JP4440002B2 - Anechoic chamber - Google Patents

Description

  The present invention relates to an anechoic chamber, and more particularly, an anechoic chamber configured by forming an electromagnetic wave absorber including an electromagnetic wave absorbing member on the inner surface of an electromagnetic shield chamber, in which an electronic device or the like is tested. The present invention relates to an anechoic chamber in which various characteristics of the body are evaluated.

  Conventionally, evaluation of radiated electromagnetic waves from electronic devices, evaluation of electromagnetic compatibility, evaluation of transmission / reception characteristics of antennas, and the like have been performed in an anechoic chamber using an anechoic chamber.

  FIG. 1 is a schematic configuration diagram illustrating a part of such a conventional anechoic chamber, in which a radiated electromagnetic wave from an electronic device is evaluated in the anechoic chamber.

  As shown in FIG. 1, the anechoic chamber 100 includes an electromagnetic shield chamber 102 shielded from the outside.

  The electromagnetic shield chamber 102 includes a surface 104a of the floor 104 having electromagnetic shielding properties, a front electromagnetic shield wall 106a erected on the surface 104a of the floor 104, and a rear electromagnetic shield wall erected on the surface 104a of the floor 104. 106b, a left electromagnetic shield wall 106c erected on the surface 104a of the floor 104, a right electromagnetic shield wall 106d erected on the surface 104a of the floor 104, a left electromagnetic shield wall 106a, a rear electromagnetic shield wall 106b, and a left side This space is shielded from the outside by the upper electromagnetic shield wall 106e disposed on the upper surfaces of the electromagnetic shield wall 106c and the right electromagnetic shield wall 106d.

  On the inner surface of the electromagnetic shielding chamber 102, that is, the surface 104a of the floor 104, the front electromagnetic shielding wall 106a, the rear electromagnetic shielding wall 106b, the left electromagnetic shielding wall 106c, the right electromagnetic shielding wall 106d, and the upper electromagnetic shielding wall 106e, A radio wave absorber 108 including a radio wave absorbing member is provided.

  Further, a cable outlet 110 that connects the inside and the outside of the electromagnetic shield chamber 102 is formed at the lower part of the left electromagnetic shield wall 106c and the radio wave absorber 108 disposed on the left electromagnetic shield wall 106c.

  On the radio wave absorber 108 formed on the surface 104a of the floor 104 in the electromagnetic shield chamber 102, a first support 114 for supporting an electronic device 112 as a transmitting / receiving device as a test object and a measurement antenna 116 are provided. And a second support stand 118 for supporting the. The electronic device 112 and the antenna 116 are supported by the first support base 114 and the second support base 118 at predetermined positions and postures, respectively. Note that the vertical position of the antenna 116 can be variably set along the second support base 118 so that the characteristics of radio waves radiated from the electronic device 112 can be evaluated at various height positions. Has been made.

  Here, the flexible cable 120 connected to the antenna 116 hangs down from the connecting portion 116a at the rear end of the antenna 116 toward the surface 104a of the floor 104 in the electromagnetic shield chamber 102 immediately after the antenna 116, and crawls the surface 104a. And extended to the outside of the anechoic chamber 100 through the cable outlet 110 and connected to the characteristic measuring device 122. The flexible cable 120 is made of a coaxial cable, for example.

In the above configuration, the electromagnetic wave radiated from the electronic device 112 is received by the antenna 116 as, for example, horizontal / vertically polarized waves, and this characteristic is evaluated by the characteristic measuring device 122. Alternatively, radio waves are radiated from the antenna 116, and changes in the operation of the electronic device 112 are evaluated.

However, in the conventional anechoic chamber described above, there is only a normal air-conditioning facility that performs air-conditioning management of the entire electromagnetic shield room in which the electromagnetic wave absorber including the electromagnetic wave absorbing member is arranged, and the surroundings of the transmission / reception device that is the test object There is a problem that the temperature cannot be kept constant, and there is a possibility of affecting the temperature characteristic evaluation by the electromagnetic wave radiated or received from the transmitting / receiving device.

  In addition, although a thermostat is known as a device that keeps the ambient temperature constant, such a thermostat is only a metal one that affects the electromagnetic waves radiated from the transmitting and receiving equipment that is the device under test. It could not be used in an anechoic chamber.

The prior art that the applicant of the present application knows at the time of filing a patent is as described above and is not an invention related to a known literature, so there is no prior art information to be described.

  The present invention has been made in view of the various problems of the conventional techniques as described above, and the object of the present invention is in an electromagnetic shield room in which a radio wave absorber including a radio wave absorber is provided. An attempt is made to provide an anechoic chamber in which the ambient temperature of the device under test can be kept constant, and the influence on the temperature characteristic evaluation due to electromagnetic waves radiated or received from the device under test can be reduced. Is.

  In order to achieve the above object, the anechoic chamber according to the present invention surrounds a device under test with a cover provided with an air circulation duct in an electromagnetic shield room provided with a radio wave absorber including a radio wave absorbing member. The ambient temperature of the device under test can be kept constant at an arbitrary temperature, and the end of the air circulation duct opens to the outside of the anechoic chamber.

  According to such an anechoic chamber according to the present invention, the ambient temperature of the device under test can be kept constant, and the influence on the temperature characteristic evaluation due to the electromagnetic waves radiated or received from the device under test can be reduced. It becomes like this.

  Further, according to the anechoic chamber according to the present invention, since there is no need to install a thermostatic chamber in the anechoic chamber, there is no need to consider the influence of the thermostatic chamber on the electromagnetic wave radiated from the test object.

  Therefore, if the anechoic chamber according to the present invention is used, the temperature characteristics of the DUT can be measured easily and inexpensively in the anechoic chamber.

  Here, it is preferable that the cover surrounding the device under test and the air circulation duct be formed of a material that does not affect electromagnetic waves.

  Examples of such a material that does not affect electromagnetic waves include foamed polystyrene and resin, and may be appropriately selected. For example, a cover can be formed of foamed polystyrene, and an air circulation duct can be formed of resin.

  In addition, the air circulation duct has a temperature setting at the end of the air circulation duct that opens to the outside of the anechoic chamber so that air of any temperature can be forcibly circulated in the transmission / reception device cover by the air circulation duct. It is preferable to connect an air conditioning facility that can arbitrarily perform the above.

  As such air conditioning equipment, conventionally known air conditioning equipment can be appropriately used.

That is, the invention according to claim 1 of the present invention is an anechoic chamber in which an electromagnetic wave absorber including an electromagnetic wave absorbing member is formed on the inner surface of an electromagnetic shield chamber, and the anechoic chamber has a passage communicating with the outside. The anechoic chamber has a cover that surrounds the entire DUT except for a single cover opening, and extends through the passage to the inside and outside of the anechoic chamber. parts as well as connected to cover an opening formed in the cover, the other open end and a one duct for air circulation which is connected to the air conditioning equipment provided outside of the anechoic chamber, the air circulation The duct is divided into a double structure, and an intake duct for introducing air from outside the anechoic chamber into the cover and air inside the cover to the outside of the anechoic chamber. Waste to send An air duct is formed, and air at an arbitrary temperature is circulated in the cover through the air circulation duct by the air conditioning equipment, and the temperature in the cover and the air circulation duct can be changed. It was possible to maintain at a constant temperature .

  The invention according to claim 2 of the present invention is the invention according to claim 1 of the present invention, wherein the cover and the air circulation duct are formed of a material that does not affect electromagnetic waves. It is what I did.

The invention according to claim 3 of the present invention is the invention according to claim 2 of the present invention, wherein the cover and the air circulation duct are formed of a material having good heat retention. It is what you have.

  According to the present invention, since the ambient temperature of the transmitting / receiving device, which is the device under test, can be kept constant in the electromagnetic shield room in which the wave absorber including the radio wave absorbing member is disposed, It is possible to reduce the influence on the temperature characteristic evaluation due to electromagnetic waves radiated or received from a certain transmitting / receiving device, and it is possible to provide an anechoic chamber that can easily measure the temperature characteristic of the DUT at a low cost. There is an excellent effect.

  Hereinafter, an example of an embodiment of an anechoic chamber according to the present invention will be described in detail with reference to the accompanying drawings.

  2 to 5, the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals as those used in FIG.

FIG. 2 is a schematic configuration explanatory view corresponding to FIG. 1 in which a part of an anechoic chamber according to an embodiment of the present invention is cut away, and radiated electromagnetic waves from electronic devices in the anechoic chamber are shown. The case where it evaluates is shown.

  The anechoic chamber 10 according to the present invention shown in FIG. 2 includes a cover 12 that encloses an entire electronic device 112 that is a transmission / reception device that is a device under test, and an air that is connected to a cover opening 14 formed in a part of the cover 12. It differs from the conventional anechoic chamber 100 in that it has a circulation duct 16.

  Here, it is preferable that the cover 12 and the air circulation duct 16 are made of a material having good heat retention without affecting electromagnetic waves. Examples of the material having good heat retention without affecting the electromagnetic wave include foamed polystyrene and resin. The cover 12 is formed on the foamed polystyrene, and the air circulation duct 16 can be formed of the resin.

  In addition, a passage 18 that communicates the inside and the outside of the electromagnetic shield chamber 102 is formed under the right electromagnetic shield wall 106d and the radio wave absorber 108 disposed on the right electromagnetic shield wall 106d. The air circulation duct 16 including the duct 16a and the exhaust duct 16b extends through the passage 18 over the inside and the outside of the anechoic chamber 10, and one open end of the intake duct 16a and the exhaust duct 16b. This part is connected to a cover opening 14 formed in the cover 12, and the other opening end of the intake duct 16 a and the exhaust duct 16 b is opened outside the anechoic chamber 10.

  An air conditioner 20 capable of changing the set temperature is installed outside the anechoic chamber 10, and the other opening end portions of the intake duct 16a and the exhaust duct 16b that are open outside the anechoic chamber 10 are: The air conditioner 20 is connected.

  By operating the air conditioning equipment 20, the air sent from the air conditioning equipment 20 through the intake duct 16a is introduced into the cover 12, and the air in the cover 12 is sent to the air conditioning equipment 20 through the exhaust duct 16b. Sent out. In this way, the air in the air circulation duct 16 constituted by the cover 12, the intake duct 16a, and the exhaust duct 16b is forcibly circulated, and the cover 12, the intake duct 16a, the exhaust duct 16b, The temperature in the air circulation duct 16 constituted by can be changed and can be maintained at an arbitrary constant temperature.

In the above configuration, in the anechoic chamber 10, when the air conditioning equipment 20 is operated so that the set temperature becomes a predetermined arbitrary temperature, the air duct 16 a and the exhaust duct 16 b cover the air circulation duct 16. The air inside the cover 12 is forcibly circulated, and the inside of the cover 12 is brought into an equilibrium state in a short time at the predetermined arbitrary temperature, and can be kept constant at the predetermined arbitrary temperature.

  Therefore, in the anechoic chamber 10, the ambient temperature of the electronic device 112, which is a wave transmitting / receiving device as a device under test, can be kept constant in the electromagnetic shield chamber 102 in which the radio wave absorber 108 including the radio wave absorbing member is disposed. Therefore, it becomes possible to reduce the influence on the temperature characteristic evaluation due to the electromagnetic wave radiated or received from the electronic device 112, and to improve the temperature characteristic measurement accuracy of the radio wave transmitted and received in the electronic device 112. Is possible. For this reason, the temperature characteristic of the electronic device 112 can be easily measured at low cost. For example, the temperature characteristic of the radiated EMI of the electronic device 112 can be measured at low cost and with higher accuracy.

  That is, according to the anechoic chamber 10, it is possible to improve the accuracy of measuring the temperature characteristics of radio waves transmitted and received by the electronic device 112 as a transmitting / receiving device as a device under test in the anechoic chamber 10.

In the above-described embodiment, the intake duct 16a and the exhaust duct 16b constituting the air circulation duct 16 are shown in FIG. 3 , and the intake duct 16a and the exhaust duct 16b are one in appearance. However, it may be a double-structured duct divided inside.

  INDUSTRIAL APPLICABILITY The present invention can be used when evaluating radiated electromagnetic waves from a transmitting / receiving device such as an electronic device, evaluating electromagnetic compatibility, and evaluating transmission / reception characteristics of an antenna.

It is schematic structure explanatory drawing which fractured and showed a part of conventional anechoic chamber, and has shown the case where the radiation electromagnetic wave from an electronic device is evaluated in an anechoic chamber. FIG. 2 is a schematic configuration explanatory view corresponding to FIG. 1 in which a part of an anechoic chamber according to an embodiment of the present invention is cut away, and shows a case where an electromagnetic wave radiated from an electronic device is evaluated in the anechoic chamber. It is a perspective view which shows a cover and a part of duct for air circulation.

Explanation of symbols

10, 100 Anechoic chamber 12 Cover 12
14 Cover opening 16 Air circulation duct 16a Intake duct 16b Exhaust duct 18 Passage 20 Air conditioning equipment 102 Electromagnetic shield room 104 Floor 104a Surface 106a Front electromagnetic shield wall 106b Rear electromagnetic shield wall 106c Left electromagnetic shield wall 106d Right electromagnetic shield wall 106e Upper electromagnetic shield wall 108 Radio wave absorber 110 Cable outlet 112 Electronic device 114 First support stand 116 Antenna 118 Second support stand 120 Flexible cable 122 Characteristic measuring instrument

Claims (3)

An anechoic chamber in which an electromagnetic wave absorber including an electromagnetic wave absorbing member is formed on the inner surface of the electromagnetic shield room,
The anechoic chamber has a passage communicating with the outside,
In the anechoic chamber,
A cover that surrounds the entire DUT except for a single cover opening;
It extends through the passage to the inside and outside of the anechoic chamber, one opening end is connected to a cover opening formed in the cover, and the other opening end is provided outside the anechoic chamber. One air circulation duct connected to the air conditioning facility
The air circulation duct has a double structure divided inside, and an intake duct for introducing air from the outside of the anechoic chamber into the inside of the cover, and the air inside the cover as the anechoic chamber And an exhaust duct for delivery to the outside of the
Air at an arbitrary temperature is circulated in the cover through the air circulation duct by the air conditioning equipment, and the temperature of the cover and the air circulation duct can be changed and maintained at an arbitrary constant temperature. An anechoic chamber characterized by In the anechoic chamber according to claim 1,
The anechoic chamber, wherein the cover and the air circulation duct are made of a material that does not affect electromagnetic waves. In the anechoic chamber according to claim 2,
The anechoic chamber, wherein the cover and the air circulation duct are made of a material having good heat retention .

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