WO2011150586A1 - 数据卡类移动终端及其屏蔽罩 - Google Patents

数据卡类移动终端及其屏蔽罩 Download PDF

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Publication number
WO2011150586A1
WO2011150586A1 PCT/CN2010/075360 CN2010075360W WO2011150586A1 WO 2011150586 A1 WO2011150586 A1 WO 2011150586A1 CN 2010075360 W CN2010075360 W CN 2010075360W WO 2011150586 A1 WO2011150586 A1 WO 2011150586A1
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Prior art keywords
mobile terminal
data card
shield
card type
type mobile
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PCT/CN2010/075360
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English (en)
French (fr)
Inventor
刘建富
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中兴通讯股份有限公司
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Publication of WO2011150586A1 publication Critical patent/WO2011150586A1/zh

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0007—Casings
    • H05K9/0045—Casings being rigid plastic containers having a coating of shielding material
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/3827—Portable transceivers
    • H04B1/3833—Hand-held transceivers
    • H04B1/3838—Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Definitions

  • the present invention relates to a mobile terminal technology, and in particular to a data card type mobile terminal and a shield thereof.
  • BACKGROUND With the development of wireless technologies, Internet access through wireless modems (Modem) is becoming more and more popular, and in particular, data card type mobile terminals have the advantages of being convenient to be able to access the Internet anytime and anywhere. However, data card type mobile terminals tend to be placed close to the human body, and their electromagnetic radiation may cause harm to the human body.
  • SAR Specific Absorption Rate
  • the Specific Absorption Rate (SAR) is commonly used internationally to assess the effects of electromagnetic radiation on the human body. At present, the data card SAR value is getting higher and higher, and it has become an important indicator to measure performance.
  • the SAR value is caused by the unbalanced feeding of the antenna. It has been found experimentally that the maximum point of the SAR value is generally not in the antenna area, due to the influence of the terminal equipment such as the notebook computer of the mobile terminal type mobile terminal installed, the S AR value Hot spots are often located on the cover behind the antenna. At present, there is no good method for the SAR value of the descending antenna.
  • the conventional method is the conduction power of the descending terminal, or the absorbing material and the copper coating are attached to the shielding cover. These methods will bring about a large degree of radiation power of the antenna. The reduction, which in turn affects the user's call quality and data download rate.
  • a primary object of the present invention is to provide a data card type mobile terminal and a shield thereof to solve at least the above problems.
  • a shield for a data card type mobile terminal is provided, and a slot line is formed on an outer surface of the shield.
  • a slot line is provided on an outer surface of a shield cover, including: a shield cover having a slot line formed on an outer surface thereof.
  • FIG. 1 is a plan view of a data card type mobile terminal according to an embodiment of the present invention
  • FIG. 2 is a schematic view showing a surface current flow path of a cross-shaped groove shield cover according to the present invention
  • FIG. 4 is a SAR hotspot distribution diagram according to an embodiment of the present invention
  • FIG. 5 is an exploded view of any shape slot line in the embodiment of the present invention.
  • a shield of a data card type mobile terminal is provided, and a slot line is formed on an outer surface of the shield. It is found that the monopole antenna of the data card type mobile terminal is an unbalanced feed structure. In addition to the current on the antenna, a part of the current flows to the conductive medium below or behind the antenna, which causes the S AR to be too high. main reason. Most of the conductive medium under or behind the antenna is a shield of the data card type mobile terminal.
  • the slot line may be any shape capable of breaking the unbalanced current on the shield, such as a cross, a Y-shape or a T-shape.
  • the following provides a basis for the utility model.
  • Shield for card type mobile terminals. 1 is a schematic plan view of a data card type mobile terminal according to an embodiment of the present invention. As shown in FIG.
  • the main antenna is located at the end of the data card, and the diversity antenna is located at one side of the card, except for the clearing area of the antenna.
  • the USB swivel head is located at the other end of the data card.
  • the main antenna transmits power and receives power
  • the diversity antenna only serves as the receiving antenna.
  • the surface of the shield is provided with a cross-shaped groove. In order to reduce the SAR value of the antenna, the S AR value distribution map of the surface is measured by the S AR measurement system, the hot spot position of the S AR value is determined, and the corresponding position on the shield is found.
  • FIG. 2 is a schematic view showing the current flow path of the surface of the cross-shaped groove shield according to the present invention. The principle of opening the cross-shaped groove line on the surface of the shielding groove to reduce the SAR value is specifically analyzed below with reference to FIG. 2 . As shown in Fig.
  • the current on both sides of the horizontal slot is composed of a plurality of small current elements, and the current elements /, and / 2 on both sides of a certain slot line are based on the basic theory of the short electric dipole field.
  • the two current elements are approximately inverted, and the fields produced by the two current elements are as follows:
  • the electromagnetic field generated by the current element I is
  • the electromagnetic field generated by W o current element / 2 is:
  • the SAR value distribution map can be obtained by the SAR test system test, and FIG. 3 is an embodiment according to the present invention. Schematic diagram of the SAR test system. The method for obtaining the SAR value distribution map by the SAR test system is as follows: The data card mobile terminal accesses the notebook through the USB port.
  • the computer is fixed to the bottom of the tissue tank of the SAR test system, and the surface to be tested is 5 mm from the bottom of the tank. Run the SAR test system to obtain the SAR value distribution map of the surface. As shown in Fig. 4, the position of the center point of Fig. 4 is the peak position of the SAR value. By comparing the SAR value map with the data card itself, the corresponding position is determined on the shield. In the implementation process, after determining the position of the peak value of the SAR value, the specific slotting mode can be determined at the position of the peak value of the SAR value on the shield cover.
  • the specific slotting method is centered on the position of the peak value of the SAR value, and the two widths are 0.2mm -0.5mm mutually perpendicular slot lines.
  • the length of each slot line is between ⁇ /50- ⁇ /20 ( ⁇ is the wavelength of the electromagnetic wave sent by the mobile terminal) to ensure that the shielding effect of the shield cover is not affected.
  • a layer of absorbing material may also be applied to the outer surface of the slotted shield to further reduce the SAR value.
  • the above-mentioned cross-shaped groove is a relatively easy-to-implement groove-forming method, as shown in FIG. Any line on the outer surface of the shield can be decomposed into a combination of a horizontal line and a vertical line. Therefore, the slot line on the shield provided by the embodiment of the present invention is not limited to the cross-shaped slot line, and includes any purpose for reducing SAR.
  • the slot line form, for example, in the form of a slot line such as a ⁇ -shaped or a ⁇ -shaped shape.
  • a data card type mobile terminal is further provided.
  • the data card type mobile terminal includes a shielding cover, and a slot line is formed on an outer surface of the shielding cover.
  • the center position of the slot line on the shield of the data card type mobile terminal is located at a peak position of the specific absorption rate S AR of the shield.
  • the slot line on the shield of the data card type mobile terminal has a cross shape, and includes two sub slot lines perpendicular to each other.
  • the sub-groove line has a groove width of between 0.2 mm and 0.5 mm.
  • the length of the sub-slot line is between ⁇ /50- ⁇ /20, where ⁇ is the wavelength of the electromagnetic wave transmitted by the mobile terminal.
  • the outer surface of the shield of the data card type mobile terminal is affixed with an absorbing material.
  • the utility model uses the slot line on the outer surface of the shield of the data card type mobile terminal to destroy the unbalanced current which generates the SAR value problem, thereby achieving the effect of reducing the SAR value of the antenna. .
  • the above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Description

数据卡类移动终端及其屏蔽罩 技术领域 本实用新型涉及移动终端技术， 具体而言， 涉及一种数据卡类移动终端 及其屏蔽罩。 背景技术 随着无线技术的发展， 通过无线调制解调器（Modem )上网越来越流行， 特别是数据卡类移动终端具有携带方便能够随时随地上网的优点。 但是数据 卡类移动终端往往会紧贴人体放置， 其电磁辐射可能会对人体造成伤害。 国 际上普遍釆用比吸收率 （ Specific Absorption Rate, SAR ) 来评估电磁辐射对 人体的影响。 目前， 对数据卡 SAR值的要求越来越高， 它已成为衡量性能的 一项重要指标。 研究表明， SAR值是由天线的不平衡馈电引起的， 经过实验 发现， SAR值的最大点一般不在天线区域， 由于受安装数据卡类移动终端的 终端设备例如笔记本电脑的影响， S AR值的热点往往位于天线后方的展蔽罩 上。 目前降氏天线 SAR值还没有较好的方法，常规的方法为降氏终端的传导 功率， 或是在屏蔽罩上贴吸波材料和贴铜皮， 这些方法都会带来天线辐射功 率较大程度的降低， 进而影响用户的通话质量以及数据下载速率。 发明内容 本实用新型的主要目的在于提供一种数据卡类移动终端及其屏蔽罩， 以 至少解决上述问题。 根据本实用新型的一个方面， 提供了一种数据卡类移动终端的屏蔽罩， 该屏蔽罩的外表面上开设槽线。 根据本实用新型的另一方面， 提供了一种屏蔽罩的外表面上开设槽线， 包括： 屏蔽罩， 该屏蔽罩的外表面上开设槽线。 通过本实用新型， 釆用在数据卡类移动终端的屏蔽罩的外表面上开设槽 线， 破坏产生 SAR值问题的不平衡电流， 进而达到降低天线 SAR值的效果。 附图说明 此处所说明的附图用来提供对本实用新型的进一步理解， 构成本申请的 一部分， 本实用新型的示意性实施例及其说明用于解释本实用新型， 并不构 成对本实用新型的不当限定。 在附图中： 图 1是根据本实用新型实施例的数据卡类移动终端的平面示意图； 图 2 是根据本实用新型的开设十字形槽屏蔽罩表面电流流动路径示意 图； 图 3是才艮据本实用新型实施例的 SAR测试系统示意图； 图 4是才艮据本实用新型实施例的 SAR热点分布图； 图 5是 居本实用新型实施例的任意形状槽线分解示意图。 具体实施方式 下文中将参考附图并结合实施例来详细说明本实用新型。需要说明的是， 在不冲突的情况下， 本申请中的实施例及实施例中的特征可以相互组合。 根据本实用新型的实施例， 提供了一种数据卡类移动终端的屏蔽罩， 该 屏蔽罩的外表面上开设槽线。 经分析发现， 数据卡类移动终端的单极子天线是不平衡馈电结构， 除了 天线上面的电流外， 还有一部分电流流向了天线下方或后方的导电介质， 这 是造成 S AR过高的主要原因。 天线下方或后方的导电介质大部分区域为数据卡类移动终端的屏蔽罩， 通过在屏蔽罩的外表面开设槽线， 可以破坏电流的流动路径， 使得屏蔽罩上 的电流蜿埏流动， 特别是截断电流路径的槽线两侧的电流方向刚好相反， 它 们在近场的磁场强度可以抵消，从而使得 SAR值的峰值会得到很大程度的降 低。 在实施过程中， 上述槽线可以为能够破环屏蔽罩上的不平衡电流的任意 形状， 例如十字形， Y字形或 T字形， 优选地， 以下以十字形槽线介绍本实 用新型提供的据卡类移动终端的屏蔽罩。 图 1是根据本实用新型实施例的数据卡类移动终端的平面示意图， 如图 1 所示， 主天线位于数据卡的末端， 分集天线位于卡的一侧， 除了天线的净 空区外， 其它部分为屏蔽罩的区域。 USB旋转头位于数据卡的另一端。 数据 卡正常工作时， 主天线发射功率和接收功率， 分集天线只作为接收天线。 如图 1所示， 屏蔽罩的表面开有十字形槽。 为了降低天线的 SAR值， 通 过 S AR测量系统测出该面的 S AR值分布图， 确定 S AR值的热点位置， 找到 屏蔽罩上的相应位置。 以该区域的中心位置为原点， 垂直于电流流动方向开 槽线， 然后从该槽线中点故垂直于上述槽线的槽线。 不平衡电流流经槽线时， 会被槽线截断， 这些电流流动方向各异， 所产生的近场相互叠加抵消， 会分 散 SAR值能量， 必然带来 SAR值的减小。 图 2 是根据本实用新型的开设十字形槽屏蔽罩表面电流流动路径示意 图，下面结合图 2具体分析在屏蔽槽的表面开设十字形槽线能够降低 SAR值 的原理。 如图 2所示， 水平槽两侧的电流由多个小电流元组成， 取某一段槽线两 侧的电流元 /,和/2 , 则根据短电偶极子场的基本理论， 在理想情况下， 这两 个电流元近似于反相， 两个电流元所产生的场如下： 电流元 I所产生的电磁场为
_ /1Jcos^ Kr/c)]
2πε0 c丄r +」 j cor
Figure imgf000005_0001
W o 电流元 /2所产生的电磁场为：
Figure imgf000006_0001
Hrl=H ('92 由电流元 I、和 /，所产生的电磁场叠加为
Figure imgf000006_0002
πε0 c r cr j cor
Figure imgf000006_0003
Hr=He = 0 由上述分析可以看出， 当 /,和/2反向时， /,和/2所产生的场强可以相互
¾消， 从而降低 SAR 值， 当两个电 ¾ϊ元等值反向， 即 / , = -12时，
Figure imgf000006_0004
He=Q。 此时由不平衡电流所产生的场最小， SAR值得到 降低。 为了确定开槽的具体位置， 需要确定屏蔽罩表面的 SAR值分布情况， 在 实施过程中， 可以但不限于通过 SAR测试系统测试得到 SAR值分布图， 图 3为才艮据本实用新型实施例的 SAR测试系统示意图。 通过 SAR测试系统测 试得到 SAR值分布图的方法如下： 数据卡移动终端通过 USB口接入笔记本 电脑，将电脑固定在 SAR测试系统组织液槽底，保持待测面距离槽底为 5mm。 运行 SAR测试系统， 得到该面的 SAR值分布图， 如图 4所示， 图 4中心点 的位置即为 SAR值的峰值位置。 通过对比 SAR值分布图和数据卡本身， 在 屏蔽罩上确定了相应位置。 在实施过程中 ,在确定 SAR值峰值的位置之后，可以 居屏蔽罩上 SAR 值峰值的位置确定具体的开槽方式，具体开槽方法为以 SAR值峰值的位置为 中心， 开两条宽度为 0.2mm -0.5mm的相互垂直的槽线。 其中， 每条槽线的 长度为 λ/50-λ/20之间（ λ为移动终端发送的电磁波的波长）， 以保证不影响展 蔽罩的屏蔽效果。 从而破坏了屏蔽槽上电流的流动路径， 使屏蔽槽上的电流 蜿埏流动， 特别是截断电流路径的槽线两侧的电流方向刚好相反， 它们在近 场的磁场强度刚好抵消， SAR值的峰值会得到很大程度的降低。 在实施过程中， 优选地， 也可在开槽的屏蔽罩的外表面上加一层吸波材 料， 从而进一步降低 SAR值。 需要说明的是， 上述十字形槽是一种比较容易实现的开槽方式， 如图 5 所示。 屏蔽罩外表面上的任何一条线都可以分解成水平线和垂直线的组合， 因此， 本实用新型实施例提供的屏蔽罩上的槽线并不仅限于十字形槽线， 还 包括任意以降 SAR为目的的槽线形式， 例如 Υ字形或 Τ字形等槽线形式。 根据本实用新型实施例， 还提供了一种数据卡类移动终端， 该数据卡类 移动终端包括屏蔽罩， 该屏蔽罩的外表面上开设槽线。 优选地， 该数据卡类移动终端的屏蔽罩上槽线的中心位置位于屏蔽罩的 比吸收率 S AR峰值位置。 优选地， 该数据卡类移动终端的屏蔽罩上槽线的形状为十字形， 包括相 互垂直的两条子槽线。 优选地， 上述子槽线的槽宽在 0.2mm至 0.5mm之间。 优选地， 上述子槽线的长度在 λ/50-λ/20之间， 其中， λ为移动终端发送 的电磁波的波长。 优选地， 该数据卡类移动终端的屏蔽罩的外表面上贴有吸波材料。 从以上的描述中， 可以看出， 本实用新型釆用在数据卡类移动终端的屏 蔽罩的外表面上开设槽线，破坏产生 SAR值问题的不平衡电流， 进而达到降 低天线 SAR值的效果。 以上所述仅为本实用新型的优选实施例而已，并不用于限制本实用新型， 对于本领域的技术人员来说， 本实用新型可以有各种更改和变化。 凡在本实 用新型的精神和原则之内， 所作的任何修改、 等同替换、 改进等， 均应包含 在本实用新型的保护范围之内。

Claims

权 利 要 求 书
1. 一种数据卡类移动终端的屏蔽罩， 其特征在于， 所述屏蔽罩的外表面上 开设槽线。
2. 根据权利要求 1所述的屏蔽罩， 其特征在于， 所述槽线的中心位置位于 未开设槽线的屏蔽罩的比吸收率 SAR峰值位置。
3. 根据权利要求 1所述的屏蔽罩， 其特征在于， 所述槽线的形状为十字形， 包括相互垂直的两条子槽线。
4. 根据权利要求 3所述的屏蔽罩，其特征在于，所述子槽线的槽宽在 0.2mm 至 0.5mm之间。
5. 根据权利要求 3 所述的屏蔽罩， 其特征在于， 所述子槽线的长度在 λ/50-λ/20之间， 其中， 所述 λ为所述移动终端发送的电磁波的波长。
6. 根据权利要求 1至 5任一项所述的屏蔽罩， 其特征在于， 所述屏蔽罩的 外表面上贴有吸波材料。
7. —种数据卡类移动终端， 其特征在于， 包括屏蔽罩， 所述屏蔽罩的外表 面上开设槽线。
8. 根据权利要求 7所述的数据卡类移动终端， 其特征在于， 所述槽线的中 心位置位于未开设槽线的屏蔽罩的比吸收率 SAR峰值位置。
9. 根据权利要求 7所述的数据卡类移动终端， 其特征在于， 所述槽线的形 状为十字形， 包括相互垂直的两条子槽线。
10. 根据权利要求 9所述的数据卡类移动终端， 其特征在于， 所述子槽线的 宽在 0.2mm至 0.5mm之间。
11. 根据权利要求 9所述的数据卡类移动终端， 其特征在于， 所述子槽线的 长度在 λ/50-λ/20 之间， 其中， 所述 λ为所述移动终端发送的电磁波的波 长。
12. 根据权利要求 7至 11任一项所述的数据卡类移动终端， 其特征在于， 所 述屏蔽罩的外表面上贴有吸波材料。
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002033592A (ja) * 2000-07-14 2002-01-31 Murata Mfg Co Ltd 電磁波遮断構造体
CN1334691A (zh) * 2000-07-14 2002-02-06 索尼株式会社 天线设备和便携式无线通信设备
US20050104793A1 (en) * 2003-11-18 2005-05-19 Alps Electric Co., Ltd. Circular polarization slot antenna apparatus capable of being easily miniaturized
CN1790810A (zh) * 2004-12-18 2006-06-21 乐金电子(中国)研究开发中心有限公司 设置有内置型平板天线的移动通信终端的电磁波屏蔽结构
CN201278544Y (zh) * 2008-09-12 2009-07-22 中兴通讯股份有限公司 无线通讯终端模块

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002033592A (ja) * 2000-07-14 2002-01-31 Murata Mfg Co Ltd 電磁波遮断構造体
CN1334691A (zh) * 2000-07-14 2002-02-06 索尼株式会社 天线设备和便携式无线通信设备
US20050104793A1 (en) * 2003-11-18 2005-05-19 Alps Electric Co., Ltd. Circular polarization slot antenna apparatus capable of being easily miniaturized
CN1790810A (zh) * 2004-12-18 2006-06-21 乐金电子(中国)研究开发中心有限公司 设置有内置型平板天线的移动通信终端的电磁波屏蔽结构
CN201278544Y (zh) * 2008-09-12 2009-07-22 中兴通讯股份有限公司 无线通讯终端模块

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