JP2007183211A - Apparatus and method for measuring shielding performance of electromagnetic wave shielding door - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable even periodic measurement of the shielding performance of an electromagnetic wave shielding room during its operation, besides measurement after its installation. <P>SOLUTION: This measuring device is constituted by respectively providing a plurality of sets of transmitting antennas TX-1 to TX-n and receiving antennas RX-1 to RX-n located respectively on the inside-the-room side and the outside-the-room side of a shielding door 6 and installed facing each other, around the shielding door 6 installed at the doorway 5 of the electromagnetic shielding room, a transmitting part 1 and a receiving part 3 connected respectively to the transmitting antennas TX-1 to TX-n and the receiving antennas RX-1 to RX-n, a transmission switchover part 2 and a reception switchover part 4 connected respectively between the transmitting part 1 and the transmitting antennas TX-1 to TX-n, and between the receiving part 3 and the receiving antennas RX-1 to RX-n, and a supervisory controller for performing supervisory control of the functional operations of the transmitting part 1 and the receiving part 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for measuring shielding performance of an electromagnetic shielding door, and can periodically measure the shielding performance of a shielding door installed in an opening of an electromagnetic shielding room and monitor the deterioration status of a shielding gasket. .

  In general, a shield gasket is attached to both the outer periphery of the shield door installed at the entrance and exit of the shield room and the inner periphery of the entrance to prevent electromagnetic waves from leaking around the shield door when the shield door is closed. Yes.

  The shield gasket may be broken due to friction caused by opening and closing of the door, and in that case, the shield performance of the shield door is significantly lowered. In general, it is known that the factor that lowers the shield performance of the shield room is due to the deterioration of the shield gasket.

  Therefore, it is considered that the shield performance of the entire shield room can be maintained by periodically checking the shield performance of the shield door and refurbishing as necessary. However, the cost is generally high in terms of personnel costs.

  Conventionally, methods for measuring electromagnetic shielding performance in electromagnetic shielding rooms include MIL-STD285 and electromagnetic shielding room test methods established by related ministries and agencies, construction associations involved in the construction of electromagnetic shielding rooms and anechoic chambers, etc. Measurement methods that summarize the results of research conducted mainly by material and equipment manufacturers are known.

Japanese Patent No. 3664961 Registered utility model No. 003085506 Japanese Patent Publication No. 07-105612 PAMS shielding performance measuring instrument manual http://www.shoshin.co.jp/emi-emc/pams.html

  However, these measuring methods are methods for temporarily measuring the shielding performance after the electromagnetic shielding room is installed, and cannot be measured periodically during the operation of the shielding room.

  Although there is a method to periodically measure the electromagnetic shielding performance while using the shielded room after installing the electromagnetic shielding room, a highly accurate system specialized for monitoring the performance of the door in use has not yet been developed. Absent.

  The present invention has been made to solve the above problems, and in particular, not only after the installation of the electromagnetic shielding room, but also allows periodic measurement of the shielding performance during operation, thereby continuing the electromagnetic shielding room. An object of the present invention is to provide a shielding performance measuring device and a measuring method for an electromagnetic shielding door that can be operated.

  The apparatus for measuring shielding performance of an electromagnetic shielding door according to claim 1 is installed around the shielding door installed at the opening of the electromagnetic shielding room, on the indoor side and the outdoor side of the shielding door, and facing each other. A plurality of sets of transmission antennas and reception antennas, a transmission unit and a reception unit connected to the transmission antenna and the reception antenna, respectively, between the transmission antenna and the transmission unit, and between the reception antenna and the reception unit, respectively. The transmission control unit is configured to include a connected transmission switching unit and a reception switching unit, and a monitoring control unit that monitors and controls the functional operations of the transmission unit and the reception unit.

  The present invention provides a transmitting antenna for transmitting electromagnetic waves on the indoor side of a shield room and a receiving antenna for receiving the transmitted radio waves on the outdoor side of the shield room, respectively, and particularly in the vicinity of the shield door with the shield door closed. The shield performance of the shield room is evaluated by measuring electromagnetic waves leaking from the indoor side of the shield room to the outdoor side. In this case, a 1 GHz band radio wave can be used as the transmission radio wave.

  In the shield room, the leakage of electromagnetic waves is greatest around the shield door attached to the opening of the shield room, so the transmitting antenna and the receiving antenna are vertically and / or laterally on the opening side around the shield door. It is preferable to install a plurality of sets facing each other, particularly so as to cover the opening.

  The shielding performance measuring apparatus for an electromagnetic shielding door according to claim 2 is the shielding performance measuring apparatus for an electromagnetic shielding door according to claim 1, wherein the plurality of sets of transmitting antennas and receiving antennas are respectively in the vertical direction and / or lateral direction of the shielding door. It is characterized by being installed facing the direction.

  According to the present invention, the shield performance of each part is accurately measured by sequentially switching to a pair of transmission antennas and reception antennas arbitrarily selected from a plurality of pairs of transmission antennas and reception antennas, and transmitting and receiving electromagnetic waves. be able to.

  In addition, since the influence of the performance of each antenna and the radio wave propagation characteristics can be reduced, the performance measurement of the electromagnetic wave shield room is stable, and the shield performance of the shield door can be measured with high accuracy.

  The electromagnetic wave shielding door shielding performance measuring apparatus according to claim 3 is the electromagnetic wave shielding door shielding performance measuring apparatus according to claim 1, wherein the plurality of sets of transmitting antennas and receiving antennas are respectively in the vertical direction and / or lateral direction of the shield door. It is characterized by being installed so as to face each other and the opposite directions cross each other. According to the present invention, the shielding performance of the shield door is more accurate than the invention according to claim 2. Measurements can be made.

  The shielding performance measuring method of the electromagnetic shielding door according to claim 4 is a shielding performance measuring method for measuring the shielding performance of the shielding door installed in the opening of the electromagnetic shielding room, and the shielding door is opened in the state where the shielding door is opened. The transmission power for supplying the minimum reception power that can be recognized by the reception antenna for the transmission radio wave that propagates around the shield door, and the transmission radio wave that propagates around the shield door with the shield door closed The difference from the transmission power to supply the minimum received power that can be recognized by the antenna is the shielding performance (shielding effect) of the shield door, and the amount of reduction (degradation) of the shield performance is in the state where the shield door is closed. It is characterized by measuring.

  When measuring the shielding performance of the electromagnetic shielding door, measure the radio wave propagation characteristics (radio wave propagation loss in space) between the transmitting antenna and the receiving antenna with the shield door opened in advance. The transmission power at the time of the received power is assumed to be the reference value 1. This measurement of the reference value 1 is called system level calibration (FIG. 3 CALIBRATION section).

  Next, the radio wave propagation characteristics with the shield door closed (the characteristic at this time is a shielding effect) is measured, and the minimum received power that can be recognized by the receiving antenna (when the minimum received power is The transmission power is increased so that the reception power is equivalent), and the transmission power at that time is set to the reference value 2 (see FIG. 4).

  And the difference of these reference values 1 and 2 is calculated | required, and let this difference be the shielding performance (shielding effect) of a shield door. However, the transmission power is the lowest transmission power at which a stable characteristic (the power value of the minimum reception power) can be obtained at the reception unit.

  The reference value 1 need only be measured at the time of installation or during periodic inspection and maintenance. Normally, the reference value 2 is measured with the shield door closed, and each time the reference value 1 and reference value 2 are measured. The difference can be obtained, and the difference can be used as the shielding performance of the shield door.

  The shield performance value (difference between the reference value 1 and the reference value 2) of the electromagnetic shielding door can be measured periodically and the result can be stored in the storage circuit. In addition, when the shielding effect value exceeds a preset range, a function of notifying the operator that the shielding performance may be deteriorated is provided.

  In addition, the shielding effect value measured periodically is stored in the memory circuit, and at the same time, the mutual difference between the shielding effect value stored in the past is detected (difference between shielding effect values). It also has a function to notify the operator that there is a possibility that the shielding performance has deteriorated when the numerical value set in advance is exceeded.

  As a result, it is possible to detect the deterioration of the electromagnetic shielding performance from the stored measurement data and notify the operator in advance of the replacement timing of the shield gasket as an alarm when the degree of deterioration exceeds a certain criterion. It can be operated continuously.

  The monitoring control unit included in the receiving unit 3 that monitors and controls the functional operations of the transmitting unit and the receiving unit can be connected to the communication network via the transmitting unit, and includes a plurality of shield gasket monitor systems and one monitoring control. A shield gasket monitor system composed of parts can be constructed. In this case, the monitoring control unit has the function of a centralized monitoring control device.

  The present invention can regularly measure the shielding performance of the shield door not only after the installation of the electromagnetic shielding room but also during the operation of the shielding room, so that the shielding room can be operated continuously.

  Also, around the shield door installed at the opening (entrance / exit) of the electromagnetic shielding room, multiple sets of transmitting antennas and receiving antennas face each other in the vertical or horizontal direction of the door, or are combined in the vertical and horizontal directions. The antenna is installed so as to cover the opening, and by sequentially switching to a pair of transmission antennas and reception antennas arbitrarily selected from the plurality of sets of transmission antennas and reception antennas, electromagnetic waves are transmitted and received. The shield performance of each part can be measured with high accuracy.

  In addition, by installing the transmitting antenna inside the electromagnetic shielding room, the receiving antenna outside the electromagnetic shielding room, and further installing the transmitting antenna and the receiving antenna at a short distance, the radio wave propagation loss in the space can be minimized. At the same time, it is possible to reduce the variation in the measured value of the electromagnetic shielding performance by minimizing the adverse effect on the radio wave propagation between the transmitting and receiving antennas.

  The transmission and reception antennas are installed around the shield door at a short distance in the vertical or horizontal direction, but the radio wave propagation range is narrowed, but this is complemented by increasing the number of transmission and reception antennas installed. it can.

  In addition, when measuring the shielding performance of a shield door by radiating radio waves from the transmitting antenna to the receiving antenna, the minimum transmission power that can be recognized by the receiving antenna is used, which affects the surrounding electronic equipment during measurement. Will not affect.

  In the embodiment, since the transmitter and receiver are mounted in the same frame, the transmission / reception part reference signal source (frequency oscillator) is shared, so the system is resistant to frequency fluctuation and easy to handle. It is.

  In addition, since the monitoring control unit (controller) and the transmission / reception unit have a detachable structure and function, the monitoring control unit (controller) can be separated from the system except during initial settings during operation. It is not possible to keep it safe.

  Calibration data taken from the transmission / reception unit to the monitoring control unit (controller) and performance measurement data such as shielding effect values can be independently analyzed by the monitoring control unit (controller).

  FIG. 1 shows a functional block diagram of a multi-antenna control type shield performance measuring apparatus. The monitoring control unit included in the receiving unit 3 that monitors and controls the functional operations of the transmitting unit 1 and the receiving unit 3 in the figure. Can be connected to the communication network via the transmitter 1, and a shield gasket monitor system comprising a plurality of shield gasket monitor systems and one monitor controller can be constructed.

  Further, in this case, the monitoring control unit has the function of a centralized monitoring control device, so that 1 (centralized monitoring control device): N (multiple antenna control type shield gasket monitoring system) can be easily constructed. Furthermore, instead of the monitoring control unit included in the receiving unit 3, a monitoring control unit (controller) 7 may be connected to the communication network.

  FIG. 1 is a functional block diagram of an apparatus for measuring shielding performance of an electromagnetic shielding door (hereinafter referred to as “this apparatus”), and FIG. 2 shows an entrance / exit of an electromagnetic shielding room equipped with this apparatus.

  In the figure, this apparatus is mainly connected between a plurality of transmission antennas TX-1 to TX-n, a transmission unit 1 having a transmitter, and transmission antennas TX-1 to TX-n and the transmission unit 1. Connected between a transmission system comprising a transmission switching unit 2, a plurality of reception antennas RX- 1 to RX-n, a reception unit 3 having a receiver, and reception antennas RX- 1 to RX-n and the reception unit 3. The receiving system is composed of a reception switching unit 4 and a control unit (included in the receiving unit 3) that monitors and controls the functional operations of the transmitting unit 1 and the receiving unit 3. -It is configured as a receiver.

  On the other hand, the shield door 6 is attached to the entrance / exit 5 of the shield room so as to be freely opened and closed, and the shield door 6 is closed around both the outer periphery of the shield door 6 and the inner periphery of the entrance / exit 5 with the shield door 6 closed. A shield gasket (not shown) is attached to prevent electromagnetic waves from leaking out.

  More specifically, each of the plurality of transmitting antennas TX-1 to TX-n and the plurality of receiving antennas RX-1 to RX-n is based on the number of parts for measuring the electromagnetic wave shielding performance or the measurement range of the shield door 6. It is installed around the frame body 5 a of the entrance / exit 5.

  The transmission antennas TX-1 to TX-n are installed inside the shield door 6, the reception antennas RX-1 to RX-n are installed outside the shield door 6, respectively, and the transmission antennas TX-1 to TX are further installed. -N and the receiving antennas RX-1 to RX-n are installed so as to cover the entrance / exit 5 by facing the shield door 6 in the vertical direction or the horizontal direction or by a combination facing the vertical direction and the horizontal direction, respectively. .

  That is, the plurality of transmission antennas TX-1 to TX-n and the reception antennas RX-1 to RX-n are configured to cover the entrance / exit 5 with high-frequency radio waves transmitted and received between the transmission antennas and the reception antennas that are installed facing each other. It is installed in the frame 5 a of the entrance 5.

  In this case, the transmitting antenna and the receiving antenna transmit and receive high-frequency radio waves in a specific combination (facing) such that TX-1 and RX-1, TX-2 and RX-2,. In other cases, for example, TX-1 and RX-2, TX-2 and RX-1,... May be used to transmit and receive high-frequency radio waves in a combination in which other transmitting and receiving antennas cross each other. is there.

  The transmission switching unit 2 is a transmission switching unit for feeding a high-frequency signal output from the transmission unit 1 to a specific transmission antenna among the plurality of transmission antennas TX-1 to TX-n. Switching control is performed from the transmission unit 1.

  The reception switching unit 4 is a reception switching unit for outputting high-frequency radio waves received by a specific antenna among the plurality of reception antennas RX-1 to RX-n to the reception unit 3, and the reception switching unit 4 Switching control is performed from the receiving unit 3.

  This reduces the installation distance (distance) between the transmitting and receiving antennas as much as possible, so that no physical limitation is imposed in the shield room, and transmission power of the transmitter 1 is reduced by reducing radio wave propagation loss in free space. In addition, the effects such as minimizing the adverse effects of radio wave propagation caused by the installation environment of the transmitting and receiving antennas are obtained.

  If the transmission / reception antennas are installed around the shield door 6 at the entrance / exit 5, one set of transmission / reception antennas cannot cover the entire periphery of the shield door 6 at the entrance / exit 5. -Since the receiving antenna is installed, the entire periphery of the shield door 6 can be covered.

  Next, functions and operations of the transmission unit 1, the reception unit 3, and the monitoring control unit (included in the reception unit 3) will be described. The transmission unit 1 includes a PLL synthesized signal generation unit for generating a high-frequency signal, The amplifier is composed of an amplifier, an attenuator and a bandpass filter that increase and decrease the power of the high-frequency signal fed to the transmitting antennas TX-1 to TX-n.

  The reception unit 3 includes a high-sensitivity reception unit including a high-frequency amplification unit that amplifies high-frequency radio waves received by the reception antennas RX-1 to RX-n, a bandpass filter, and a two-stage switching type attenuator, and a PLL synthesized signal. The generator includes a frequency conversion unit using a single conversion method, and an A / D converter that performs analog-digital conversion on the intermediate frequency signal after frequency conversion.

  In addition, there is a monitoring control unit (included in the receiving unit 3) that controls the functional operation of the transmitting unit 1 and the receiving unit 3. The monitoring control unit is composed of a digital signal processor (DSP) and its peripheral circuits. . In particular, the digital signal processor (DSP) includes a switching control of the transmission switching unit (transmission switching unit) 2 in the transmission system, a transmission frequency control of the high frequency signal and a power increase / decrease control of the high frequency signal, and a reception switching unit (reception switching unit) in the reception system. ) 4 switching control, 2-stage switching control of 2-stage switching type attenuator, numerical calculation processing of digital signal output from A / D converter, and frequency information and its signal level information by numerical calculation processing and stored It has a function to hold in the circuit.

  That is, in the transmission system, the required high-frequency signal is transmitted and power is supplied to the transmission antennas TX-1 to TX-n, while in the reception system, the required high-frequency signal is transmitted from the radio waves acquired by the reception antennas RX-1 to RX-n. Extract and perform the functional operation of converting to frequency information and its signal level information.

  Furthermore, the monitoring control unit (included in the receiving unit 3) is connected to a monitoring control unit (controller) 7 described later by a USB cable so that monitoring and control functions can be executed in a dependent manner. Further, depending on the control content designated by the supervisory control unit (controller) 7, even if the supervisory control unit (controller) 7 is not connected, it operates independently.

  Next, functions and operations of the monitoring control unit (controller) 7 will be described.

  A monitoring control unit (controller) 7 using a PC is provided for comprehensively monitoring and controlling the transmission unit 1 and the reception unit 3. In particular, the supervisory control unit (controller) 7 transmits as necessary, such as performance measurement after installation of an electromagnetic shielding room, various settings before normal operation, initial settings such as system calibration, and periodic check and maintenance during operation. Monitoring and control functions can be executed by connecting the unit 1 and the receiving unit 3 with a USB cable. In addition, it has a function (download) for taking in the measurement data stored in the storage circuit of the transmission / reception unit into the monitoring control unit (controller) 7.

  As monitoring and control functions, first, as functions related to the transmission / reception unit, switching control of the transmission switching unit (transmission switching unit) 2 in the transmission system, transmission frequency control of the high frequency signal and power increase / decrease control of the high frequency signal, reception in the reception system Obtained by switching control of the switching unit (reception switching unit) 4, two-stage switching control of the two-stage switching type attenuator, matters relating to numerical calculation processing of the digital signal output from the A / D converter, and numerical calculation processing It has a function to capture frequency information and signal level information.

  In such a configuration, in order to measure the electromagnetic wave shielding performance of the shield door 6, first, the radio wave propagation characteristics (the radio wave propagation loss in space) with the shield door 6 opened are measured, and the receiving antennas RX-1 to RX are measured. The transmission power in the transmission unit (transmitter) 1 for supplying the minimum received power that can be recognized by -n and the reception unit (receiver) 3 is set as a reference value 1. This processing procedure is performed based on the functional flowchart shown in FIG.

  Next, the radio wave propagation characteristics (shield effect) with the shield door 6 closed are observed, and the reception power is minimized so that the reception antennas RX-1 to RX-n and the reception unit (receiver) 3 can recognize the transmission radio waves. The transmission power of the transmitter (transmitter) 1 is increased so that the transmission power at that time is the reference value 2, and the characteristic difference (shielding effect value) between the reference value 1 and the reference value 2 is the shielding performance of the shield door 6. And Here, the measurement and operation of the reference value 1 is called level calibration.

  Note that the transmission power of the transmission unit (transmitter) 1 is the lowest transmission power at which a stable characteristic (reception level) is obtained by the reception unit (receiver) 3. This is to operate the transmission power of the transmitter (transmitter) 1 with as little power as possible so as not to affect the surrounding electronic devices and the like. Details are shown in FIG. 3 to FIG.

  The measurement and setting of the reference value 1 of the transmitter (transmitter) 1 is performed only during installation of this apparatus or during periodic inspections and maintenance, and usually the reference value 2 is measured with the shield door 6 closed. The shield effect value of the shield door 6 is obtained.

  Next, the alarm function will be described. The shield performance value of the shield door 6 is periodically measured, the result is stored in a memory circuit, and the shield performance value is set in a preset range (D / U GREENZONE shown in FIG. 4). When it exceeds D / U YELLOWZONE), it has a function of notifying the operator that the shield performance of the shield door 6 may be deteriorated.

  In addition, the shield performance value of the shield door 6 measured periodically is stored in the storage circuit, and at the same time, the degree of deterioration is set in advance based on the correlation between the stored shield performance values and the mutual difference from the past measurement values. It also has a function to notify the operator that there is a possibility that the shielding performance has deteriorated when the specified range is exceeded.

  Therefore, the operator of the shield room can continuously operate the shield room while satisfying the required shield performance by replacing the deteriorated shield gasket.

  In the figure, “CALIBRASION unit” is “level calibration unit”, “MEASUREMENT unit” is “measurement unit”, and “TRX” is “transmission / reception unit”. “D / U” is “difference between reference value 1 and reference value 2”, “ALM” is “alarm”, “PWR” is power supply, “LED” is “light emitting diode”, and “MEASUREMENT” is “measurement”. , “TX OUT” means “transmission power”, and “TX OUT INCREASE” means “transmission power increase”.

  The present invention can monitor the deterioration status of the shield gasket by periodically measuring the shield performance of the shield door installed at the opening of the shield room not only after the installation of the electromagnetic shield room but also during operation. it can.

It is a block diagram which shows an example of the shield performance measuring apparatus of an electromagnetic wave shield door. It is a cross-sectional view of an electromagnetic shielding door. It is a functional flowchart which shows the whole processing procedure of this apparatus. It is a functional flowchart which shows the detail of D / U measurement of the MEASUREMENT part of FIG. 3 in the process sequence of this apparatus. FIG. 4 is a functional flow diagram showing a CALIBRATION section of FIG. 3 in the processing procedure of this apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission part 2 Transmission switching part 3 Reception part 4 Reception switching part 5 Entrance / exit (opening part)
5a Frame 6 Shield door TX-1 to TX-n Transmitting antenna RX-1 to RX-n Receiving antenna 7 Monitoring controller (controller)

Claims (4)

  Around a shield door installed at the opening of the electromagnetic shielding room, a plurality of sets of transmission antennas and reception antennas, which are located on the indoor side and the outdoor side of the shield door, and are opposed to each other, and the transmission antenna A transmission unit and a reception unit respectively connected to the reception antenna; a transmission switching unit and a reception switching unit connected between the reception antenna and the reception unit; and a transmission switching unit and a reception switching unit respectively connected between the reception antenna and the reception unit; An apparatus for measuring shielding performance of an electromagnetic shielding door, comprising: a control unit that monitors and controls the functional operation of the receiving unit.   The apparatus for measuring shielding performance of an electromagnetic shielding door according to claim 1, wherein the plurality of sets of transmitting antennas and receiving antennas are respectively installed facing the shield door in the vertical direction and / or the lateral direction.   2. The electromagnetic wave shield according to claim 1, wherein the plurality of sets of transmitting antennas and receiving antennas are disposed so as to oppose each other in the vertical direction and / or lateral direction of the shield door, and the opposing directions intersect each other. Door shield performance measuring device.   A shield performance measurement method that measures the shield performance of a shield door installed in the opening of an electromagnetic shield room, and the transmission antenna that propagates around the shield door with the shield door open can be recognized by a receiving antenna. Transmission power for supplying a minimum amount of received power and transmission for supplying a minimum reception power that can be recognized by the reception antenna with a transmission radio wave propagating around the shield door with the shield door closed. A method for measuring the shielding performance of an electromagnetic shielding door, characterized in that a difference from electric power is defined as shielding performance of the shielding door, and an attenuation amount (deterioration) of the shielding performance is measured in a state where the shielding door is closed.

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