Electromagnetic wave testing device and electromagnetic wave testing method

Abstract

To provide an electromagnetic wave testing device with which it is possible to suppress power losses from unexpectedly increasing in radiation immunity test by a hybrid method.SOLUTION: Provided is an electromagnetic wave testing device comprising: a reflection box; a first antenna that is installed in the reflection box and radiates an electromagnetic wave of a frequency lower than the first resonance frequency of the reflection box; a second antenna that is installed in the reflection box and radiates an electromagnetic wave of a frequency higher than or equal to the first resonance frequency; a power feeding device that is connected between a member having ground potential and the first antenna and feeds electricity to the first antenna; a dummy load that is connected between the member having ground potential and the first antenna; a first power loss control unit that has impedance that corresponds to a permissible value regarding power losses by the first antenna when an electromagnetic wave is radiated from the second antenna; and a switching unit that includes a first switching unit that switches the destination for the first antenna between the dummy load and the first power loss control unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electromagnetic wave testing device and an electromagnetic wave testing method. [Background technology]

[0002] Research and development is currently underway on electromagnetic wave testing equipment that uses a reverberation chamber to perform radiated immunity testing. Radiated immunity testing involves applying a uniform, high-intensity electric field to an electronic device placed inside a reverberation chamber as a test piece to verify whether the device operates normally. Note that in this specification, the term "electric field" may be interpreted as either a magnetic field or an electric field.

[0003] A reverberation chamber is composed of a metal cavity resonator, an antenna device that radiates electromagnetic waves into the cavity resonator, and an electromagnetic stirrer that stirs the electromagnetic waves radiated from the antenna device. The reverberation chamber generates an electric field that is applied to a test piece by using the resonance phenomenon of the electromagnetic waves in the cavity resonator. The distribution of the intensity of the electric field thus generated is subject to variations in intensity due to the dimensions of the cavity resonator. In other words, the distribution of the intensity of the electric field generated by the cavity resonator is non-uniform. Therefore, the electromagnetic stirrer stirs the electromagnetic waves in the cavity resonator, making the distribution of the intensity of the electric field generated by the cavity resonator closer to a uniform distribution. This allows users to perform radiated immunity tests with high test quality. For convenience of explanation, this specification will refer to this method of performing radiated immunity tests using the resonance phenomenon in a reverberation chamber as the reverberation chamber method.

[0004] In the resonator chamber method, it is known that the resonant frequency of the cavity resonator is inversely proportional to the size of the cavity resonator. Therefore, in radiated immunity testing using the resonator chamber method, the lower the frequency of the electric field generated in the resonator chamber using the resonance phenomenon, the larger the volume of the resonator chamber must be.

[0005] On the other hand, in radiated immunity testing using an anechoic chamber instead of a reverberation chamber, a low-frequency electric field is applied to electronic devices inside the anechoic chamber. The low-frequency band refers to a frequency band below the lowest usable frequency (LUF) at which the reverberation chamber functions, or below the lowest resonant frequency (i.e., the first resonant frequency) of the reverberation chamber. If a radiated immunity test using such a low-frequency electric field is performed inside a reverberation chamber, the dimensions of the reverberation chamber would be approximately 10 km. A reverberation chamber with such dimensions is undesirable because it limits the flexibility of its installation location. For this reason, in recent years, there has been a demand for reverberation chambers that are equipped with equipment capable of performing radiated immunity testing using low-frequency bands and are large enough to accommodate electrical devices.

[0006] A device known as a transmission line system (TLS) is a device capable of performing radiated immunity testing using low frequency bands in a reverberation chamber. Examples of transmission line systems include devices that apply an electric field to electronic equipment from antennas such as a TEM (Transverse Electro-Magnetic) plate antenna or a stripline. For ease of explanation, this specification will refer to the method of performing radiated immunity testing using a transmission line system as the transmission line system method.

[0007] Here, in a radiated immunity test in which a transmission line system is installed in a reverberation box and the reverberation chamber method and the transmission line system method are combined, it is possible to apply an electric field of a wider frequency band with uniform strength to an electronic device while suppressing an increase in the size of the reverberation box compared to a radiated immunity test using only the reverberation chamber method (see Non-Patent Document 1). For this reason, in recent years, radiated immunity tests have increasingly been performed by installing a transmission line system in a reverberation box and combining the reverberation chamber method and the transmission line system method. In this specification, for convenience of explanation, the method of performing a radiated immunity test by combining the reverberation chamber method and the transmission line system method will be referred to as the hybrid method. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Myron L. Crawford, Mark T. Ma, John M. Ladbury, Bill F. Riddle, "Measurement and Evaluation of a TEM / Reverberating chamber", NIST Technical Note 1342, July, 1990. Summary of the Invention [Problem to be solved by the invention]

[0009] In the hybrid method, when conducting a radiated immunity test using a high frequency band, electromagnetic waves are emitted from an antenna device installed inside a cavity resonator. The high frequency band refers to a frequency band above the lowest frequency that functions as a reverberation chamber, or a frequency band above the lowest resonant frequency (i.e., the first resonant frequency) of the reverberation chamber. In addition, when conducting a radiated immunity test using a low frequency band, the hybrid method stops the electromagnetic wave emission from the antenna device and applies an electric field to the electronic device from a transmission line system installed inside the cavity resonator.

[0010] However, when conducting a radiated immunity test using the hybrid method in a high-frequency band, some of the electromagnetic waves radiated from the antenna device may be received as power by a transmission line system that does not apply an electric field to the electronic device. This is undesirable because it increases power loss in a radiated immunity test using the hybrid method.

[0011] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an electromagnetic wave testing device and an electromagnetic wave testing method that can suppress an increase in power loss in a radiation immunity test using the hybrid method. [Means for solving the problem]

[0012] One aspect of the present invention is an electromagnetic wave testing device comprising: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves at a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves at a frequency equal to or higher than the first resonant frequency; a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna; a dummy load connected between the member having the ground potential and the first antenna; a first power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna; and a switching unit including a first switching unit that switches the connection destination of the first antenna to either the dummy load or the first power loss suppression unit.

[0013] Another aspect of the present invention is an electromagnetic wave testing device including: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves having a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves having a frequency equal to or higher than the first resonant frequency; a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna; a second power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna and different from an open end; and a switching unit including a second switching unit that switches the connection destination of the first antenna to either the power supply device or the second power loss suppression unit.

[0014] and a switching unit including: a first switching unit that switches the connection of the first antenna between the dummy load and the first power loss suppression unit; and a second switching unit that switches the connection of the first antenna between the power loss suppression unit and the second power loss suppression unit, wherein a combined impedance of the impedance of the first power loss suppression unit and the impedance of the second power loss suppression unit is an impedance corresponding to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna.

[0015] and a switching unit including a first switching unit that switches the connection of the first antenna to either the dummy load or the first power loss suppression unit. The first switching unit is configured to switch the connection of the first antenna to either the dummy load or the first power loss suppression unit. The first switching unit is configured to switch the connection of the first antenna to either the dummy load or the first power loss suppression unit. The second ... the first power loss suppression unit. The second switching unit is configured to switch the connection of the first antenna to the first power loss suppression unit. The first switching unit is configured to switch the connection of the first antenna to the dummy load when electromagnetic waves are radiated from the first antenna.

[0016] Another aspect of the present invention is an electromagnetic wave testing method using an electromagnetic wave testing device including: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves at a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves at a frequency equal to or higher than the first resonant frequency; a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna; a second power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna and different from an open end; and a switching unit including a second switching unit that switches the connection of the first antenna to either the power supply device or the second power loss suppression unit, wherein the electromagnetic wave testing method switches the connection of the first antenna to the power supply device when electromagnetic waves are radiated from the first antenna, and switches the connection of the first antenna to the second power loss suppression unit when electromagnetic waves are radiated from the second antenna.

[0017] Another aspect of the present invention is an electromagnetic wave testing method using an electromagnetic wave testing device including: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves at a frequency lower than a first resonance frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves at a frequency equal to or higher than the first resonance frequency; a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna; a dummy load connected between the member having the ground potential and the first antenna; a first power loss suppression unit; a second power loss suppression unit; and a switching unit including a first switching unit that switches a connection destination of the first antenna between the dummy load and the first power loss suppression unit, and a second switching unit that switches a connection destination of the first antenna between the power supply unit and the second power loss suppression unit, a combined impedance of the impedance of the first antenna and the impedance of the second power loss suppression unit is an impedance corresponding to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna, and the electromagnetic wave testing method is such that, when electromagnetic waves are radiated from the first antenna, the first switching unit switches the connection of the first antenna from the first power loss suppression unit to the dummy load, and the second switching unit switches the connection of the first antenna from the second power loss suppression unit to the power supply device, and when electromagnetic waves are radiated from the second antenna, the first switching unit switches the connection of the first antenna from the dummy load to the first power loss suppression unit, and the second switching unit switches the connection of the first antenna from the power supply device to the second power loss suppression unit. [Effects of the Invention]

[0018] According to the present invention, it is possible to suppress an increase in power loss in a radiated immunity test using the hybrid method. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing an example of the configuration of an electromagnetic wave test apparatus 1 according to an embodiment. [Figure 2] 10 is a diagram showing an example of a change in the received power ratio relative to a change in the frequency of an RF signal input to a second antenna 121. FIG. [Figure 3] 10 is a diagram showing an example of a change in the field intensity ratio with respect to a change in the frequency of an RF signal input to a second antenna 121. FIG. [Figure 4] FIG. 10 is a diagram showing an example of a change in the received power ratio when Z is changed. [Figure 5] FIG. 10 is a diagram showing an example of changes in the electric field intensity ratio when Z is changed. [Figure 6] 10 is a diagram showing another example of a change in the field intensity ratio with respect to a change in the frequency of the RF signal input to the second antenna 121. FIG. [Figure 7] FIG. 1 is a diagram showing an example of a flow of a method for performing a radiated immunity test by a hybrid method using an electromagnetic wave test device 1. [Figure 8] 10 is a diagram showing a modified example of the connection between the first antenna 111 and the first power loss suppressing unit 113. FIG. [Figure 9] FIG. 10 is a diagram showing an example of a state of a first antenna 111 connected to a stripline. [Figure 10] 1 is a diagram showing an example of a state of a first antenna 111 connected to a septum. [Figure 11] 1 is a diagram showing an example of a first antenna 111 configured by a plurality of conducting wires, a plurality of flat plates, and the like. DETAILED DESCRIPTION OF THE INVENTION

[0020] <Embodiment> Hereinafter, embodiments of the present invention will be described with reference to the drawings. For simplicity, the following description will be given assuming that there is no or almost no potential difference between multiple components having ground potential. In the following description, the term "electric field" may be read as either a magnetic field or an electromagnetic field. For ease of explanation, the strength of the electric field will be referred to simply as "electric field strength."

[0021] <Configuration of electromagnetic wave test equipment> First, the configuration of an electromagnetic wave test apparatus 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of an electromagnetic wave test apparatus 1 according to an embodiment.

[0022] The electromagnetic wave test device 1 is a device that performs a radiated immunity test on a test subject TM, which is an electronic device that is the target of the radiated immunity test. The radiated immunity test is a test in which a uniform, high-intensity electric field is applied to the test subject TM to check whether the test subject TM operates normally. In the following, as an example, a case will be described in which the test subject TM is an automobile as shown in FIG. 1. Note that the electronic device that is the target of the radiated immunity test as the test subject TM may be any device that is electrically controlled. Therefore, instead of an automobile, the test subject TM may be other electrically controlled devices such as a drive recorder, a multi-function mobile phone terminal (smartphone), a mobile phone terminal, or various types of computers.

[0023] The electromagnetic wave test equipment 1 also performs a radiated immunity test using a hybrid method. The hybrid method is a method of performing a radiated immunity test by combining the reverberation chamber method and the transmission line system (TLS) method. The reverberation chamber method is a method of performing a radiated immunity test using a resonance phenomenon inside a reverberation chamber. The transmission line system method is a method of performing a radiated immunity test using a transmission line system. The transmission line system is a device that applies an electric field to an electronic device from an antenna such as a TEM (Transverse Electro-Magnetic) plate antenna or a stripline.

[0024] The electromagnetic wave testing device 1 includes a reflective box 10, a first testing device 11, a second testing device 12, an electromagnetic stirrer 13, and an information processing device 14.

[0025] The reflective box 10 is a cavity resonator configured as a metal housing capable of accommodating the test specimen TM. In the following, as an example, a case will be described in which the reflective box 10 is a rectangular parallelepiped metal cavity resonator capable of accommodating the test specimen TM therein, as shown in FIG. 1. Note that the shape of the reflective box 10 may be other shapes capable of accommodating the test specimen TM instead of a rectangular parallelepiped shape. However, it is preferable that the shape of the reflective box 10 is a rectangular parallelepiped, as this makes it easier to calculate the resonant frequency of the reflective box 10. In the following, for convenience of explanation, the lowest-order resonant frequency of the reflective box 10 will be referred to as the first resonant frequency.

[0026] The first test device 11 is a transmission line system. That is, in the electromagnetic wave test device 1, the first test device 11 is a device that performs a radiated immunity test on a test piece TM by the transmission line system method.

[0027] The first test device 11 includes a first antenna 111, a dummy load 112, a first power loss suppression unit 113, a first power feeding device 114, a second power loss suppression unit 115, a switching unit 116, and a first control device 117. The switching unit 116 includes a first switching unit SW1 and a second switching unit SW2.

[0028] The first antenna 111 is an antenna that radiates electromagnetic waves with a frequency lower than the first resonant frequency of the reflective chamber 10. The first antenna 111 is an antenna that can be used in a transmission line system. The first antenna 111 is, for example, a TEM plate antenna. Note that the first antenna 111 may be another antenna that can be used in a transmission line system, such as a stripline or a septum, instead of a TEM plate antenna. The TEM plate antenna is a device that applies an electric field to the test piece TM by using the leakage electric field of a parallel plate. The first antenna 111 receives an RF (Radio Frequency) signal from the first power supply device 114 and radiates electromagnetic waves corresponding to the received RF signal. The first antenna 111 is installed on the ceiling of the reflective chamber 10, for example, so as to be located directly above a work area within the reflective chamber 10 where the test piece TM is placed. In this case, the first antenna 111 is installed on the ceiling of the reflective chamber 10 so as to include the entire work area when the reflective chamber 10 is viewed in the direction of gravity. This allows the first antenna 111 to apply an electric field from the ceiling toward the floor to the test piece TM in the work area inside the reflective chamber 10. Note that the first antenna 111 may be configured to be installed at another position where it can apply an electric field to the work area.

[0029] The dummy load 112 is a resistive element connected between the first ground member having a ground potential and the first antenna 111. In the following, as an example, a case will be described in which the impedance of the dummy load 112 is matched to the characteristic impedance of the first antenna 111. Note that the impedance of the dummy load 112 does not have to be matched to the characteristic impedance of the first antenna 111, but it is preferable that the impedance of the dummy load 112 is matched to the characteristic impedance of the first antenna 111 in order to reduce power loss.

[0030] The first power loss suppression unit 113 is a component that suppresses an increase in power loss caused by the first antenna 111 receiving part of the electromagnetic waves radiated from the second antenna 121 when a radiated immunity test using the reflection chamber method is performed by the second test apparatus 12. More specifically, the first power loss suppression unit 113 is a component that has an impedance according to an allowable value for power loss by the first antenna 111 in this case. Details of the first power loss suppression unit 113 will be described later. Note that the power loss by the first antenna 111 in this case may be represented by the power consumed by the first antenna 111 in this case, or may be represented by the amount of reduction in electric field strength inside the reflection chamber 10 due to the first antenna 111 in this case.

[0031] The first power feeding device 114 is a power feeding device that feeds power to the first antenna 111. More specifically, the first power feeding device 114 outputs an RF signal having a frequency lower than the first resonant frequency of the reflection box 10 to the first antenna 111. In the example shown in FIG. 1 , the first power feeding device 114 is controlled by the information processing device 14. In this case, the first power feeding device 114 may have any configuration as long as it is capable of outputting an RF signal of the frequency to the first antenna 111 in response to a request from the information processing device 14. Note that, instead of being controlled by the information processing device 14, the first power feeding device 114 may be provided with an operation unit that accepts operations from a user and be capable of outputting an RF signal of the frequency to the first antenna 111 in response to the operation accepted from the operation unit. The first power feeding device 114 is connected between the first antenna 111 and a second ground member having a ground potential. Note that the second ground member may be the same member as the first ground member or may be a member different from the first ground member.

[0032] The second power loss suppression unit 115 is a component that suppresses an increase in power loss caused by the first antenna 111 receiving part of the electromagnetic waves radiated from the second antenna 121 when a radiation immunity test using a reflection chamber method is performed by the second test apparatus 12. More specifically, the second power loss suppression unit 115 is a component that has an impedance according to the allowable value for power loss by the first antenna 111 in this case. Details of the second power loss suppression unit 115 will be described later. The second power loss suppression unit 115 may be configured integrally with the first power loss suppression unit 113. The following describes, as an example, a case where the second power loss suppression unit 115 is separate from the first power loss suppression unit 113.

[0033] The first switching unit SW1 is a device that switches the connection destination of the first antenna 111 between the dummy load 112 and the first power loss suppression unit 113. The first switching unit SW1 may have any configuration as long as it is capable of switching the connection destination of the first antenna 111 between the dummy load 112 and the first power loss suppression unit 113. In the example shown in FIG. 1 , the first switching unit SW1 is a switching element (e.g., a relay switch, a field effect transistor, etc.) that switches the connection destination of the first antenna 111 between the dummy load 112 and the first power loss suppression unit 113 in response to a request from the first control device 117. Note that the first switching unit SW1 may be configured to include an operation unit that receives an operation to switch the connection destination of the first antenna 111 between the dummy load 112 and the first power loss suppression unit 113, and to switch the connection destination of the first antenna 111 between the dummy load 112 and the first power loss suppression unit 113 in response to the operation received from the operation unit. In this case, the operation unit is, for example, a button, a lever, etc., but is not limited to these.

[0034] The second switching unit SW2 is a device that switches the connection destination of the first antenna 111 between the first power feeding device 114 and the second power loss suppression unit 115. The second switching unit SW2 may have any configuration as long as it is capable of switching the connection destination of the first antenna 111 between the first power feeding device 114 and the second power loss suppression unit 115. In the example shown in FIG. 1 , the second switching unit SW2 is a switching element (for example, a relay switch, a field effect transistor, or the like) that switches the connection destination of the first antenna 111 between the first power feeding device 114 and the second power loss suppression unit 115 in response to a request from the first control device 117. The second switching unit SW2 may be configured to include an operation unit that receives an operation to switch the connection destination of the first antenna 111 between the first power feeding device 114 and the second power loss suppression unit 115, and to switch the connection destination of the first antenna 111 between the first power feeding device 114 and the second power loss suppression unit 115 in accordance with the operation received from the operation unit. In this case, the operation unit is, for example, a button, a lever, or the like, but is not limited to these.

[0035] The first control device 117 is a device that causes the switching unit 116 to switch the connection. More specifically, the first control device 117 controls the first switching unit SW1 to switch the connection destination of the first antenna 111 to either the dummy load 112 or the first power loss suppression unit 113. The first control device 117 also controls the second switching unit SW2 to switch the connection destination of the first antenna 111 to either the first power feeding device 114 or the second power loss suppression unit 115. In the example shown in FIG. 1 , the first control device 117 causes the switching unit 116 to switch the connection in response to a request from the information processing device 14. Note that the first control device 117 may be configured to include an operation unit that receives an operation to cause the switching unit 116 to switch the connection, and to cause the switching unit 116 to switch the connection in response to the operation received from the operation unit.

[0036] The first control device 117 also controls the electromagnetic agitator 13. In the example shown in FIG. 1, the first control device 117 controls the electromagnetic agitator 13 to rotate it. This allows the first control device 117 to cause the electromagnetic agitator 13 to agitate the electromagnetic waves in the reflection box 10. In the example shown in FIG. 1, the first control device 117 controls the electromagnetic agitator 13 in response to a request from the information processing device 14. The first control device 117 may be configured to include an operation unit that receives an operation to control the electromagnetic agitator 13, and to control the electromagnetic agitator 13 in response to the operation received from the operation unit. The first control device 117 may be configured integrally with the information processing device 14.

[0037] The second test device 12 is a device for performing a radiation immunity test on the test piece TM using the reverberation chamber method.

[0038] The second test device 12 includes a second antenna 121 , a second power supply device 122 , and a second control device 123 .

[0039] The second antenna 121 is an antenna that radiates electromagnetic waves having a frequency equal to or higher than the first resonant frequency of the reflective box 10. The second antenna 121 may have any configuration as long as it is an antenna that can radiate the electromagnetic waves. The second antenna 121 acquires an RF signal from the second power feeding device 122 and radiates electromagnetic waves according to the acquired RF signal. The second antenna 121 is installed inside the reflective box 10. The position at which the second antenna 121 is installed inside the reflective box 10 may be any position within the area of ​​the reflective box 10 that is outside the aforementioned working area. The second antenna 121 acquires an RF signal from the second power feeding device 122 and radiates electromagnetic waves according to the acquired RF signal.

[0040] The second power supply device 122 is a power supply device that supplies power to the second antenna 121. More specifically, the second power supply device 122 outputs an RF signal having a frequency equal to or higher than the first resonant frequency of the reflection box 10 to the second antenna 121. In the example shown in FIG. 1 , the second power supply device 122 is controlled by the information processing device 14. In this case, the second power supply device 122 may have any configuration as long as it is capable of outputting an RF signal of the frequency to the second antenna 121 in response to a request from the information processing device 14. Note that instead of being controlled by the information processing device 14, the second power supply device 122 may be provided with an operation unit that accepts operations from a user and is capable of outputting an RF signal of the frequency to the second antenna 121 in response to the operation accepted from the operation unit. The second power supply device 122 is connected between the second antenna 121 and a third ground member having a ground potential. Note that the third ground member may be the same member as the first ground member or may be a member different from the first ground member. Furthermore, the third ground member may be the same member as the second ground member, or may be a different member from the second ground member.

[0041] The second control device 123 is a control device that controls the electromagnetic agitator 13. In the example shown in FIG. 1, the second control device 123 controls the electromagnetic agitator 13 to rotate it. This allows the second control device 123 to cause the electromagnetic agitator 13 to agitate the electromagnetic waves in the reflection chamber 10. In the example shown in FIG. 1, the second control device 123 controls the electromagnetic agitator 13 in response to a request from the information processing device 14. Note that the second control device 123 may be configured to include an operation unit that receives an operation to control the electromagnetic agitator 13, and to control the electromagnetic agitator 13 in response to the operation received from the operation unit. Furthermore, the second control device 123 may be configured integrally with either or both of the first control device 117 and the information processing device 14.

[0042] The electromagnetic stirrer 13 is installed in the reflective chamber 10 and stirs the electromagnetic waves within the reflective chamber 10. This allows the reflective chamber 10 to reduce variations in the electric field intensity within the working area. The electromagnetic stirrer 13 may have any configuration as long as it can stir the electromagnetic waves within the reflective chamber 10. In the example shown in FIG. 1 , the electromagnetic stirrer 13 includes a shaft, four flat, rectangular stirring blades aligned along the shaft, and a drive unit that rotates the shaft. In this case, the electromagnetic stirrer 13 is controlled by the first control device 117 and the second control device 123, respectively, and stirs the electromagnetic waves within the reflective chamber 10 with the four stirring blades that rotate together with the shaft. Therefore, the first control device 117 and the second control device 123 each control the drive unit to rotate the shaft. The electromagnetic stirrer 13 may be configured to be included in the first testing device 11 or the second testing device 12.

[0043] The information processing device 14 controls the first power supply device 114, the first control device 117, the second power supply device 122, and the second control device 123 in response to an operation received from a user. The information processing device 14 is, for example, an information processing device such as a notebook PC (Personal Computer), a desktop PC, a workstation, a tablet PC, a multi-function mobile phone terminal, a mobile phone terminal, or a PDA (Personal Digital Assistant), but is not limited to these.

[0044] The information processing device 14 is connected by wire or wirelessly to each of the first power supply device 114, the first control device 117, the second power supply device 122, and the second control device 123 so as to be able to communicate with them. However, due to the nature of the radiation immunity test, it is preferable that the information processing device 14 is connected by wire to each of the first power supply device 114, the first control device 117, the second power supply device 122, and the second control device 123 so as to be able to communicate with them.

[0045] <Power loss caused by the first antenna in the reverberation chamber method> The power loss caused by the first antenna 111 in the reflector chamber method will be described below.

[0046] In the reverberation chamber method, the electromagnetic wave test apparatus 1 radiates electromagnetic waves of a first resonance frequency or higher from the second antenna 121. As a result, the electromagnetic wave test apparatus 1 generates an electric field that is applied to the test piece TM due to the resonance phenomenon of the electromagnetic waves in the reverberation chamber 10. At this time, the first antenna 111 receives the electromagnetic waves in the reverberation chamber 10.

[0047] When the electromagnetic waves in the reflection box 10 are received by the first antenna 111 and the first antenna 111 is connected to at least one of the first power supply device 114 and the dummy load 112, the first antenna 111 will pass a current through the connected component to a component having a ground potential. Therefore, in the electromagnetic wave test device 1, when a radiation immunity test using the reflection box method is performed, the power loss caused by the first antenna 111 can be expressed by a received power ratio. The received power ratio is the ratio between the power input to the second antenna 121 as an RF signal and the power received by the first antenna 111 (i.e., the power consumed by the first antenna 111).

[0048] FIG. 2 illustrates an example of the change in the received power ratio with respect to the change in the frequency of the RF signal input to the second antenna 121. Note that FIG. 2 shows an example of the results of measuring the received power ratio while changing the frequency when only the dummy load 112 is connected to the first antenna 111 and electromagnetic waves are radiated from the second antenna 121. The vertical axis of the graph shown in FIG. 2 represents the received power ratio. The horizontal axis of the graph represents the frequency of the RF signal input to the second antenna 121. In the example shown in FIG. 2, the frequency average of the received power ratio is 0.16. That is, FIG. 2 indicates that in the electromagnetic wave test apparatus 1 when only the dummy load 112 is connected to the first antenna 111, 16% of the power input to the second antenna 121 as an RF signal is lost. Although not shown, it has also been measured that the frequency average of the received power ratio is approximately 0.16 in the electromagnetic wave test apparatus 1 when only the first power supply device 114 is connected to the first antenna 111. In the electromagnetic wave test apparatus 1, when both the dummy load 112 and the first power supply device 114 are connected to the first antenna 111, the frequency average of the received power ratio is measured to be about 0.32. Intuitively, this is thought to be a result of the path through which current flows from the first antenna 111 being doubled. Therefore, in this case, it is known that the electromagnetic wave test apparatus 1 loses about 32% of the power input to the second antenna 121 as an RF signal.

[0049] On the other hand, when the electromagnetic waves in the reflection box 10 are received by the first antenna 111, the first antenna 111 reduces the electric field strength in the reflection box 10. Therefore, in the electromagnetic wave test apparatus 1, when a radiation immunity test using the reflection box method is performed, the power loss due to the first antenna 111 can also be expressed by an electric field strength ratio. The electric field strength ratio is the ratio of the electric field strength in the reflection box 10 when electromagnetic waves are radiated from the second antenna 121 in the reflection box 10 with the first antenna installed to the electric field strength in the reflection box 10 when electromagnetic waves are radiated from the second antenna 121 in the reflection box 10 with the first antenna not installed. The first antenna not installed state refers to a state of the reflection box 10 where the first antenna 111 is not installed. The first antenna installed state refers to a state of the reflection box 10 where the first antenna 111 is installed and the dummy load 112 and the first power supply device 114 are installed to the first antenna 111.

[0050] FIG. 3 is a diagram showing an example of a change in the field strength ratio with respect to a change in the frequency of the RF signal input to the second antenna 121. In FIG. 3, the field strength ratio is represented by a deviation. The vertical axis of the graph shown in FIG. 3 represents the field strength ratio represented by the deviation. The horizontal axis of the graph represents the frequency of the RF signal input to the second antenna 121. In the example shown in FIG. 3, the frequency average of the field strength ratio is −2.1 dB. This indicates that the field strength in the reflector box 10 when the second antenna 121 radiates electromagnetic waves in the reflector box 10 with the first antenna installed is approximately 20% lower than the field strength in the reflector box 10 when the second antenna 121 radiates electromagnetic waves in the reflector box 10 without the first antenna installed. In other words, this means that in the electromagnetic wave testing device 1 when both the dummy load 112 and the first power supply device 114 are connected to the first antenna 111, 20% of the electric field generated in the reflection chamber 10 by the radiation of electromagnetic waves from the second antenna 121 is lost as power by the first antenna 111.

[0051] As described above, the power loss due to the first antenna 111 when performing a radiation immunity test using the reverberation chamber method can be expressed by the received power ratio and the field intensity ratio. The cause of this power loss is that the first antenna 111 passes current to a component having a ground potential via the dummy load 112 and the first power feeding device 114. Therefore, in this case, the electromagnetic wave test apparatus 1 controls the switching unit 116 to switch the connection destination of the first antenna 111 from the dummy load 112 and the first power feeding device 114 to the first power loss suppression unit 113 and the second power loss suppression unit 115. This allows the electromagnetic wave test apparatus 1 to suppress an increase in power loss due to the first antenna 111 in a radiation immunity test using the reverberation chamber method, which is one of the radiation immunity tests using the hybrid method. That is, the electromagnetic wave test apparatus 1 can suppress an increase in power loss due to the first antenna 111 in a radiation immunity test using the hybrid method. This is because the first power loss suppression unit 113 and the second power loss suppression unit 115 each suppress an increase in power loss due to the first antenna 111. Therefore, hereinafter, the reason why the first power loss suppression unit 113 and the second power loss suppression unit 115 each suppress an increase in power loss due to the first antenna 111 will be described.

[0052] <Reason for reducing power loss due to the first antenna> The reason why the first power loss suppression unit 113 and the second power loss suppression unit 115 each suppress an increase in power loss caused by the first antenna 111 will be described below. To explain this reason, a case will be described below in which the dummy load 112, the first power feeding device 114, the first power loss suppression unit 113, and the second power loss suppression unit 115 are not connected to the first antenna 111, and a resistive element X having an impedance represented by a variable Z is connected between the first antenna 111 and a member having ground potential. In this case, the above-mentioned received power ratio and field intensity ratio change depending on the value of Z. Furthermore, a case in which the characteristic impedance Z0 of the first antenna 111 is 50 [Ω] will be described below as an example.

[0053] FIG. 4 is a diagram showing an example of how the received power ratio changes when Z is changed. In FIG. 4, the received power ratio is expressed as a percentage. The vertical axis of the graph shown in FIG. 4 represents the received power ratio expressed as a percentage. The horizontal axis of the graph represents the value of Z. The curve plotted on the graph is a curve for the received power ratio calculated by theoretical calculation. In the example shown in FIG. 4, the received power ratio is maximized when Z is 50 [Ω]. This is because, in this example, when Z is 50 [Ω], the characteristic impedance of the first antenna 111 and the impedance of the resistive element X match. In this case, the received power ratio decreases as Z becomes smaller than 50 [Ω] and decreases as Z becomes larger than 50 [Ω]. Here, by obtaining this graph through prior experiments or the like, the manufacturer of the electromagnetic wave test apparatus 1 can determine the value of Z so that the received power ratio is equal to or smaller than a predetermined first allowable value. For example, if the graph is considered to have been obtained through prior experiments or the like and the first tolerance is set to 10% then the manufacturer can determine the value of Z to be a value equal to or less than X1 or equal to or greater than X2 based on the graph. X1 is the smaller of the two Z values ​​at which the received power ratio is 10% on the graph, and is 4Ω. X2 is the larger of the two Z values ​​at which the received power ratio is 10% on the graph, and is 615Ω.

[0054] Therefore, when the first power loss suppression unit 113 and the second power loss suppression unit 115 are connected to the first antenna 111 instead of the resistive element X, and the combined impedance of the impedance of the first power loss suppression unit 113 and the impedance of the second power loss suppression unit 115 is a first impedance I11 that is less than or equal to X1, the electromagnetic wave test apparatus 1 can suppress the received power ratio to less than or equal to the first allowable value when performing a radiated immunity test using the reverberation chamber method. Also, when the first power loss suppression unit 113 and the second power loss suppression unit 115 are connected to the first antenna 111 instead of the resistive element X, and the combined impedance is a second impedance I12 that is greater than or equal to X2, the electromagnetic wave test apparatus 1 can suppress the received power ratio to less than or equal to the first allowable value when performing a radiated immunity test using the reverberation chamber method. That is, the electromagnetic wave test apparatus 1 can suppress an increase in power loss in a radiated immunity test using the hybrid method.

[0055] In addition, when the first power loss suppression unit 113 is connected to the first antenna 111 instead of the resistive element X (i.e., when the first power loss suppression unit 113 is connected to the first antenna 111 and the second power loss suppression unit 115 is not connected to the first antenna 111), the impedance of the first power loss suppression unit 113 is set to the first impedance I11 or the second impedance I12, so that the electromagnetic wave testing apparatus 1 can suppress the received power ratio in the radiated immunity test using the reverberation chamber method to be equal to or less than the first permissible value. Furthermore, when the second power loss suppression unit 115 is connected to the first antenna 111 instead of the resistive element X (i.e., when the second power loss suppression unit 115 is connected to the first antenna 111 and the first power loss suppression unit 113 is not connected to the first antenna 111), the impedance of the second power loss suppression unit 115 is set to the first impedance I11 or the second impedance I12, so that the electromagnetic wave test apparatus 1 can suppress the received power ratio in a radiated immunity test using the reflection chamber method to a first allowable value or less. Therefore, even when either the first power loss suppression unit 113 or the second power loss suppression unit 115 is connected to the first antenna 111 instead of the resistive element X, the electromagnetic wave test apparatus 1 can suppress the power loss represented by the received power ratio as the power loss due to the first antenna 111 to a first allowable value or less.

[0056] FIG. 5 shows an example of how the field intensity ratio changes when Z is changed. In FIG. 5, the field intensity ratio is expressed as a percentage. The vertical axis of the graph shown in FIG. 5 represents the field intensity ratio expressed as a percentage. The horizontal axis of the graph represents the value of Z. The curve plotted on the graph represents the field intensity ratio calculated by theoretical calculation. In the example shown in FIG. 5, the field intensity ratio is minimum when Z is 50 Ω. This is because, as described above, in this example, when Z is 50 Ω, the characteristic impedance of the first antenna 111 and the impedance of the resistive element X match. In this case, the field intensity ratio increases as Z decreases below 50 Ω and increases as Z increases above 50 Ω. By obtaining this graph through prior experiments or the like, the manufacturer of the electromagnetic wave test apparatus 1 can determine the value of Z so that the field intensity ratio is equal to or greater than a predetermined second allowable value. For example, if the graph is considered to be a graph obtained through prior experiments or the like and the second tolerance is set to 90[%], the manufacturer can determine the value of Z to be a value equal to or less than X3 or a value equal to or greater than X4. In the example shown in FIG. 5, X3 is the smaller of the two Z values ​​that result in a field strength ratio of 90[%], which is 9[Ω]. Also, in the example shown in FIG. 5, X4 is the larger of the two Z values ​​that result in a field strength ratio of 90[%], which is 255[Ω].

[0057] Therefore, when the first power loss suppression unit 113 and the second power loss suppression unit 115 are connected to the first antenna 111 instead of the resistive element X, and when the combined impedance of the impedance of the first power loss suppression unit 113 and the impedance of the second power loss suppression unit 115 is a first impedance I21 that is less than or equal to X3, the electromagnetic wave test apparatus 1 can suppress the power loss represented by the field intensity ratio, as the power loss due to the first antenna 111, to equal to or greater than the second allowable value when performing a radiated immunity test using the reverberation chamber method. Also, when the first power loss suppression unit 113 and the second power loss suppression unit 115 are connected to the first antenna 111 instead of the resistive element X, and when the combined impedance is a second impedance I22 that is greater than or equal to X4, the electromagnetic wave test apparatus 1 can suppress the power loss represented by the field intensity ratio, as the power loss due to the first antenna 111, to equal to or greater than the second allowable value when performing a radiated immunity test using the reverberation chamber method. That is, the electromagnetic wave test apparatus 1 can prevent an increase in power loss in a radiation immunity test using the hybrid method.

[0058] In addition, when the first power loss suppression unit 113 is connected to the first antenna 111 instead of the resistive element X (i.e., when the first power loss suppression unit 113 is connected to the first antenna 111 and the second power loss suppression unit 115 is not connected to the first antenna 111), the impedance of the first power loss suppression unit 113 is set to the first impedance I21 or the second impedance I22, so that the electromagnetic wave testing apparatus 1 can suppress the field intensity ratio in the radiated immunity test using the reverberation chamber method to be equal to or greater than the second permissible value. Furthermore, when the second power loss suppression unit 115 is connected to the first antenna 111 instead of the resistive element X (i.e., when the second power loss suppression unit 115 is connected to the first antenna 111 and the first power loss suppression unit 113 is not connected to the first antenna 111), the impedance of the second power loss suppression unit 115 is set to the first impedance I21 or the second impedance I22, so that the electromagnetic wave testing apparatus 1 can suppress the field intensity ratio in the radiated immunity test using the reverberation chamber method to a value equal to or greater than the second allowable value. Therefore, even when either the first power loss suppression unit 113 or the second power loss suppression unit 115 is connected to the first antenna 111, the electromagnetic wave testing apparatus 1 can suppress the power loss represented by the field intensity ratio as the power loss due to the first antenna 111 to a value equal to or greater than the second allowable value.

[0059] Here, when the combined impedance of the impedance of first power loss suppression unit 113 and the impedance of second power loss suppression unit 115 is first impedance I11 or first impedance I21, each of first power loss suppression unit 113 and second power loss suppression unit 115 may be a resistive element having an impedance such that the combined impedance becomes first impedance I11 or first impedance I21, or may be another circuit element having an impedance such that the combined impedance becomes first impedance I11 or first impedance I21, or may be a fourth ground member having a ground potential. The fourth ground member may be the same member as some or all of the first to third ground members, or may be a member different from all of the first to third ground members. Furthermore, when the composite impedance is the second impedance I12 or the second impedance I22, each of the first power loss suppression unit 113 and the second power loss suppression unit 115 may be a resistive element having an impedance such that the composite impedance becomes the second impedance I12 or the second impedance I22, or may be another circuit element having an impedance such that the composite impedance becomes the second impedance I12 or the second impedance I22, or may be an open end. With this configuration, the first power loss suppression unit 113 and the second power loss suppression unit 115 can suppress an increase in power loss by the first antenna 111.

[0060] Furthermore, when the impedance of first power loss suppression unit 113 is set to first impedance I11 or first impedance I21, first power loss suppression unit 113 may be a resistive element having the first impedance I11 or first impedance I21, another circuit element having an impedance such that the combined impedance is the first impedance I11 or first impedance I21, or a fourth ground member having a ground potential. The fourth ground member may be the same member as some or all of the first to third ground members, or may be a member different from all of the first to third ground members. Furthermore, when the impedance of first power loss suppression unit 113 is set to second impedance I12 or second impedance I22, first power loss suppression unit 113 may be a resistive element having the second impedance I12 or second impedance I22, another circuit element having an impedance such that the combined impedance is the second impedance I12 or second impedance I22, or an open end. With this configuration, the first power loss suppressing unit 113 can suppress an increase in power loss caused by the first antenna 111.

[0061] Furthermore, when the impedance of second power loss suppression unit 115 is set to the first impedance I11 or the first impedance I21, second power loss suppression unit 115 may be a resistive element having the first impedance I11 or the first impedance I21, another circuit element having an impedance such that the combined impedance is the first impedance I11 or the first impedance I21, or a fifth ground member having a ground potential. The fifth ground member may be the same member as some or all of the first to fourth ground members, or may be a member different from all of the first to fourth ground members. Furthermore, when the impedance of second power loss suppression unit 115 is set to the second impedance I12 or the second impedance I22, second power loss suppression unit 115 may be a resistive element having the second impedance I12 or the second impedance I22, another circuit element having an impedance such that the combined impedance is the second impedance I12 or the second impedance I22, or an open end. With this configuration, the second power loss suppressing unit 115 can suppress an increase in power loss caused by the first antenna 111.

[0062] As described above, by including the first power loss suppression unit 113 and the second power loss suppression unit 115 instead of the resistive element X and the switching unit 116, the electromagnetic wave test apparatus 1 can suppress an increase in power loss in a radiated immunity test using the hybrid method. The method for determining the first impedance I11, the second impedance I12, the first impedance I21, and the second impedance I22 described above requires obtaining the graphs shown in FIGS. 4 and 5 through prior experiments or the like, and is not a method that can be used in the design stage. Therefore, a method using theoretical formulas can be adopted as a method for determining X3 and X4 among the above-mentioned X1 to X4. This method is more versatile and useful than the on-site fitting method, because it allows X3 to be specified as the first threshold value for Z (i.e., the first threshold value for the first impedance I21) and X4 to be specified as the second threshold value for Z (i.e., the second threshold value for the second impedance I22) from the design stage. In addition, in the method of determining the first threshold value and the second threshold value using this theoretical formula, a condition that must be satisfied by the composite impedance of the impedance of the first power loss suppression unit 113 and the impedance of the second power loss suppression unit 115 is obtained as the impedance for suppressing the power loss represented by the field intensity ratio as the power loss by the first antenna 111 to a second allowable value or more. For ease of explanation, the composite impedance of the impedance of the first power loss suppression unit 113 and the impedance of the second power loss suppression unit 115 will be simply referred to as the composite impedance below.

[0063] <Method of determining the first and second thresholds from a theoretical formula> A method for determining the first and second thresholds from a theoretical formula will be described below. For the sake of convenience, the following description will be given: the dummy load 112, the first power supply device 114, the first power loss suppression unit 113, and the second power loss suppression unit 115 are not connected to the first antenna 111; and only a resistive element X having an impedance represented by a variable Z is connected to the first antenna 111. The following description will also be given assuming that the resistive element X is further connected to a member having a ground potential. Also, as an example, the following description will be given assuming that the characteristic impedance Z0 of the first antenna 111 is 50 Ω. For ease of explanation, the normalized impedance obtained by normalizing Z by Z0 will be denoted by Z'.

[0064] First, according to electromagnetism, the reflection coefficient Γ due to the mismatch between the characteristic impedance of the first antenna 111 and the impedance of the resistive element X is expressed as the following equation (1) using Z′.

[0065]

number

[0066] Therefore, the transmission power coefficient S for the power transmitted from the first antenna 111 to the resistive element X is expressed as the following equation (2) using the reflection coefficient Γ.

[0067]

number

[0068] And the power consumption ratio r loss is the received power ratio r when Γ=0 (i.e., when the power loss by the first antenna 111 is maximum). p and the transmitted power coefficient S, it is expressed as the following equation (3).

[0069]

number

[0070] However, when there are two paths through which current flows from the first antenna 111 (that is, when the first antenna 111 is connected to both the first antenna 111 and the first power supply device 114), as described above, the received power ratio r p Therefore, in this case, the power consumption ratio r loss Therefore, the effective power ratio r Pnet is expressed as the following equation (4).

[0071]

number

[0072] In the reflection box method, the reflection box 10 generates an electric field of uniform strength inside the reflection box 10 due to a resonance phenomenon. If it is assumed that an electric field of uniform strength is applied to each of the wall surface of the reflection box 10 and the first antenna 111, then based on the concept of the effective area of ​​the antenna, it can be considered that the power received by the wall surface of the reflection box 10 is proportional to the surface area of ​​the wall surface, and the power received by the first antenna 111 is proportional to the surface area of ​​the first antenna 111. As a result, the above equation (4) can be expressed as follows: S_ref and the second area ratio r S Based on this, the first area ratio r can be rewritten as follows to be scalable as in equation (5). S_ref is the ratio of the surface area of ​​the first antenna 111 to the surface area of ​​a reflector box having a reference received power ratio. The second area ratio is the ratio of the surface area of ​​the first antenna 111 to the surface area of ​​a reflector box for which the first and second thresholds are determined. As a result, the effective power ratio r Pnet the first area ratio r S_ref and the second area ratio r SIt can be obtained by scaling based on the above. In this embodiment, the surface area of ​​a certain reflecting box refers to the inner surface area of ​​the reflecting box. In this embodiment, the surface area of ​​the first antenna 111 refers to the area of ​​the largest plane that covers the radiating element of the first antenna 111.

[0073]

number

[0074] The effective power ratio r expressed by the above equation (5) Pnet The square root of the electric field strength ratio r E Represents.

[0075]

number

[0076] From the above equations (1) to (6) derived in this way, the electric field strength ratio r E can be related to Z. Specifically, by substituting the above formula (5) into formula (6), the following formula (7) is obtained.

[0077]

number

[0078] Moreover, by substituting the above formula (7) into formula (3), the following formula (8) is obtained.

[0079]

number

[0080] Furthermore, by substituting the above equation (8) into equation (2) and then solving for Γ, the following equation (9) is obtained.

[0081]

number

[0082] Then, by substituting the above equation (9) into equation (1) and then solving for Z', the following equation (10) is obtained.

[0083]

number

[0084] Here, the above equation (10) can be transformed into the following equations (11) and (12) for Z by multiplying both sides of equation (10) by Z0. In this way, the electric field strength ratio r E can be related to Z. In equation (11), "=" is rewritten as "≧" to treat Z in equation (11) as the first threshold value mentioned above. Also, in equation (12), "=" is rewritten as "≦" to treat Z in equation (12) as the second threshold value mentioned above.

[0085]

number

[0086]

number

[0087] The above formulas (11) and (12) are used to calculate the desired field strength ratio r E is an equation showing the condition that Z must satisfy when it is desired to obtain the impedance I21. For the sake of convenience, the condition shown by equation (11) will be referred to as the first condition below. The maximum value of Z that satisfies the first condition is the first threshold value described above. In other words, Z that satisfies the first condition is the first impedance I21 described above. More specifically, the first condition is the ratio r of the second allowable value and the surface area of ​​the first antenna 111 to the surface area of ​​the reflector box 10. Sand the characteristic impedance Z0 of the first antenna 111. For ease of explanation, the condition indicated by equation (12) will be referred to as the second condition in the following description. The minimum value of Z that satisfies the second condition is the second threshold value described above. That is, Z that satisfies the second condition is the second impedance I22 described above. More specifically, the second condition is also determined by the second allowable value and the ratio r of the surface area of ​​the first antenna 111 to the surface area of ​​the reflector box 10. S and the characteristic impedance Z0 of the first antenna 111.

[0088] In the method of determining the first threshold and the second threshold from theoretical formulas, the first threshold is determined using formula (11) derived in this way, and the second threshold is determined using formula (12). These two thresholds can be used as thresholds for the impedances of the first power loss suppression unit 113 and the second power loss suppression unit 115, because the derivation of formula (4) above already takes into account that there are two paths through which current flows from the first antenna 111.

[0089] Here, for example, the frequency average of the received power ratio shown in Figure 2 is 0.16, S_ref =0.039, equations (11) and (12) become the following equations (13) and (14).

[0090]

number

[0091]

number

[0092] Then, the desired field strength ratio r E When is 90[%], the formulas (13) and (14) become the following formulas (15) and (16).

[0093]

number

[0094]

number

[0095] The decrease in the electric field strength inside the reflector box 10 affects the power capacity of the second power supply device 122. Therefore, it is desirable that the decrease in the electric field strength inside the reflector box 10 is 10% or less, taking into account the output error of the second power supply device 122. The decrease in the electric field strength inside the reflector box 10 being 10% or less means that the second tolerance is 90% or more. That is, in the above example, the desired electric field strength ratio r E Setting the value to 90% is appropriate from the perspective of actual design. However, the desired field strength ratio r E may be a value smaller than 90[%] or may be a value larger than 90[%].

[0096] In addition, the second area ratio r S As described above, the second area ratio r is the ratio of the surface area of ​​the first antenna 111 to the surface area of ​​the reflector box for which the first and second thresholds are determined. S For example, the surface area of ​​the first antenna 111 relative to the surface area of ​​the reflector box 10 is substituted into r. Furthermore, the reflector box having the reference received power ratio may be any reflector box as long as the received power ratio has been measured. Therefore, the first area ratio r S_ref may be the surface area of ​​the first antenna 111 relative to the surface area of ​​the reflective box 10.

[0097] As described above, the manufacturer of the electromagnetic wave test apparatus 1 can determine the first and second thresholds at the design stage based on any combination of Equations (11) and (12), Equations (13) and (14), or Equations (15) and (16). As a result, the manufacturer can determine the impedances of the first power loss suppression unit 113 and the second power loss suppression unit 115 so that either the first impedance I21, which is equal to or less than the first threshold, or the second impedance I22, which is equal to or greater than the second threshold, becomes the combined impedance. The electromagnetic wave test apparatus 1, which includes the first power loss suppression unit 113 and the second power loss suppression unit 115 having the impedances determined in this manner, can suppress an increase in power loss in a radiated immunity test using the hybrid method.

[0098] Here, when first power loss suppression unit 113 and second power loss suppression unit 115 are connected to first antenna 111 and then electromagnetic waves are radiated from second antenna 121 while changing the frequency of the RF signal input to second antenna 121, the field intensity ratio changes as shown in FIG. 6. FIG. 6 is a diagram showing another example of the change in field intensity ratio with respect to the change in frequency of the RF signal input to second antenna 121. However, in FIG. 6, the field intensity ratio is expressed by deviation. The vertical axis of the graph shown in FIG. 6 represents the field intensity ratio expressed by deviation. Furthermore, the horizontal axis of the graph represents the frequency of the RF signal input to second antenna 121. In the example shown in FIG. 6, the frequency average of the field intensity ratio is −0.3 dB. 6 clearly shows that when the switching unit 116 connects each of the first power loss suppression unit 113 and the second power loss suppression unit 115 to the first antenna 111, the field intensity ratio represented by the deviation decreases compared to when the dummy load 112 and the first power feeding device 114 are connected to the first antenna 111. Therefore, the electromagnetic wave test apparatus 1 can suppress an increase in power loss in a radiation immunity test using the hybrid method.

[0099] <Method of conducting radiated immunity testing using the hybrid method using electromagnetic wave testing equipment> A method for performing a radiated immunity test by the hybrid method using the electromagnetic wave testing apparatus 1 will be described below with reference to Fig. 7. Fig. 7 is a diagram showing an example of the flow of a method for performing a radiated immunity test by the hybrid method using the electromagnetic wave testing apparatus 1. For ease of explanation, the person performing the radiated immunity test by the hybrid method using the electromagnetic wave testing apparatus 1 will be referred to as the measurer in the following description.

[0100] The measurer operates the information processing device 14 and inputs various pieces of information into the information processing device 14 (step S110). In Fig. 7, the procedure of step S110 is indicated by "information input." Here, the various pieces of information include information indicating measurement conditions such as the frequency band of the RF signal input to the first antenna 111, the frequency band of the RF signal input to the second antenna 121, and the rotation speed of the electromagnetic stirrer 13. Note that the various pieces of information may also include other information.

[0101] Next, the measurer operates the information processing device 14 to start a first radiation immunity test (step S120). Here, the first radiation immunity test refers to a radiation immunity test using a transmission line system method. Also, in step S120, the measurer switches the connection of the first antenna 111 using the switching unit 116 so that the first antenna 111 is connected to the dummy load 112 and the first power supply device 114 after the rotation speed input to the information processing device 14 in step S110 matches the rotation speed of the electromagnetic stirrer 13, at a timing before the first antenna 111 emits electromagnetic waves. Thereafter, the measurer operates the information processing device 14 to start inputting an RF signal of the frequency band input to the information processing device 14 in step S110 to the first antenna 111.

[0102] Next, the operator begins monitoring for defects occurring in the specimen TM (step S130). Defects occurring in the specimen TM include, but are not limited to, image distortion on the display in the case of the specimen TM having a display, or a stoppage of power supply from the power source to the specimen TM.

[0103] Next, the measurer determines whether or not a defect has occurred in the specimen TM (step S140).

[0104] If the measurer determines that no defect has occurred in the specimen TM (step S140-NO), the process proceeds to step S150.

[0105] On the other hand, if the measurer determines that a defect has occurred in the specimen TM (step S140-YES), the measurer records information indicating the defect that has occurred in the specimen TM (step S220). Note that the method for recording the information in step S220 may be any method that can record the information. After the processing of step S220 is performed, the measurer proceeds to step S150.

[0106] In step S150, the measurer determines whether or not to end the first radiated immunity test started in step S120 (step S150). In FIG. 7, the procedure of step S170 is indicated by "Test End?". Here, for example, if the first radiated immunity test started in step S120 has been completed, the measurer determines to end the first radiated immunity test started in step S120. On the other hand, for example, if the first radiated immunity test started in step S120 has not been completed, the measurer determines not to end the first radiated immunity test started in step S120. Note that the determination in step S150 may be made by other methods.

[0107] If the measurer determines not to end the first radiated immunity test started in step S120 (step S150-NO), the process proceeds to step S140, where the measurer determines again whether or not a defect has occurred in the test piece TM.

[0108] On the other hand, if the measurer determines to end the first radiation immunity test started in step S120 (step S150-YES), the measurer ends the first radiation immunity test (step S160). Here, in step S160, the measurer operates, for example, the information processing device 14 to end the input of the RF signal to the first antenna 111.

[0109] Next, the measurer starts a second radiation immunity test (step S170). Here, the second radiation immunity test is a radiation immunity test using a reverberation chamber method. Also, in step S170, the measurer causes switching unit 116 to switch the connection of first antenna 111 so that first antenna 111 is connected to both first power loss suppression unit 113 and second power loss suppression unit 115, at a timing before second antenna 121 is caused to emit electromagnetic waves. Thereafter, the measurer operates information processing device 14 to start inputting, to second antenna 121, an RF signal of the frequency band input to information processing device 14 in step S110.

[0110] Next, the measurer starts monitoring for defects occurring in the specimen TM (step S180).

[0111] Next, the measurer determines whether or not a defect has occurred in the specimen TM (step S190).

[0112] If the measurer determines that no defect has occurred in the specimen TM (step S190-NO), the process proceeds to step S200.

[0113] On the other hand, if the measurer determines that a defect has occurred in the specimen TM (step S190-YES), the measurer records information indicating the defect that has occurred in the specimen TM (step S230). Note that the method for recording the information in step S230 may be any method that can record the information. After the processing of step S230 is performed, the measurer proceeds to step S200.

[0114] In step S200, the measurer determines whether or not to end the second radiated immunity test started in step S170 (step S200). In FIG. 7, the procedure of step S200 is indicated by "Test End?". Here, for example, if the second radiated immunity test started in step S170 has been completed, the measurer determines to end the second radiated immunity test started in step S170. On the other hand, for example, if the second radiated immunity test started in step S170 has not been completed, the measurer determines not to end the second radiated immunity test started in step S170. Note that the determination in step S200 may be made by other methods.

[0115] If the measurer determines not to end the second radiated immunity test started in step S170 (step S200-NO), the process proceeds to step S190, where the measurer determines again whether or not a defect has occurred in the test piece TM.

[0116] On the other hand, if the measurer determines to end the second radiation immunity test started in step S170 (step S200-YES), the measurer ends the second radiation immunity test (step S210). Here, in step S210, the measurer operates, for example, the information processing device 14 to end the input of the RF signal to the second antenna 121. Then, the measurer ends the procedure of the flowchart shown in FIG.

[0117] As described above, the measurer must have the reflector box 10, the first antenna 111 that is installed in the reflector box 10 and that radiates electromagnetic waves having a frequency lower than the first resonant frequency of the reflector box 10, the second antenna 121 that is installed in the reflector box 10 and that radiates electromagnetic waves having a frequency equal to or higher than the first resonant frequency, the first power supply device 114 that is connected between a member having a ground potential and the first antenna 111 and that feeds power to the first antenna 111, the dummy load 112 that is connected between the member having the ground potential and the first antenna 111, and the first antenna 111 when electromagnetic waves are radiated from the second antenna 121. In a radiated immunity test using a hybrid method using an electromagnetic wave test apparatus 1 including a first power loss suppression unit 113 having an impedance according to an allowable value for power loss due to a noise generated by the noise, and a switching unit 116 including a first switching unit SW1 that switches a connection destination of the first antenna 111 between the dummy load 112 and the first power loss suppression unit 113, when radiating electromagnetic waves from the first antenna 111, the connection destination of the first antenna 111 is switched to the dummy load 112, and when radiating electromagnetic waves from the second antenna 121, the connection destination of the first antenna 111 is switched to the first power loss suppression unit 113. Furthermore, in the radiated immunity test, when radiating electromagnetic waves from the first antenna 111, the measurer switches the connection destination of the first antenna 111 to the first power feeding device 114, and when radiating electromagnetic waves from the second antenna 121, the connection destination of the first antenna 111 is switched to the second power loss suppression unit 115. This makes it possible to prevent an increase in power loss in the radiated immunity test.

[0118] The procedure of the flowchart shown in Figure 7 may be applied to a radiated immunity test in which an electric field of a certain frequency is applied to the test specimen TM, or to a radiated immunity test in which electric fields of each of a certain number of frequencies are applied to the test specimen TM.

[0119] Furthermore, when the first power loss suppression unit 113 and the second power loss suppression unit 115 are integrally configured, the electromagnetic wave test apparatus 1 described above may be configured to include an RF power divider 118 as shown in Fig. 8. Fig. 8 is a diagram showing a modified example of the connection between the first antenna 111 and the first power loss suppression unit 113. In the example shown in Fig. 8, the RF power divider 118 is connected between each of the first switching unit SW1 and the second switching unit SW2 and the first power loss suppression unit 113. Even with this configuration, the electromagnetic wave test apparatus 1 can suppress an increase in power loss in a radiation immunity test using the hybrid method.

[0120] Furthermore, as mentioned above, the first antenna 111 described above may be a stripline as shown in FIG. 9 instead of a TEM plate antenna. FIG. 9 is a diagram showing an example of the state of the first antenna 111 connected to a stripline. A stripline is an antenna that applies an electric field to a test piece TM using the inside of a parallel plate. When the first antenna 111 is a stripline, the floor of the reflector box 10 is often used as the member having the ground potential described above, for example, by using a cable, a metal grounding jig, or the like.

[0121] Furthermore, as mentioned above, the first antenna 111 described above may be a septum as shown in Fig. 10 instead of a TEM plate antenna. Fig. 10 is a diagram showing an example of the state of the first antenna 111 connected to a septum. When the first antenna 111 is a septum, for example, the side surface of the reflective box 10 is often used as the component having the ground potential described above.

[0122] Here, first antenna 111 may be an antenna made up of a plurality of conducting wires, a plurality of flat plates, etc., instead of a flat plate-shaped antenna, as shown in Fig. 11. Fig. 11 is a diagram showing an example of first antenna 111 made up of a plurality of conducting wires, a plurality of flat plates, etc.

[0123] As described above, the electromagnetic wave test apparatus according to the embodiment (electromagnetic wave test apparatus 1 in the example described above) includes a reflection box (reflection box 10 in the example described above), a first antenna (first antenna 111 in the example described above) that is installed in the reflection box and that radiates electromagnetic waves having a frequency lower than the first resonance frequency of the reflection box, a second antenna (second antenna 121 in the example described above) that is installed in the reflection box and that radiates electromagnetic waves having a frequency equal to or higher than the first resonance frequency, a power supply device (first power supply device 114 in the example described above) that is connected between a member having a ground potential and the first antenna and that supplies power to the first antenna, and a dummy load (top In the example described above, the electromagnetic wave testing apparatus includes a dummy load 112), a first power loss suppression unit (first power loss suppression unit 113) having impedances (first impedance I11, second impedance I12, first impedance I21, and second impedance I22 in the example described above) corresponding to allowable values ​​(first allowable value and second allowable value in the example described above) for power loss by the first antenna when electromagnetic waves are radiated from the second antenna, and a switching unit (switching unit 116 in the example described above) including a first switching unit (first switching unit SW1 in the example described above) that switches the connection destination of the first antenna to either the dummy load or the first power loss suppression unit. This makes it possible for the electromagnetic wave testing apparatus to suppress an increase in power loss in a radiated immunity test using the hybrid method.

[0124] Furthermore, the electromagnetic wave testing device may have a configuration in which the first power loss suppressing section is an open end.

[0125] Furthermore, the electromagnetic wave testing device may have a configuration in which the first power loss suppressing section is a termination resistor.

[0126] Furthermore, the electromagnetic wave testing device may be configured such that the first power loss suppressing section is a member having a ground potential.

[0127] In addition, in the electromagnetic wave testing device, the switching unit may further include a third switching unit (first switching unit SW1 in the example described above) that switches the connection destination of the first antenna between the power supply device and the first power loss suppression unit.

[0128] The electromagnetic wave testing apparatus includes a reflection box, a first antenna installed in the reflection box and radiating electromagnetic waves having a frequency lower than a first resonant frequency of the reflection box, a second antenna installed in the reflection box and radiating electromagnetic waves having a frequency equal to or higher than the first resonant frequency, a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna, a second power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna and different from an open end, and a switching unit including a second switching unit (second switching unit SW2 in the example described above) that switches the connection destination of the first antenna to either the power supply device or the second power loss suppression unit (second power loss suppression unit 115 in the example described above). This allows the electromagnetic wave testing apparatus to suppress an increase in power loss in a radiation immunity test using a hybrid method.

[0129] Furthermore, the electromagnetic wave testing device may have a configuration in which the second power loss suppressing section is a termination resistor.

[0130] Furthermore, the electromagnetic wave testing device may be configured such that the second power loss suppression section is a member having a ground potential.

[0131] Furthermore, the electromagnetic wave testing device may be configured such that the impedance is a first impedance less than a first threshold value predetermined according to the tolerance, or a second impedance greater than or equal to a second threshold value predetermined according to the tolerance, the second threshold value being higher than the first threshold value.

[0132] In addition, the electromagnetic wave testing device may be configured such that the first impedance is an impedance that satisfies a first condition based on the allowable value, the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflection box, and the characteristic impedance of the first antenna, and the second impedance is an impedance that satisfies a second condition based on the allowable value, the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflection box, and the characteristic impedance of the first antenna.

[0133] In addition, in the electromagnetic wave test equipment, the first condition is expressed by the above formula (13), the second condition is expressed by the above formula (14), and r E indicates the tolerance, and r S A configuration may be used in which Z denotes the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflector box, and Z denotes the characteristic impedance of the first antenna.

[0134] In addition, in the electromagnetic wave test equipment, the first condition is expressed by the above formula (15), the second condition is expressed by the above formula (16), and r E indicates the tolerance, and r S A configuration may be used in which Z denotes the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflector box, and Z denotes the characteristic impedance of the first antenna.

[0135] and a switching unit including: a first switching unit that switches the connection destination of the first antenna between the dummy load and the first power loss suppression unit; a second switching unit that switches the connection destination of the first antenna between the power supply unit and the second power loss suppression unit; and a combined impedance of the impedance of the first power loss suppression unit and the impedance of the second power loss suppression unit, the combined impedance being an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna. This allows the electromagnetic wave testing device to prevent an increase in power loss during a radiation immunity test using the hybrid method.

[0136] Furthermore, the electromagnetic wave testing device may be configured such that the first power loss suppression section and the second power loss suppression section are open ends.

[0137] Furthermore, the electromagnetic wave testing device may be configured such that the first power loss suppressing section and the second power loss suppressing section are terminating resistors.

[0138] Furthermore, the electromagnetic wave testing device may be configured such that the first power loss suppression section and the second power loss suppression section are members having a ground potential.

[0139] The electromagnetic wave testing device may also have an operation unit or configuration that accepts an operation to cause the switching unit to switch the connection.

[0140] The electromagnetic wave testing device may also use a control device (first control device 117 in the example described above) that switches the connection to the switching unit.

[0141] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and may be changed, replaced, deleted, etc., without departing from the gist of the present invention. [Explanation of symbols]

[0142] REFERENCE SIGNS LIST 1...electromagnetic wave testing equipment, 10...reverberation chamber, 11...first testing equipment, 12...second testing equipment, 13...electromagnetic stirrer, 14...information processing device, 111...first antenna, 112...dummy load, 113...first power loss suppression unit, 114...first power feeding device, 115...second power loss suppression unit, 116...switching unit, 117...first control device, 118...RF power divider, 121...second antenna, 122...second power feeding device, 123...second control device, SW1...first switching unit, SW2...second switching unit, TM...test piece, X...resistance element

Claims

1. A reflective box and a first antenna installed in the reflection box and configured to radiate electromagnetic waves having a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and configured to radiate electromagnetic waves having a frequency equal to or higher than the first resonance frequency; a power supply device connected between a member having a ground potential and the first antenna and configured to supply power to the first antenna; a dummy load connected between the member having the ground potential and the first antenna; a first power loss suppression unit having an impedance according to an allowable value for power loss caused by the first antenna when electromagnetic waves are radiated from the second antenna; a switching unit including a first switching unit that switches a connection destination of the first antenna between the dummy load and the first power loss suppression unit; An electromagnetic wave testing device comprising:

2. The first power loss suppression unit has an open end.

2. The electromagnetic wave testing device according to claim 1.

3. the first power loss suppression unit is a termination resistor, the impedance of the dummy load matches the characteristic impedance of the first antenna; the impedance of the termination resistor does not match the characteristic impedance of the first antenna; 2. The electromagnetic wave testing device according to claim 1.

4. the first power loss suppression unit is a member having the ground potential, 2. The electromagnetic wave testing device according to claim 1.

5. the switching unit further includes a third switching unit that switches a connection destination of the first antenna between the power feeding device and the first power loss suppression unit.

5. The electromagnetic wave testing device according to claim 1.

6. A reflective box and a first antenna installed in the reflection box and configured to radiate electromagnetic waves having a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and configured to radiate electromagnetic waves having a frequency equal to or higher than the first resonance frequency; a power supply device connected between a member having a ground potential and the first antenna and configured to supply power to the first antenna; a second power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna, the second power loss suppression unit having an impedance different from an open end; a switching unit including a second switching unit that switches the connection destination of the first antenna between the power feeding device and the second power loss suppression unit; An electromagnetic wave testing device comprising:

7. the second power loss suppression unit is a termination resistor.

7. The electromagnetic wave testing device according to claim 6.

8. the second power loss suppression unit is a member having the ground potential, 7. The electromagnetic wave testing device according to claim 6.

9. the impedance is a first impedance less than a first threshold value predetermined according to the tolerance, or a second impedance equal to or greater than a second threshold value predetermined according to the tolerance, The second threshold is higher than the first threshold.

9. The electromagnetic wave testing device according to claim 1.

10. the first impedance is an impedance that satisfies a first condition based on the tolerance, a ratio of a surface area of ​​the first antenna to a surface area of ​​the reflector box, and a characteristic impedance of the first antenna; the second impedance is an impedance that satisfies a second condition based on the tolerance, a ratio of a surface area of ​​the first antenna to a surface area of ​​the reflector box, and a characteristic impedance of the first antenna.

10. The electromagnetic wave testing device according to claim 9.

11. The first condition is expressed by the following formula (1): [Equation 1] The second condition is expressed by the following formula (2): [Equation 2] rE indicates the tolerance, rS denotes the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflector box; Z0 represents the characteristic impedance of the first antenna; 11. The electromagnetic wave testing device according to claim 10.

12. The first condition is expressed by the following formula (3): [Equation 3] The second condition is expressed by the following formula (4): [Equation 4] rE indicates the tolerance, rS denotes the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflector box; Z0 represents the characteristic impedance of the first antenna; 11. The electromagnetic wave testing device according to claim 10.

13. A reflective box and a first antenna installed in the reflection box and configured to radiate electromagnetic waves having a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and configured to radiate electromagnetic waves having a frequency equal to or higher than the first resonance frequency; a power supply device connected between a member having a ground potential and the first antenna and configured to supply power to the first antenna; a dummy load connected between the member having the ground potential and the first antenna; a first power loss suppression unit having a predetermined impedance; a second power loss suppression unit having a predetermined impedance; a switching unit including a first switching unit that switches a connection destination of the first antenna between the dummy load and the first power loss suppression unit, and a second switching unit that switches a connection destination of the first antenna between the power feeding device and the second power loss suppression unit; Equipped with a combined impedance of the impedance of the first power loss suppression unit and the impedance of the second power loss suppression unit is an impedance according to an allowable value for power loss caused by the first antenna when electromagnetic waves are radiated from the second antenna; Electromagnetic wave testing equipment.

14. the first power loss suppression unit and the second power loss suppression unit are open ends.

14. The electromagnetic wave testing device according to claim 13.

15. the first power loss suppression unit and the second power loss suppression unit are termination resistors, the impedance of the dummy load matches the characteristic impedance of the first antenna; the impedance of the termination resistor does not match the characteristic impedance of the first antenna; 14. The electromagnetic wave testing device according to claim 13.

16. the first power loss suppression unit and the second power loss suppression unit are members having the ground potential, 14. The electromagnetic wave testing device according to claim 13.

17. the composite impedance is a first impedance less than a first threshold value predetermined according to the tolerance, or a second impedance equal to or greater than a second threshold value predetermined according to the tolerance, The second threshold is higher than the first threshold.

17. The electromagnetic wave testing device according to claim 13.

18. the first impedance is an impedance that satisfies a first condition based on the tolerance, a ratio of a surface area of ​​the first antenna to a surface area of ​​the reflector box, and a characteristic impedance of the first antenna; the second impedance is an impedance that satisfies a second condition based on the tolerance, a ratio of a surface area of ​​the first antenna to a surface area of ​​the reflector box, and a characteristic impedance of the first antenna.

18. The electromagnetic wave testing device according to claim 17.

19. The first condition is expressed by the following formula (5): [Equation 5] The second condition is expressed by the following formula (6): [Equation 6] rE indicates the tolerance, rS denotes the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflector box; Z0 represents the characteristic impedance of the first antenna; 19. The electromagnetic wave testing device according to claim 18.

20. The first condition is expressed by the following formula (7): [Equation 7] The second condition is expressed by the following formula (8): [Equation 8] rE indicates the tolerance, rS denotes the ratio of the surface area of ​​the first antenna to the surface area of ​​the reflector box; Z0 represents the characteristic impedance of the first antenna; 19. The electromagnetic wave testing device according to claim 18.

21. an operation unit that accepts an operation to cause the switching unit to switch the connection; 21. The electromagnetic wave testing device according to claim 1, further comprising:

22. a control device that causes the switching unit to switch the connection; 21. The electromagnetic wave testing device according to claim 1, further comprising:

23. an electromagnetic wave testing method using an electromagnetic wave testing device including: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves having a frequency lower than a first resonance frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves having a frequency equal to or higher than the first resonance frequency; a power feeding device connected between a member having a ground potential and the first antenna and feeding power to the first antenna; a dummy load connected between the member having the ground potential and the first antenna; a first power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna; and a switching unit including a first switching unit switching a connection destination of the first antenna to either the dummy load or the first power loss suppression unit, When radiating electromagnetic waves from the first antenna, the connection destination of the first antenna is switched to the dummy load, and when radiating electromagnetic waves from the second antenna, the connection destination of the first antenna is switched to the first power loss suppression unit. Electromagnetic wave test methods.

24. an electromagnetic wave testing method using an electromagnetic wave testing device including: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves having a frequency lower than a first resonance frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves having a frequency equal to or higher than the first resonance frequency; a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna; a second power loss suppression unit having an impedance according to an allowable value for power loss by the first antenna when electromagnetic waves are radiated from the second antenna and different from an open end; and a switching unit including a second switching unit switching a connection destination of the first antenna to either the power supply device or the second power loss suppression unit, When radiating electromagnetic waves from the first antenna, the connection destination of the first antenna is switched to the power supply device, and when radiating electromagnetic waves from the second antenna, the connection destination of the first antenna is switched to the second power loss suppression unit. Electromagnetic wave test methods.

25. an electromagnetic wave testing method using an electromagnetic wave testing device including: a reflection box; a first antenna installed in the reflection box and radiating electromagnetic waves having a frequency lower than a first resonant frequency of the reflection box; a second antenna installed in the reflection box and radiating electromagnetic waves having a frequency equal to or higher than the first resonant frequency; a power supply device connected between a member having a ground potential and the first antenna and supplying power to the first antenna; a dummy load connected between the member having the ground potential and the first antenna; a first power loss suppression unit; a second power loss suppression unit; and a switching unit including a first switching unit that switches a connection destination of the first antenna between the dummy load and the first power loss suppression unit, and a second switching unit that switches a connection destination of the first antenna between the power supply device and the second power loss suppression unit, a composite impedance of the impedance of the first power loss suppression unit and the impedance of the second power loss suppression unit is an impedance according to an allowable value for power loss caused by the first antenna when electromagnetic waves are radiated from the second antenna, The electromagnetic wave testing method includes: When radiating electromagnetic waves from the first antenna, the first switching unit switches a connection destination of the first antenna from the first power loss suppression unit to the dummy load, and the second switching unit switches a connection destination of the first antenna from the second power loss suppression unit to the power supply device, When radiating electromagnetic waves from the second antenna, the first switching unit switches the connection destination of the first antenna from the dummy load to the first power loss suppression unit, and the second switching unit switches the connection destination of the first antenna from the power supply device to the second power loss suppression unit. Electromagnetic wave test methods.

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