WO2010116463A1 - Communication module - Google Patents
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- WO2010116463A1 WO2010116463A1 PCT/JP2009/056547 JP2009056547W WO2010116463A1 WO 2010116463 A1 WO2010116463 A1 WO 2010116463A1 JP 2009056547 W JP2009056547 W JP 2009056547W WO 2010116463 A1 WO2010116463 A1 WO 2010116463A1
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- WIPO (PCT)
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- electromagnetic wave
- unnecessary
- wave absorber
- absorbing surface
- hollow structure
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B15/00—Suppression or limitation of noise or interference
- H04B15/02—Reducing interference from electric apparatus by means located at or near the interfering apparatus
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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
- H05K9/002—Casings with localised screening
- H05K9/0022—Casings with localised screening of components mounted on printed circuit boards [PCB]
- H05K9/0024—Shield cases mounted on a PCB, e.g. cans or caps or conformal shields
- H05K9/0029—Shield cases mounted on a PCB, e.g. cans or caps or conformal shields made from non-conductive materials intermixed with electro-conductive particles
Definitions
- the present invention relates to a communication module having an EMI (Electro Magnetic Interference) suppression mechanism.
- EMI Electro Magnetic Interference
- EMI electromagnetic interference
- EMI is a phenomenon in which electromagnetic waves emitted from electronic devices affect the operation of peripheral electronic devices.
- FIG. 7 is a diagram in which radiation of unwanted electromagnetic waves is suppressed by a metal shield case.
- a transmission line 51 that is a high-frequency pattern is laid on the printed circuit board 5, and noise due to unnecessary electromagnetic waves is generated at a noise generation point p on the transmission line 51 during transmission of a high-frequency signal on the transmission line 51 (for example, If the noise generation point p is a soldering point (via hole), an impedance shift occurs at the soldering point and unnecessary electromagnetic waves are generated).
- EMI to the electronic components around the noise generation point p can be prevented by covering the noise generation point p with the metal shield case 6.
- the metal member does not absorb the electromagnetic wave even if it is reflected, the unnecessary electromagnetic wave is not attenuated even if the metal shield case 6 is covered.
- FIG. 8 is a diagram showing the state of leakage of unnecessary electromagnetic waves by single-phase transmission and differential transmission.
- high-frequency transmission is performed by single-phase transmission using one transmission line 51
- unnecessary electromagnetic waves leak to the outside from the pattern of the transmission line 51.
- high-frequency transmission is performed by differential transmission in which a pair of transmission lines 51a and 51b transmit signals of opposite phases
- electromagnetic radiation is canceled out and unnecessary electromagnetic leakage is reduced.
- differential transmission if there are variations in the signal amplitudes of both transmission lines 51a and 51b, the effect of canceling unnecessary electromagnetic waves is reduced.
- FIG. 9 is a diagram showing how the effect of canceling unnecessary electromagnetic waves is reduced by differential transmission. As shown in the figure, if there is a significant difference between the signal amplitude level of the transmission line 51a and the signal amplitude level of the transmission line 51b, the effect of canceling the unnecessary electromagnetic wave is reduced, and the unnecessary electromagnetic wave is transmitted from the transmission line 51b having a large amplitude level. Leaks to the outside. Therefore, from the viewpoint of unnecessary electromagnetic radiation, this is the same as performing single-phase transmission.
- electromagnetic wave absorber or radio wave absorber
- EMI countermeasures have been implemented.
- rubber-like and clay-like electromagnetic wave absorbers have also been developed.
- JP 2006-140585 A paragraph number [0012]
- FIG. 10 is a diagram in which radiation of unwanted electromagnetic waves is suppressed by an electromagnetic wave absorber.
- the mode that the electromagnetic wave absorber 7 was directly affixed to the noise generation location p on the transmission lines 51a and 51b is shown. Unnecessary electromagnetic waves can be suppressed by installing the electromagnetic wave absorber 7 at the noise generation point p.
- the electromagnetic wave absorber 7 is directly attached to the signal pattern, even the high frequency component of the main signal flowing through the transmission lines 51a and 51b is absorbed by the electromagnetic wave absorber 7, and the waveform of the main signal is deteriorated. (For example, jitter occurs in the main signal or deterioration occurs in the rising / falling edges of the main signal).
- the electromagnetic wave absorber 7 is installed on the printed circuit board 5 so as to cover the noise generating portion p without directly attaching the electromagnetic wave absorber 7 to the signal pattern, the electromagnetic wave absorber 7 and the signal pattern are If it is located in the vicinity, the main signal will be affected.
- the present invention has been made in view of such points, and an object thereof is to provide a communication module that efficiently suppresses EMI using an electromagnetic wave absorber without affecting a main signal.
- Another object of the present invention is to provide an electromagnetic wave absorber that efficiently suppresses EMI without affecting the main signal.
- the communication module includes a printed circuit board and an electromagnetic wave absorber that covers the unnecessary electromagnetic wave generation portion where the unnecessary electromagnetic wave is generated on the printed circuit board and absorbs the unnecessary electromagnetic wave.
- the electromagnetic wave absorber has a hollow structure provided with an electromagnetic wave absorbing surface on which unnecessary electromagnetic waves are vertically incident.
- FIG. 1 is a diagram showing a communication module in which an electromagnetic wave absorber is installed on a printed board.
- the communication module 1 includes a printed circuit board 10 and an electromagnetic wave absorber 20.
- the electromagnetic wave absorber 20 is installed on the printed circuit board 10 so as to cover the unnecessary electromagnetic wave generation site 11a where the unnecessary electromagnetic wave is generated on the printed circuit board 10, and absorbs the unnecessary electromagnetic wave. Further, the electromagnetic wave absorber 20 has a hollow structure provided with an electromagnetic wave absorbing surface on which unnecessary electromagnetic waves are perpendicularly incident on the medium of the electromagnetic wave absorber 20.
- the electromagnetic wave absorber has the largest loss of vertically incident electromagnetic waves. That is, when unnecessary electromagnetic waves are incident on the electromagnetic wave absorber, the absorption efficiency is highest and the EMI suppression effect is high when the electromagnetic waves are vertically incident.
- the medium of the electromagnetic wave absorber exists at a position away from the transmission line 11 by a certain distance. Is required.
- the hollow structure of the electromagnetic wave absorber 20 has a structure having electromagnetic wave absorbing surfaces 21 to 23 as shown in FIG.
- the electromagnetic wave absorbing surface 21 is a surface on which unnecessary electromagnetic waves radiated in the horizontal direction from the unnecessary electromagnetic wave generation location 11a are vertically incident.
- the electromagnetic wave absorbing surface 22 is a surface on which unwanted electromagnetic waves radiated at an angle of 45 degrees obliquely with respect to the horizontal direction from the unwanted electromagnetic wave generation location 11a are vertically incident.
- the electromagnetic wave absorbing surface 23 is a surface on which unnecessary electromagnetic waves radiated in the vertical direction from the unnecessary electromagnetic wave generation location 11a are vertically incident.
- the electromagnetic wave absorber 20 Since the electromagnetic wave absorber 20 has such a hollow structure, the electromagnetic wave absorbing surface 21 absorbs the unnecessary electromagnetic wave radiated in the horizontal direction to the maximum, and the electromagnetic wave absorbing surface 22 is inclined 45 with respect to the horizontal direction. Unwanted electromagnetic waves radiated at an angle of degrees can be absorbed to the maximum, and the electromagnetic wave absorbing surface 23 can absorb the unnecessary electromagnetic waves radiated in the vertical direction to the maximum.
- the medium of the electromagnetic wave absorber 20 can be separated from the transmission line 11 by such a hollow structure. Therefore, the transmission signal flowing through the transmission line 11 is not affected.
- the thickness of the medium of the electromagnetic wave absorber 20 is set to a required thickness.
- the electromagnetic wave absorber 20 is processed so that the thickness d is at least 3 mm (a method for calculating the thickness will be described later).
- FIG. 2 is a diagram showing the difference in the effect of absorbing unnecessary electromagnetic waves of electromagnetic wave absorbers having different hollow structures.
- the electromagnetic wave absorber 200 having a square (U-shaped) hollow structure the electromagnetic wave radiated at an angle of 45 degrees from the unnecessary electromagnetic wave generation site 11a does not vertically enter the medium of the electromagnetic wave absorber 200, and thus the absorption rate decreases. It will be. For this reason, the reflectance of the unnecessary electromagnetic wave inside the hollow structure is increased, and the unnecessary electromagnetic wave is likely to leak from the gap between the installation surfaces of the electromagnetic wave absorber 200 and the printed board 10.
- the electromagnetic wave absorber 20 shown in FIG. 1 even an unnecessary electromagnetic wave radiated at an angle of 45 degrees from the unnecessary electromagnetic wave generation location 11 a is perpendicularly incident on the medium of the electromagnetic wave absorber 20. Compared with the electromagnetic wave absorber 200, the reflectance of unnecessary electromagnetic waves inside the hollow structure can be reduced. For this reason, it is possible to prevent unnecessary electromagnetic waves from leaking from the gap between the installation surfaces of the electromagnetic wave absorber 20 and the printed circuit board 10.
- FIG. 3 is a diagram showing a communication module in which an electromagnetic wave absorber is installed on a printed board.
- the communication module 1a includes a printed circuit board 10 and an electromagnetic wave absorber 20a.
- the electromagnetic wave absorber 20a is installed on the printed circuit board 10 so as to cover the unnecessary electromagnetic wave generation site 11a where the unnecessary electromagnetic wave is generated on the printed circuit board 10, and absorbs the unnecessary electromagnetic wave.
- the electromagnetic wave absorber 20a has a hollow structure in which unnecessary electromagnetic waves are perpendicularly incident on the medium of the electromagnetic wave absorber 20a. Specifically, the hollow structure has a hemispherical structure.
- the electromagnetic wave absorbing surface in this space is all radiated from the unnecessary electromagnetic wave generation location 11a. Since the incident angle of the unnecessary electromagnetic wave becomes vertical, the absorption efficiency can be maximized.
- the medium of the electromagnetic wave absorber 20a can be separated from the transmission line 11 by a certain distance by such a hollow structure. Therefore, the transmission signal flowing through the transmission line 11 is not affected.
- FIG. 4 shows an overview of the electromagnetic wave absorber 20a. 3 and 4, the outer shape of the electromagnetic wave absorber 20a is rectangular, but the outer shape may be a semispherical shape like the electromagnetic wave absorber 20a-1 shown in FIG.
- FIG. 6 is a diagram showing a communication module in which an electromagnetic wave absorber is installed on a printed board.
- the communication module 1b includes a printed circuit board 10 and an electromagnetic wave absorber 20b.
- the electromagnetic wave absorber 20b is installed on the printed circuit board 10 so as to cover the unnecessary electromagnetic wave generation portions 11a and 11b where unnecessary electromagnetic waves are generated on the printed circuit board 10, and absorbs the unnecessary electromagnetic waves.
- the electromagnetic wave absorber 20b has a hollow structure in which unnecessary electromagnetic waves are perpendicularly incident on the medium of the electromagnetic wave absorber 20b.
- the hollow structure has a semi-cylindrical structure.
- the electromagnetic wave absorber having a hollow structure with a semi-cylindrical structure so as to cover the plurality of unnecessary electromagnetic wave generation points 20b is effective.
- the incident angle of all the unnecessary electromagnetic waves radiated from the unnecessary electromagnetic wave generation points 11a and 11b is obtained by covering the unnecessary electromagnetic wave generation points 11a and 11b with the space of the electromagnetic wave absorber 20b having a hollow cylindrical structure. Since it becomes vertical, the absorption efficiency can be maximized.
- the unnecessary electromagnetic wave generation points 11a and 11b are on the transmission line 11 laid on the printed circuit board 10.
- the hollow structure allows the medium of the electromagnetic wave absorber 20b to be separated from the transmission line 11 by a certain distance. Therefore, the transmission signal flowing through the transmission line 11 is not affected.
- the electromagnetic wave absorber 20 b having a hollow semi-cylindrical structure is installed to suppress EMI, but in the differential transmission by two transmission lines. Similarly, EMI can be suppressed by installing the electromagnetic wave absorber 20b at the location where the unnecessary electromagnetic wave is generated.
- the complex relative dielectric constant ⁇ r of the electromagnetic wave absorber 20 can be expressed by Expression (1).
- ⁇ a is the dielectric constant of the real part
- ⁇ b is the dielectric constant of the complex part.
- ⁇ is the wavelength
- d is the thickness of the electromagnetic wave absorber.
- the incident angle to the electromagnetic wave absorber is ⁇ with respect to the vertical axis, the following equation (2a) is used.
- the hollow structure of the electromagnetic wave absorber has a structure including an electromagnetic wave absorbing surface on which unnecessary electromagnetic waves are vertically incident. As a result, it is possible to efficiently suppress EMI without affecting the main signal.
Abstract
The radiation of unwanted electromagnetic waves can be suppressed. An electromagnetic wave absorber (20) has a hollow structure for allowing an unwanted electromagnetic wave to be incident perpendicular to the medium of the electromagnetic wave absorber (20). The hollow structure of the electromagnetic wave absorber (20) comprises: a first electromagnetic wave absorbing surface (21), perpendicular to which an unwanted electromagnetic wave radiated in the horizontal direction from an unwanted electromagnetic wave generation source (11a) is incident; a second electromagnetic wave absorbing surface (22), perpendicular to which an unwanted electromagnetic wave radiated at a tilt angle of 45 degrees to the horizontal direction from the unwanted electromagnetic wave generation source (11a) is incident; and a third electromagnetic wave absorbing surface (23), perpendicular to which an unwanted electromagnetic wave radiated in the vertical direction from the unwanted electromagnetic wave generation source (11a) is incident.
Description
本発明は、ＥＭＩ（Electro Magnetic Interference）の抑制機構を有する通信モジュールに関する。
The present invention relates to a communication module having an EMI (Electro Magnetic Interference) suppression mechanism.
近年、電子機器の高機能化・小型軽量化が進むにつれて、回路の高速化、部品実装の高密度化が一層進んできており、これに伴うＥＭＩへの対策がますます重要視されてきている。ＥＭＩとは、電磁妨害のことであり、電子機器が発する電磁波が周辺電子機器の動作に影響を及ぼす現象のことである。
In recent years, as electronic devices have become more sophisticated, smaller, and lighter, the speed of circuits and the density of component mounting have further increased, and countermeasures against EMI associated therewith have become increasingly important. . EMI is electromagnetic interference, and is a phenomenon in which electromagnetic waves emitted from electronic devices affect the operation of peripheral electronic devices.
ＥＭＩの従来の対策としては、不要電磁波が輻射される箇所に、金属シールドのケースを被せたり、または高周波信号の高速伝送時には、単相伝送とはせずに、差動伝送で情報伝達を行ったりしていた。
As a conventional measure against EMI, the case where unnecessary electromagnetic waves are radiated is covered with a metal shield case, or when high-frequency signals are transmitted at high speed, information transmission is performed by differential transmission instead of single-phase transmission. I was doing.
図７は金属シールドケースによって不要電磁波の輻射抑制を行う図である。プリント基板５上に高周波パターンである伝送ライン５１が敷設され、伝送ライン５１での高周波信号の伝送時に、伝送ライン５１上の雑音発生箇所ｐにおいて不要電磁波による雑音が発生するものとする（例えば、雑音発生箇所ｐが半田付け箇所（ビアホール）であったりすると、その半田付け箇所でインピーダンスずれが生じて不要電磁波が発生する）。
FIG. 7 is a diagram in which radiation of unwanted electromagnetic waves is suppressed by a metal shield case. A transmission line 51 that is a high-frequency pattern is laid on the printed circuit board 5, and noise due to unnecessary electromagnetic waves is generated at a noise generation point p on the transmission line 51 during transmission of a high-frequency signal on the transmission line 51 (for example, If the noise generation point p is a soldering point (via hole), an impedance shift occurs at the soldering point and unnecessary electromagnetic waves are generated).
このような場合、雑音発生箇所ｐを金属シールドケース６で覆うことによって、雑音発生箇所ｐ周辺の電子部品へのＥＭＩを防ぐことができる。しかし、金属部材は、電磁波を反射はしても吸収はしないため、金属シールドケース６を被せても不要電磁波が減衰することはない。
In such a case, EMI to the electronic components around the noise generation point p can be prevented by covering the noise generation point p with the metal shield case 6. However, since the metal member does not absorb the electromagnetic wave even if it is reflected, the unnecessary electromagnetic wave is not attenuated even if the metal shield case 6 is covered.
したがって、金属シールドケース６で雑音発生箇所ｐを覆っても、金属シールドケース６とプリント基板５との設置面に隙間があると、その隙間から金属シールドケース６の内部で反射した不要電磁波が外部へ漏洩してしまう恐れがあり、ＥＭＩの効果が得られないことがあった。または、金属シールドケース６内の不要電磁波が、プリント基板５上の電源パターンを通じて漏洩する場合もあった。
Therefore, even if the noise generation point p is covered with the metal shield case 6, if there is a gap on the installation surface between the metal shield case 6 and the printed circuit board 5, unnecessary electromagnetic waves reflected inside the metal shield case 6 from the gap are externally applied. The EMI effect may not be obtained. Or the unnecessary electromagnetic wave in the metal shield case 6 may leak through the power supply pattern on the printed circuit board 5.
図８は単相伝送と差動伝送による不要電磁波の漏洩の様子を示す図である。１本の伝送ライン５１による単相伝送で高周波伝送を行うと、伝送ライン５１のパターンから不要電磁波が外部に漏洩する。これに対し、対をなす２本の伝送ライン５１ａ、５１ｂでそれぞれ逆位相の信号を伝送する差動伝送によって高周波伝送を行うと、電磁波輻射が互いに打ち消され、不要電磁波の外部漏洩が小さくなる。しかし、差動伝送においても、両者の伝送ライン５１ａ、５１ｂの信号振幅にばらつきがあると、不要電磁波の打ち消し効果が低減してしまう。
FIG. 8 is a diagram showing the state of leakage of unnecessary electromagnetic waves by single-phase transmission and differential transmission. When high-frequency transmission is performed by single-phase transmission using one transmission line 51, unnecessary electromagnetic waves leak to the outside from the pattern of the transmission line 51. On the other hand, when high-frequency transmission is performed by differential transmission in which a pair of transmission lines 51a and 51b transmit signals of opposite phases, electromagnetic radiation is canceled out and unnecessary electromagnetic leakage is reduced. However, even in differential transmission, if there are variations in the signal amplitudes of both transmission lines 51a and 51b, the effect of canceling unnecessary electromagnetic waves is reduced.
図９は差動伝送で不要電磁波の打ち消し効果が低減する様子を示す図である。図に示すように、伝送ライン５１ａの信号振幅レベルと、伝送ライン５１ｂの信号振幅レベルとに顕著な差があると、不要電磁波の打ち消し効果が低減し、振幅レベルの大きな伝送ライン５１ｂから不要電磁波が外部へ漏洩してしまう。したがって、不要電磁波輻射の観点から見れば、単相伝送を行っているのと同じことになってしまう。
FIG. 9 is a diagram showing how the effect of canceling unnecessary electromagnetic waves is reduced by differential transmission. As shown in the figure, if there is a significant difference between the signal amplitude level of the transmission line 51a and the signal amplitude level of the transmission line 51b, the effect of canceling the unnecessary electromagnetic wave is reduced, and the unnecessary electromagnetic wave is transmitted from the transmission line 51b having a large amplitude level. Leaks to the outside. Therefore, from the viewpoint of unnecessary electromagnetic radiation, this is the same as performing single-phase transmission.
一方、近年になって、電磁波吸収体（または電波吸収体）と呼ばれる、電磁波エネルギーを熱エネルギーに変換して、最終的には空中へ放射する媒体が開発されており、電磁波吸収体を用いたＥＭＩ対策が実施されるようになってきた。現在は、ゴム状や粘土状の電磁波吸収体も開発されている。
On the other hand, in recent years, a medium called electromagnetic wave absorber (or radio wave absorber) that converts electromagnetic wave energy into heat energy and finally radiates it into the air has been developed. EMI countermeasures have been implemented. Currently, rubber-like and clay-like electromagnetic wave absorbers have also been developed.
従来のＥＭＩ対策技術として、電波吸収体の絶縁体上に、フレキシブル配線基板を設けて不要電磁波輻射の抑制を図る技術が提案されている。
特開２００６－１４０５８５号公報（段落番号〔００１２〕）
As a conventional EMI countermeasure technique, a technique has been proposed in which a flexible wiring board is provided on an insulator of a radio wave absorber to suppress unnecessary electromagnetic radiation.
JP 2006-140585 A (paragraph number [0012])
電磁波吸収体を用いることで、不要電磁波輻射を抑制することが可能であるが、電磁波吸収体の設置方法が適切でないと、主信号にも悪影響を与えてしまう恐れがあった。
図１０は電磁波吸収体によって不要電磁波の輻射抑制を行っている図である。伝送ライン５１ａ、５１ｂ上の雑音発生箇所ｐに電磁波吸収体７を直接貼り付けた様子を示している。電磁波吸収体７を雑音発生箇所ｐに設置することで、不要電磁波を抑制することができる。 Although it is possible to suppress unnecessary electromagnetic radiation by using the electromagnetic wave absorber, the main signal may be adversely affected if the installation method of the electromagnetic wave absorber is not appropriate.
FIG. 10 is a diagram in which radiation of unwanted electromagnetic waves is suppressed by an electromagnetic wave absorber. The mode that the electromagnetic wave absorber 7 was directly affixed to the noise generation location p on the transmission lines 51a and 51b is shown. Unnecessary electromagnetic waves can be suppressed by installing the electromagnetic wave absorber 7 at the noise generation point p.
図１０は電磁波吸収体によって不要電磁波の輻射抑制を行っている図である。伝送ライン５１ａ、５１ｂ上の雑音発生箇所ｐに電磁波吸収体７を直接貼り付けた様子を示している。電磁波吸収体７を雑音発生箇所ｐに設置することで、不要電磁波を抑制することができる。 Although it is possible to suppress unnecessary electromagnetic radiation by using the electromagnetic wave absorber, the main signal may be adversely affected if the installation method of the electromagnetic wave absorber is not appropriate.
FIG. 10 is a diagram in which radiation of unwanted electromagnetic waves is suppressed by an electromagnetic wave absorber. The mode that the electromagnetic wave absorber 7 was directly affixed to the noise generation location p on the
しかし、電磁波吸収体７を信号パターンに直接貼り付けると、伝送ライン５１ａ、５１ｂを流れる主信号の高周波成分までが電磁波吸収体７に吸収されてしまい、主信号の波形に劣化が生じることになる（例えば、主信号にジッタが生じたり、主信号の立ち上がり／立ち下りエッジに劣化が生じたりする）。
However, if the electromagnetic wave absorber 7 is directly attached to the signal pattern, even the high frequency component of the main signal flowing through the transmission lines 51a and 51b is absorbed by the electromagnetic wave absorber 7, and the waveform of the main signal is deteriorated. (For example, jitter occurs in the main signal or deterioration occurs in the rising / falling edges of the main signal).
また、電磁波吸収体７を信号パターンに直接貼り付けずに、雑音発生箇所ｐを覆うように電磁波吸収体７をプリント基板５に設置した場合であっても、電磁波吸収体７と信号パターンとが近接に位置してしまうと、主信号に影響を与えることになる。
Further, even when the electromagnetic wave absorber 7 is installed on the printed circuit board 5 so as to cover the noise generating portion p without directly attaching the electromagnetic wave absorber 7 to the signal pattern, the electromagnetic wave absorber 7 and the signal pattern are If it is located in the vicinity, the main signal will be affected.
したがって、主信号に影響は与えずに、かつ不要電磁波の漏洩輻射は効果的に抑制することが可能な構造を持つ電磁波吸収体を用いて、ＥＭＩ対策を行う必要がある。
本発明はこのような点に鑑みてなされたものであり、主信号に影響を与えずに、電磁波吸収体を用いて効率よくＥＭＩの抑制を行う通信モジュールを提供することを目的とする。 Therefore, it is necessary to take EMI countermeasures by using an electromagnetic wave absorber having a structure that can effectively suppress leakage radiation of unnecessary electromagnetic waves without affecting the main signal.
The present invention has been made in view of such points, and an object thereof is to provide a communication module that efficiently suppresses EMI using an electromagnetic wave absorber without affecting a main signal.
本発明はこのような点に鑑みてなされたものであり、主信号に影響を与えずに、電磁波吸収体を用いて効率よくＥＭＩの抑制を行う通信モジュールを提供することを目的とする。 Therefore, it is necessary to take EMI countermeasures by using an electromagnetic wave absorber having a structure that can effectively suppress leakage radiation of unnecessary electromagnetic waves without affecting the main signal.
The present invention has been made in view of such points, and an object thereof is to provide a communication module that efficiently suppresses EMI using an electromagnetic wave absorber without affecting a main signal.
また、本発明の他の目的は、主信号に影響を与えずに、効率よくＥＭＩの抑制を行う電磁波吸収体を提供することである。
Another object of the present invention is to provide an electromagnetic wave absorber that efficiently suppresses EMI without affecting the main signal.
上記課題を解決するために、通信モジュールが提供される。この通信モジュールは、プリント基板と、前記プリント基板上で不要電磁波が発生する不要電磁波発生箇所を覆って、前記不要電磁波を吸収する電磁波吸収体とを備える。ここで、電磁波吸収体は、不要電磁波が垂直入射する電磁波吸収面を備えた中空構造を有する。
In order to solve the above problems, a communication module is provided. The communication module includes a printed circuit board and an electromagnetic wave absorber that covers the unnecessary electromagnetic wave generation portion where the unnecessary electromagnetic wave is generated on the printed circuit board and absorbs the unnecessary electromagnetic wave. Here, the electromagnetic wave absorber has a hollow structure provided with an electromagnetic wave absorbing surface on which unnecessary electromagnetic waves are vertically incident.
不要電磁波の輻射の抑制を図ることが可能になる。
本発明の上記および他の目的、特徴および利点は本発明の例として好ましい実施の形態を表す添付の図面と関連した以下の説明により明らかになるであろう。 It is possible to suppress the radiation of unnecessary electromagnetic waves.
These and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments by way of example of the present invention.
本発明の上記および他の目的、特徴および利点は本発明の例として好ましい実施の形態を表す添付の図面と関連した以下の説明により明らかになるであろう。 It is possible to suppress the radiation of unnecessary electromagnetic waves.
These and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments by way of example of the present invention.
以下、本発明の実施の形態を図面を参照して説明する。図１はプリント基板上に電磁波吸収体が設置されている通信モジュールを示す図である。通信モジュール１は、プリント基板１０と電磁波吸収体２０を備える。
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a communication module in which an electromagnetic wave absorber is installed on a printed board. The communication module 1 includes a printed circuit board 10 and an electromagnetic wave absorber 20.
電磁波吸収体２０は、プリント基板１０上で不要電磁波が発生する不要電磁波発生箇所１１ａを覆うようにプリント基板１０に設置して、不要電磁波の吸収を行う。また、電磁波吸収体２０は、不要電磁波が電磁波吸収体２０の媒質に垂直入射する電磁波吸収面を備えた中空構造を有している。
The electromagnetic wave absorber 20 is installed on the printed circuit board 10 so as to cover the unnecessary electromagnetic wave generation site 11a where the unnecessary electromagnetic wave is generated on the printed circuit board 10, and absorbs the unnecessary electromagnetic wave. Further, the electromagnetic wave absorber 20 has a hollow structure provided with an electromagnetic wave absorbing surface on which unnecessary electromagnetic waves are perpendicularly incident on the medium of the electromagnetic wave absorber 20.
ここで、一般に、電磁波吸収体は、垂直入射した不要電磁波の損失が最大となる。すなわち、不要電磁波が電磁波吸収体に入射する場合、垂直入射した場合が最も吸収効率が高くＥＭＩ抑制効果が高い。
Here, generally, the electromagnetic wave absorber has the largest loss of vertically incident electromagnetic waves. That is, when unnecessary electromagnetic waves are incident on the electromagnetic wave absorber, the absorption efficiency is highest and the EMI suppression effect is high when the electromagnetic waves are vertically incident.
また、プリント基板１０に敷設されている伝送ライン１１を流れる主信号に影響を与えないようにするためには、伝送ライン１１から一定の距離を離した位置に電磁波吸収体の媒質が存在することが必要となる。
Further, in order not to affect the main signal flowing through the transmission line 11 laid on the printed circuit board 10, the medium of the electromagnetic wave absorber exists at a position away from the transmission line 11 by a certain distance. Is required.
そこで、電磁波吸収体２０の中空構造としては、図１に示すように、電磁波吸収面２１～２３を持つような構造とする。電磁波吸収面２１は、不要電磁波発生箇所１１ａから水平方向に輻射した不要電磁波が垂直入射する面である。
Therefore, the hollow structure of the electromagnetic wave absorber 20 has a structure having electromagnetic wave absorbing surfaces 21 to 23 as shown in FIG. The electromagnetic wave absorbing surface 21 is a surface on which unnecessary electromagnetic waves radiated in the horizontal direction from the unnecessary electromagnetic wave generation location 11a are vertically incident.
電磁波吸収面２２は、不要電磁波発生箇所１１ａから水平方向に対して斜め４５度の角度で輻射した不要電磁波が垂直入射する面である。電磁波吸収面２３は、不要電磁波発生箇所１１ａから垂直方向に輻射した不要電磁波が垂直入射する面である。
The electromagnetic wave absorbing surface 22 is a surface on which unwanted electromagnetic waves radiated at an angle of 45 degrees obliquely with respect to the horizontal direction from the unwanted electromagnetic wave generation location 11a are vertically incident. The electromagnetic wave absorbing surface 23 is a surface on which unnecessary electromagnetic waves radiated in the vertical direction from the unnecessary electromagnetic wave generation location 11a are vertically incident.
電磁波吸収体２０が、このような中空構造を持つことにより、電磁波吸収面２１によって、水平方向に輻射した不要電磁波を最大限に吸収し、また電磁波吸収面２２によって、水平方向に対して斜め４５度の角度で輻射した不要電磁波を最大限に吸収し、さらに電磁波吸収面２３によって、垂直方向に輻射した不要電磁波を最大限に吸収することができる。
Since the electromagnetic wave absorber 20 has such a hollow structure, the electromagnetic wave absorbing surface 21 absorbs the unnecessary electromagnetic wave radiated in the horizontal direction to the maximum, and the electromagnetic wave absorbing surface 22 is inclined 45 with respect to the horizontal direction. Unwanted electromagnetic waves radiated at an angle of degrees can be absorbed to the maximum, and the electromagnetic wave absorbing surface 23 can absorb the unnecessary electromagnetic waves radiated in the vertical direction to the maximum.
一方、不要電磁波発生箇所１１ａが、プリント基板１０に敷設された伝送ライン１１上にあるとすると、このような中空構造によって、電磁波吸収体２０の媒質を伝送ライン１１から一定距離を離すことができるので、伝送ライン１１を流れる伝送信号に対しても影響を与えることはない。
On the other hand, if the unnecessary electromagnetic wave generation location 11a is on the transmission line 11 laid on the printed circuit board 10, the medium of the electromagnetic wave absorber 20 can be separated from the transmission line 11 by such a hollow structure. Therefore, the transmission signal flowing through the transmission line 11 is not affected.
なお、電磁波吸収体２０の不要電磁波吸収率をさらに高めるためには、電磁波吸収体２０の媒質の厚みを所要の厚みにする。例えば、プリント基板１０において、１０ＧＨｚの信号伝送を行う場合では、厚みｄを最低３ｍｍとなるように、電磁波吸収体２０を加工する（厚みの算出方法について後述する）。
In addition, in order to further increase the unnecessary electromagnetic wave absorption rate of the electromagnetic wave absorber 20, the thickness of the medium of the electromagnetic wave absorber 20 is set to a required thickness. For example, when 10 GHz signal transmission is performed on the printed circuit board 10, the electromagnetic wave absorber 20 is processed so that the thickness d is at least 3 mm (a method for calculating the thickness will be described later).
図２は中空構造が異なる電磁波吸収体の不要電磁波吸収効果の違いを示す図である。中空構造が四角形（コの字型）の電磁波吸収体２００では、不要電磁波発生箇所１１ａから斜め４５度に輻射した不要電磁波は、電磁波吸収体２００の媒質に対して垂直入射しないので吸収率が落ちることになる。このため、中空構造の内部での不要電磁波の反射率が高まり、電磁波吸収体２００とプリント基板１０との設置面の隙間から不要電磁波が漏洩しやすくなる。
FIG. 2 is a diagram showing the difference in the effect of absorbing unnecessary electromagnetic waves of electromagnetic wave absorbers having different hollow structures. In the electromagnetic wave absorber 200 having a square (U-shaped) hollow structure, the electromagnetic wave radiated at an angle of 45 degrees from the unnecessary electromagnetic wave generation site 11a does not vertically enter the medium of the electromagnetic wave absorber 200, and thus the absorption rate decreases. It will be. For this reason, the reflectance of the unnecessary electromagnetic wave inside the hollow structure is increased, and the unnecessary electromagnetic wave is likely to leak from the gap between the installation surfaces of the electromagnetic wave absorber 200 and the printed board 10.
これに対し、図１に示した電磁波吸収体２０では、不要電磁波発生箇所１１ａから斜め４５度に輻射した不要電磁波に対しても、電磁波吸収体２０の媒質に対して垂直入射することになるので、電磁波吸収体２００と比べて中空構造の内部での不要電磁波の反射率を低減することができる。このため、電磁波吸収体２０とプリント基板１０との設置面の隙間から不要電磁波が漏洩することを防止することが可能になる。
On the other hand, in the electromagnetic wave absorber 20 shown in FIG. 1, even an unnecessary electromagnetic wave radiated at an angle of 45 degrees from the unnecessary electromagnetic wave generation location 11 a is perpendicularly incident on the medium of the electromagnetic wave absorber 20. Compared with the electromagnetic wave absorber 200, the reflectance of unnecessary electromagnetic waves inside the hollow structure can be reduced. For this reason, it is possible to prevent unnecessary electromagnetic waves from leaking from the gap between the installation surfaces of the electromagnetic wave absorber 20 and the printed circuit board 10.
次に中空構造を半円球構造とした電磁波吸収体を設置した通信モジュールについて説明する。図３はプリント基板上に電磁波吸収体が設置されている通信モジュールを示す図である。通信モジュール１ａは、プリント基板１０と電磁波吸収体２０ａを備える。
Next, a communication module provided with an electromagnetic wave absorber having a hollow structure with a semispherical structure will be described. FIG. 3 is a diagram showing a communication module in which an electromagnetic wave absorber is installed on a printed board. The communication module 1a includes a printed circuit board 10 and an electromagnetic wave absorber 20a.
電磁波吸収体２０ａは、プリント基板１０上で不要電磁波が発生する不要電磁波発生箇所１１ａを覆うように、プリント基板１０に設置して、不要電磁波の吸収を行う。また、電磁波吸収体２０ａは、不要電磁波が電磁波吸収体２０ａの媒質に垂直入射するような中空構造を有しており、具体的には、この中空構造は半円球構造をとる。
The electromagnetic wave absorber 20a is installed on the printed circuit board 10 so as to cover the unnecessary electromagnetic wave generation site 11a where the unnecessary electromagnetic wave is generated on the printed circuit board 10, and absorbs the unnecessary electromagnetic wave. The electromagnetic wave absorber 20a has a hollow structure in which unnecessary electromagnetic waves are perpendicularly incident on the medium of the electromagnetic wave absorber 20a. Specifically, the hollow structure has a hemispherical structure.
このように、不要電磁波発生箇所１１ａを、半円球構造とした電磁波吸収体２０ａの空間で覆うことで、この空間内の電磁波吸収面に対しては、不要電磁波発生箇所１１ａから輻射されるすべての不要電磁波の入射角度が垂直となるため、吸収効率を最大にすることが可能になる。
In this way, by covering the unnecessary electromagnetic wave generation location 11a with the space of the electromagnetic wave absorber 20a having a semi-spherical structure, the electromagnetic wave absorbing surface in this space is all radiated from the unnecessary electromagnetic wave generation location 11a. Since the incident angle of the unnecessary electromagnetic wave becomes vertical, the absorption efficiency can be maximized.
また、不要電磁波発生箇所１１ａは、プリント基板１０に敷設された伝送ライン１１上にあるとすると、このような中空構造によって、電磁波吸収体２０ａの媒質を伝送ライン１１から一定距離を離すことができるので、伝送ライン１１を流れる伝送信号に対しても影響を与えることはない。
Further, assuming that the unnecessary electromagnetic wave generation site 11a is on the transmission line 11 laid on the printed circuit board 10, the medium of the electromagnetic wave absorber 20a can be separated from the transmission line 11 by a certain distance by such a hollow structure. Therefore, the transmission signal flowing through the transmission line 11 is not affected.
なお、図４に電磁波吸収体２０ａの概観を示す。また、図３、図４では電磁波吸収体２０ａの外形を四角形としたが、図５に示す電磁波吸収体２０ａ－１のように外形を半円球にしてもよい。
FIG. 4 shows an overview of the electromagnetic wave absorber 20a. 3 and 4, the outer shape of the electromagnetic wave absorber 20a is rectangular, but the outer shape may be a semispherical shape like the electromagnetic wave absorber 20a-1 shown in FIG.
次に中空構造を半円筒構造とした電磁波吸収体を設置した通信モジュールについて説明する。図６はプリント基板上に電磁波吸収体が設置されている通信モジュールを示す図である。通信モジュール１ｂは、プリント基板１０と電磁波吸収体２０ｂを備える。
Next, a communication module provided with an electromagnetic wave absorber having a hollow structure and a semi-cylindrical structure will be described. FIG. 6 is a diagram showing a communication module in which an electromagnetic wave absorber is installed on a printed board. The communication module 1b includes a printed circuit board 10 and an electromagnetic wave absorber 20b.
電磁波吸収体２０ｂは、プリント基板１０上で不要電磁波が発生する不要電磁波発生箇所１１ａ、１１ｂを覆うように、プリント基板１０に設置して不要電磁波の吸収を行う。また、電磁波吸収体２０ｂは、不要電磁波が電磁波吸収体２０ｂの媒質に垂直入射するような中空構造を有し、この中空構造は半円筒構造をとる。
The electromagnetic wave absorber 20b is installed on the printed circuit board 10 so as to cover the unnecessary electromagnetic wave generation portions 11a and 11b where unnecessary electromagnetic waves are generated on the printed circuit board 10, and absorbs the unnecessary electromagnetic waves. The electromagnetic wave absorber 20b has a hollow structure in which unnecessary electromagnetic waves are perpendicularly incident on the medium of the electromagnetic wave absorber 20b. The hollow structure has a semi-cylindrical structure.
伝送ライン１１において、近接した位置に複数の不要電磁波の発生箇所が長手方向にあるような場合には、その複数の不要電磁波発生箇所を覆うように、中空構造を半円筒構造とした電磁波吸収体２０ｂが有効である。
In the transmission line 11, when there are a plurality of unnecessary electromagnetic wave generation points in the longitudinal direction at close positions, the electromagnetic wave absorber having a hollow structure with a semi-cylindrical structure so as to cover the plurality of unnecessary electromagnetic wave generation points 20b is effective.
このように、不要電磁波発生箇所１１ａ、１１ｂを、中空構造を半円筒構造とした電磁波吸収体２０ｂの空間で覆うことで、不要電磁波発生箇所１１ａ、１１ｂから輻射されるすべての不要電磁波の入射角度が垂直となるため、吸収効率を最大にすることが可能になる。
Thus, the incident angle of all the unnecessary electromagnetic waves radiated from the unnecessary electromagnetic wave generation points 11a and 11b is obtained by covering the unnecessary electromagnetic wave generation points 11a and 11b with the space of the electromagnetic wave absorber 20b having a hollow cylindrical structure. Since it becomes vertical, the absorption efficiency can be maximized.
また、不要電磁波発生箇所１１ａ、１１ｂは、プリント基板１０に敷設された伝送ライン１１上にあるが、このような中空構造によって、電磁波吸収体２０ｂの媒質を伝送ライン１１から一定距離を離すことができるので、伝送ライン１１を流れる伝送信号に対しても影響を与えることはない。
The unnecessary electromagnetic wave generation points 11a and 11b are on the transmission line 11 laid on the printed circuit board 10. However, the hollow structure allows the medium of the electromagnetic wave absorber 20b to be separated from the transmission line 11 by a certain distance. Therefore, the transmission signal flowing through the transmission line 11 is not affected.
なお、図６では、１本の伝送ライン１１による単相伝送において、中空が半円筒構造の電磁波吸収体２０ｂを設置してＥＭＩ抑制を行っているが、２本の伝送ラインによる差動伝送においても、同様にして、不要電磁波発生箇所に電磁波吸収体２０ｂを設置すれば、ＥＭＩの抑制を行うことができる。
In FIG. 6, in the single-phase transmission by one transmission line 11, the electromagnetic wave absorber 20 b having a hollow semi-cylindrical structure is installed to suppress EMI, but in the differential transmission by two transmission lines. Similarly, EMI can be suppressed by installing the electromagnetic wave absorber 20b at the location where the unnecessary electromagnetic wave is generated.
次に電磁波吸収体２０の厚みｄの算出方法について説明する。電磁波吸収体２０の複素比誘電率εrは、式（１）で表せる。なお、εaは実数部の誘電率、εbは複素数部の誘電率である。
Next, a method for calculating the thickness d of the electromagnetic wave absorber 20 will be described. The complex relative dielectric constant ε r of the electromagnetic wave absorber 20 can be expressed by Expression (1). Ε a is the dielectric constant of the real part, and ε b is the dielectric constant of the complex part.
εr＝εa－ｊεb・・・（１）
ここで、電磁波吸収体の所要損失レベルを２０ｄＢとした場合、電磁波吸収体の厚みｄのパラメータを含む式は、以下の式（２）となる。 ε r = ε a −jε b (1)
Here, when the required loss level of the electromagnetic wave absorber is 20 dB, the equation including the parameter of the thickness d of the electromagnetic wave absorber is the following equation (2).
ここで、電磁波吸収体の所要損失レベルを２０ｄＢとした場合、電磁波吸収体の厚みｄのパラメータを含む式は、以下の式（２）となる。 ε r = ε a −jε b (1)
Here, when the required loss level of the electromagnetic wave absorber is 20 dB, the equation including the parameter of the thickness d of the electromagnetic wave absorber is the following equation (2).
λは波長、ｄは電磁波吸収体の厚みである。また、tanh（x）＝sinh（x）／cosh（x）であり、sinh（x）＝（ｅx－ｅ-x）／２、cosh（x）＝（ｅx＋ｅ-x）／２である。また、εa＝６．６５、εb＝３．１５となるとき（これらεa、εbの値は定数である）、式（１）からεrが算出される。そして、式（２）に対して、εrを代入して、ｄ／λ＝０．１が求められる。
λ is the wavelength, and d is the thickness of the electromagnetic wave absorber. Further, a tanh (x) = sinh (x ) / cosh (x), with sinh (x) = (e x -e -x) / 2, cosh (x) = (e x + e -x) / 2 is there. When ε a = 6.65 and ε b = 3.15 (the values of ε a and ε b are constants), ε r is calculated from the equation (1). Then, by substituting ε r into equation (2), d / λ = 0.1 is obtained.
一方、ｆを周波数、ｃを光速とした場合、ｃ＝ｆ・λなので、ｆ＝１０ＧＨｚ、ｃ＝３×１０8ｍ／ｓとすれば、λ＝３ｃｍ＝（３×１０8）／（１０×１０9）となる。したがって、ｄ／λ＝０．１であるから、ｄ＝０．１×λ＝０．１×３ｃｍ＝３ｍｍと求まる。すなわち、電磁波の周波数が１０ＧＨｚであって、損失レベルを２０ｄＢとする場合には、電磁波吸収体の厚みを３ｍｍとすればよいことになる。
On the other hand, when f is the frequency and c is the speed of light, since c = f · λ, if f = 10 GHz and c = 3 × 10 8 m / s, then λ = 3 cm = (3 × 10 8 ) / (10 × 10 9 ). Therefore, since d / λ = 0.1, d = 0.1 × λ = 0.1 × 3 cm = 3 mm. That is, when the frequency of the electromagnetic wave is 10 GHz and the loss level is 20 dB, the thickness of the electromagnetic wave absorber may be 3 mm.
なお、電磁波吸収体への不要電磁波の入射方向と垂直軸とのなす角度をθとすると（図３のθを参照）、上述の式（２）は、θ＝０、すなわち、不要電磁波が電磁波吸収体に対して垂直入射した場合の式である。電磁波吸収体への入射角度が垂直軸に対してθの角度がある場合は、以下の式（２ａ）が用いられることになる。
If the angle between the incident direction of the unnecessary electromagnetic wave on the electromagnetic wave absorber and the vertical axis is θ (see θ in FIG. 3), the above equation (2) is θ = 0, that is, the unnecessary electromagnetic wave is an electromagnetic wave. This is a formula in the case of normal incidence to the absorber. When the incident angle to the electromagnetic wave absorber is θ with respect to the vertical axis, the following equation (2a) is used.
以上説明したように、電磁波吸収体の中空構造を、不要電磁波が垂直入射する電磁波吸収面を備えた構造とした。これにより、主信号に影響を与えずに、効率よくＥＭＩの抑制を行うことが可能になる。
As described above, the hollow structure of the electromagnetic wave absorber has a structure including an electromagnetic wave absorbing surface on which unnecessary electromagnetic waves are vertically incident. As a result, it is possible to efficiently suppress EMI without affecting the main signal.
上記については単に本発明の原理を示すものである。さらに、多数の変形、変更が当業者にとって可能であり、本発明は上記に示し、説明した正確な構成および応用例に限定されるものではなく、対応するすべての変形例および均等物は、添付の請求項およびその均等物による本発明の範囲とみなされる。
The above merely shows the principle of the present invention. In addition, many modifications and changes can be made by those skilled in the art, and the present invention is not limited to the precise configuration and application shown and described above, and all corresponding modifications and equivalents may be And the equivalents thereof are considered to be within the scope of the invention.
１ 通信モジュール
１０ プリント基板
１１ 伝送ライン
１１ａ 不要電磁波発生箇所
２０ 電磁波吸収体
２１～２３ 電磁波吸収面
ｄ 厚み DESCRIPTION OFSYMBOLS 1 Communication module 10 Printed circuit board 11 Transmission line 11a Unnecessary electromagnetic wave generation location 20 Electromagnetic wave absorber 21-23 Electromagnetic wave absorption surface d Thickness
１０ プリント基板
１１ 伝送ライン
１１ａ 不要電磁波発生箇所
２０ 電磁波吸収体
２１～２３ 電磁波吸収面
ｄ 厚み DESCRIPTION OF
Claims (7)
- プリント基板と、
前記プリント基板上で不要電磁波が発生する不要電磁波発生箇所を覆って、前記不要電磁波を吸収する電磁波吸収体と、
を備え、
前記電磁波吸収体は、前記不要電磁波が垂直入射する電磁波吸収面を備えた中空構造を有する、
ことを特徴とする通信モジュール。 A printed circuit board,
An electromagnetic wave absorber that covers the unnecessary electromagnetic wave generation point where the unnecessary electromagnetic wave is generated on the printed board, and absorbs the unnecessary electromagnetic wave,
With
The electromagnetic wave absorber has a hollow structure provided with an electromagnetic wave absorbing surface on which the unnecessary electromagnetic waves are perpendicularly incident.
A communication module characterized by that. - 前記電磁波吸収体は、
前記不要電磁波発生箇所から水平方向に輻射した前記不要電磁波が垂直入射する第１の電磁波吸収面と、
前記不要電磁波発生箇所から水平方向に対して斜め４５度の角度で輻射した前記不要電磁波が垂直入射する第２の電磁波吸収面と、
前記不要電磁波発生箇所から垂直方向に輻射した前記不要電磁波が垂直入射する第３の電磁波吸収面と、
を備えた前記中空構造を有することを特徴とする請求の範囲第１項記載の通信モジュール。 The electromagnetic wave absorber is
A first electromagnetic wave absorbing surface on which the unnecessary electromagnetic wave radiated in a horizontal direction from the unnecessary electromagnetic wave generation site is vertically incident;
A second electromagnetic wave absorbing surface on which the unnecessary electromagnetic wave radiated at an angle of 45 degrees obliquely with respect to the horizontal direction from the unnecessary electromagnetic wave generation point is vertically incident;
A third electromagnetic wave absorbing surface on which the unnecessary electromagnetic wave radiated in a vertical direction from the unnecessary electromagnetic wave generation point is vertically incident;
The communication module according to claim 1, wherein the communication module has the hollow structure. - 前記電磁波吸収体は、半円球形状の前記電磁波吸収面を備えた前記中空構造を有することを特徴とする請求の範囲第１項記載の通信モジュール。 The communication module according to claim 1, wherein the electromagnetic wave absorber has the hollow structure provided with the semi-spherical electromagnetic wave absorbing surface.
- 前記電磁波吸収体は、半円筒形状の前記電磁波吸収面を備えた前記中空構造を有することを特徴とする請求の範囲第１項記載の通信モジュール。 The communication module according to claim 1, wherein the electromagnetic wave absorber has the hollow structure provided with the semi-cylindrical electromagnetic wave absorbing surface.
- 電磁波を吸収する電磁波吸収体において、
前記電磁波が垂直入射する電磁波吸収面を備えた中空構造を有して、前記電磁波が発生する電磁波発生箇所を覆い、
前記中空構造は、前記電磁波発生箇所から水平方向に輻射した前記電磁波が垂直入射する第１の電磁波吸収面と、前記電磁波発生箇所から水平方向に対して斜め４５度の角度で輻射した前記電磁波が垂直入射する第２の電磁波吸収面と、前記電磁波発生箇所から垂直方向に輻射した前記電磁波が垂直入射する第３の電磁波吸収面とを備える、
ことを特徴とする電磁波吸収体。 In an electromagnetic wave absorber that absorbs electromagnetic waves,
It has a hollow structure with an electromagnetic wave absorbing surface on which the electromagnetic wave is perpendicularly incident, and covers an electromagnetic wave generation location where the electromagnetic wave is generated,
The hollow structure includes a first electromagnetic wave absorbing surface on which the electromagnetic wave radiated in a horizontal direction from the electromagnetic wave generation site is vertically incident, and the electromagnetic wave radiated from the electromagnetic wave generation site at an oblique angle of 45 degrees with respect to the horizontal direction. A second electromagnetic wave absorbing surface that is perpendicularly incident, and a third electromagnetic wave absorbing surface on which the electromagnetic wave radiated in a vertical direction from the electromagnetic wave generation site is vertically incident.
An electromagnetic wave absorber characterized by that. - 電磁波を吸収する電磁波吸収体において、
前記電磁波が垂直入射する電磁波吸収面を備えた中空構造を有し、
前記中空構造は、半円球構造である、
ことを特徴とする電磁波吸収体。 In an electromagnetic wave absorber that absorbs electromagnetic waves,
A hollow structure provided with an electromagnetic wave absorbing surface on which the electromagnetic wave is vertically incident,
The hollow structure is a hemispherical structure,
An electromagnetic wave absorber characterized by that. - 電磁波を吸収する電磁波吸収体において、
前記電磁波が垂直入射する電磁波吸収面を備えた中空構造を有し、
前記中空構造は、半円筒構造である、
ことを特徴とする電磁波吸収体。 In an electromagnetic wave absorber that absorbs electromagnetic waves,
A hollow structure provided with an electromagnetic wave absorbing surface on which the electromagnetic wave is vertically incident,
The hollow structure is a semi-cylindrical structure,
An electromagnetic wave absorber characterized by that.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2009/056547 WO2010116463A1 (en) | 2009-03-30 | 2009-03-30 | Communication module |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2009/056547 WO2010116463A1 (en) | 2009-03-30 | 2009-03-30 | Communication module |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2010116463A1 true WO2010116463A1 (en) | 2010-10-14 |
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ID=42935774
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2009/056547 WO2010116463A1 (en) | 2009-03-30 | 2009-03-30 | Communication module |
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| Country | Link |
|---|---|
| WO (1) | WO2010116463A1 (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01158797A (en) * | 1987-12-15 | 1989-06-21 | Matsushita Electric Works Ltd | Movable radio-wave absorber |
| JPH0343800U (en) * | 1989-09-04 | 1991-04-24 | ||
| JPH1079589A (en) * | 1996-07-10 | 1998-03-24 | Yoshio Yamamoto | Noise absorbing device |
| JPH10303591A (en) * | 1997-04-30 | 1998-11-13 | Matsushita Electric Works Ltd | Electromagnetic wave preventing structure for electronic apparatus |
| JP2000124482A (en) * | 1998-10-20 | 2000-04-28 | Fujitsu Ltd | Optical module |
| JP2003124011A (en) * | 2001-10-09 | 2003-04-25 | Hitachi Ltd | Electromagnetic wave absorber and product using the same |
| JP2007324317A (en) * | 2006-05-31 | 2007-12-13 | Toshiba Corp | Emi shield device, emi shield ic package, and electronic device |
-
2009
- 2009-03-30 WO PCT/JP2009/056547 patent/WO2010116463A1/en active Application Filing
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01158797A (en) * | 1987-12-15 | 1989-06-21 | Matsushita Electric Works Ltd | Movable radio-wave absorber |
| JPH0343800U (en) * | 1989-09-04 | 1991-04-24 | ||
| JPH1079589A (en) * | 1996-07-10 | 1998-03-24 | Yoshio Yamamoto | Noise absorbing device |
| JPH10303591A (en) * | 1997-04-30 | 1998-11-13 | Matsushita Electric Works Ltd | Electromagnetic wave preventing structure for electronic apparatus |
| JP2000124482A (en) * | 1998-10-20 | 2000-04-28 | Fujitsu Ltd | Optical module |
| JP2003124011A (en) * | 2001-10-09 | 2003-04-25 | Hitachi Ltd | Electromagnetic wave absorber and product using the same |
| JP2007324317A (en) * | 2006-05-31 | 2007-12-13 | Toshiba Corp | Emi shield device, emi shield ic package, and electronic device |
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