transmitted power, is that the near field communication antenna must be connected to the antenna matching circuit and the near field
`communication transmission/reception circuit to form a closed loop.
`
`[0084] Looking at the results of the test on the gap concerning the degradation in the reception sensitivity performance and the gap between
`the near field communication antenna and the coil for power transmission, when the gap is between 0 mm to 1.5 mm, the operating distance
`between the near field communication reader device and the near field communication antenna was only 6 mm due to the severe deterioration
`of the antenna performance, but
`
`[0085] it can be seen that, after the 3.0 mm gap arrangement, it changes rapidly to a level that is almost unaffected, satisfying the specification.
`
`[0086] In the case of a 5 mm gap arrangement, the operating distance between the near field communication reader and the antenna becomes
`55 mm, showing that there is no attenuation that is mutually cancelling.
`
`
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`Published Patent 10-2013-0000926
`
`[0087] As for the current performance standards of the near field communication antenna, according to the international standard, the operating
`distance between the near field communication reader and the near field communication antenna is 40 mm or longer.
`
`[0088] However, in the actual experiment, the results of the experiment conducted for each gap on how much this generated electromagnetic
`field affects the decrease in reception sensitivity on adjacent near field communication antennas showed that mutual performa nce degradation
`does not occur even when arranged with a very small gap, and a miniaturized design became possible.
`
`[0089] With this test, a structure capable of miniaturization through a shared design by overlapping the components area without mutual
`performance degradation and design specifications for arranging with minimum gaps were also derived.
`
`[0090] Fig. 8 is a diagram block diagram of a wireless charger for testing the present invention, a diagram of a test for wireless power
`transmission, and the test result. When the gap arrangement allowing the performance of the near field communication antenna to sufficiently
`satisfy the standard is set to 3.0 mm, the result of testing the power transmission confirmed that 3.5 W (5 V 700 mA) transmits without loss.
`
`[0091] When the arrangement was designed with a 3 mm gap, it could be seen experimentally that wireless power transmission is also
`transmitted with almost no attenuation.
`
`[0092] The results of the test for causing attenuation in wireless power transmission according to the gap between the near field communication
`antenna and the wireless power transmission coil are as follows.
`
`[0093]
`
`power
`Wireless
`transmission power (W)
`3.5 W
`4.0 W
`5.0 W
`10 W
`15 W
`20 W
`
`Output (V x A)
`
`5 V x 700 mA
`5 V x 800 mA
`5 V x 1 A
`10 V x 1 A
`15 V x 1 A
`20 V x 1 A
`
`
`
`Minimum gap for causing attenuation in power transmission: gap between
`near field communication antenna - power transmission coil
`3.0 mm or less
`3.0 mm or less
`3.0 mm
`3.7 mm
`5.5 mm
`9.0 mm
`
`[0094] Concerning the power subject to wireless power transmission, it can be seen that there is no attenuation in power transmission up to
`5.0 W if the gap with the near field communication antenna is set to 3.0 mm, and
`
`[0095] it was confirmed experimentally that, to ensure there is no attenuation in 20 W output, the gap between the near field communication
`antenna and the power transmission coil should be at least 9.0 mm.
`
`[0096] Where 3 5 W to 5.0 W charging currently used in smartphones is required, wireless charging power can be transmitted while
`implementing through miniaturization with a small gap of about 3.0 mm.
`
`[0097] Fig. 3 is an embodiment for making the area of the coil for power transmission small in the present invention.
`
`[0098] To reduce the space for mounting components,
`
`[0099] to implement an apparatus for mounting a coil for wireless power transmission inside the space comprising the near field
`communication antenna, as a means to reduce the size such that a coil for wireless power transmission can be mounted inside the space
`comprising the near field communication antenna, 7.0 Mhz frequency was used for the induction power frequency.
`
`[0100] As an embodiment of the miniaturized design of the secondary coil for power transmission for wireless charging, the present coil is an
`example of designing it to be small to ensure that it can be sufficiently built-in inside the near field communication antenna.
`
`[0101] As a method for miniaturizing the coil, it was possible to miniaturize the coil by using a high frequency in the existing 100 KHZ range
`for the wireless charging induction frequency.
`
`[0102] As an embodiment, a wireless charging induction frequency of 7 Mhz was used, and it was designed and experimentally conducted to
`achieve power transmission of 3.5 W, which is the power for charging mobile phones.
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`[0103] In Fig. 3,
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`[0104] It is a design specification for an embodiment of the miniaturized design of the secondary coil for power transmission for wireless
`charging, and the miniaturization of the outer size of the coil was also implemented.
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`Page 8 of 43
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`Published Patent 10-2013-0000926
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`[0105] The size of the coil was also made small at 35.0 mm x 18.0 mm (w x l) to ensure that it could be mounted inside the space
`comprising the near field communication antenna, and the size of the conventional coil using 100 Khz for the induction power
`frequency, which is a conventional method, was large with a diameter of 32 mm.
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`[0106] - Outer size of the coil (w x l): 35.0 mm x 18.0 mm
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`[0107] - Wireless charging power transmission induction frequency: 7.0 Mhz
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`[0108] - Pattern line width: 0.9 mm
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`[0109] - Gap between pattern lines: 0.1 mm
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`[0110] - Total number of w