WO2021111737A1 - Electromagnetic wave measurement device and electromagnetic wave measurement method - Google Patents

Abstract

This electromagnetic wave measurement device comprises a housing, a first antenna for radiating electromagnetic waves corresponding to an acquired electrical signal, a second antenna for detecting the electric field strength of an electric field and outputting a voltage corresponding to the detected electric field strength, a third antenna for detecting the electric field strength of an electric field and outputting a voltage corresponding to the detected electric field strength, and an electromagnetic stirrer for stirring electromagnetic waves within the housing. The first antenna and third antenna are disposed inside the housing and outside of a prescribed effective space within the housing, and the second antenna is disposed inside the housing within the effective space.

Description

Electromagnetic wave measuring device and electromagnetic wave measuring method

The present invention relates to an electromagnetic wave measuring device and an electromagnetic wave measuring method.
The present application claims priority based on Japanese Patent Application No. 2019-22109 filed in Japan on December 06, 2019, the contents of which are incorporated herein by reference.

Research and development are being conducted on a method using a reflective box for measuring electromagnetic waves emitted from electronic devices.

In this regard, an electromagnetic wave measurement method using a housing, an electromagnetic stirrer, a transmitting antenna arranged outside a predetermined effective space inside the housing, and a receiving antenna arranged in the effective space. , An electromagnetic wave measuring method for measuring an electromagnetic wave radiated from an electronic device arranged in an effective space is known (see Non-Patent Document 1). The effective space is a space in which the electric field strength becomes uniform by stirring electromagnetic waves with an electromagnetic stirrer. Further, the measurement related to the electromagnetic wave includes, for example, measurement of the radiant power of the electronic device, measurement of the intensity of the electromagnetic wave, and the like.

Here, in the electromagnetic wave measurement method described in Non-Patent Document 1, the smaller the volume occupied by the receiving antenna among the volumes in the effective space, the larger the electronic device can be arranged in the effective space. It is desirable in the electromagnetic wave measurement method that a larger electronic device can be arranged in the effective space because the types of electronic devices to be measured for electromagnetic waves can be increased. However, the intensity of the electromagnetic wave radiated from the electronic device is often weaker than the intensity of the electromagnetic wave radiated from the transmitting antenna. In the electromagnetic wave measurement method, it is necessary to increase the sensitivity of the receiving antenna as the intensity of the electromagnetic wave radiated from the electronic device becomes weaker. As a result, in the electromagnetic wave measurement method, it may be necessary to increase the size of the receiving antenna. That is, in the electromagnetic wave measurement method, it may be difficult to reduce the volume occupied by the receiving antenna among the volumes in the effective space.

The present invention has been made in consideration of such circumstances, and it is an object of the present invention to provide an electromagnetic wave measuring device and an electromagnetic wave measuring method capable of reducing the volume occupied by the antenna among the volumes in the effective space. And.

One aspect of the present invention includes a housing, a first antenna that emits an electromagnetic wave corresponding to an acquired electric signal, and a second antenna that detects the electric field strength of an electric field and outputs a voltage corresponding to the detected electric field strength. The first antenna and the third antenna are provided with a third antenna that detects the electric field strength of the electric field and outputs a voltage corresponding to the detected electric field strength, and an electromagnetic stirrer that stirs the electromagnetic waves in the housing. Is an electromagnetic wave measuring device installed in the housing and outside a predetermined effective space in the housing, and the second antenna is installed in the effective space in the housing.

According to the present invention, the volume occupied by the antenna among the volumes in the effective space can be reduced.

It is a figure which shows an example of the structure of the electromagnetic wave measuring apparatus 1 which concerns on embodiment. It is a figure which shows an example of the flow of the method of measuring the radiant power of the electronic device P using the electromagnetic wave measuring device 1. It is a figure which shows an example of the electromagnetic wave measuring apparatus 1 when the electric field probe PB is arranged in the effective space WV of the reference state. It is a figure which shows an example of the electromagnetic wave measuring apparatus 1 when the electronic device P is arranged in the effective space WV of the reference state. It is a figure which shows an example of the equivalent circuit of the electromagnetic wave measurement system X. It is a figure which shows an example of the equivalent circuit of the electromagnetic wave measurement system X in the case where the characteristic of radio wave propagation of a space in a housing 11 _{is represented by a chamber gain G c.} It is a figure which shows another example of the equivalent circuit of the electromagnetic wave measurement system X in the case where the characteristic of radio wave propagation of a space in a housing 11 _{is represented by a chamber gain G c.} It is a figure which shows an example of the equivalent circuit of the electromagnetic wave measurement system shown in FIG. It is a figure which shows an example of the structure of the electromagnetic wave measuring apparatus 1 which concerns on the modification of embodiment.

<Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, for convenience of explanation, detecting the electric field strength of a certain electric field EF1 will be referred to as detecting the electric field EF1. Further, in the following, for convenience of explanation, the detected electric field strength will be referred to as a detected electric field EF1. Further, in the following, the measurement of a certain physical quantity means the detection of the physical quantity or the calculation of the physical quantity.

<Construction of reflective box>
First, the configuration of the electromagnetic wave measuring device 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an example of the configuration of the electromagnetic wave measuring device 1 according to the embodiment.

The electromagnetic wave measuring device 1 includes, for example, a housing 11 of the electromagnetic wave measuring device 1, an electromagnetic stirrer 12, a first antenna A1, and a second antenna A2. The electromagnetic wave measuring device 1 may be configured to include other devices, other members, and the like in addition to the housing 11, the electromagnetic stirrer 12, the first antenna A1 and the second antenna A2.

The electromagnetic wave measuring device 1 is, for example, a reflection box. The electromagnetic wave measuring device 1 is a device used for measuring electromagnetic waves radiated from an electromagnetic wave source arranged in a housing 11. Examples of the measurement include measurement of the radiated power of an electronic device arranged as an electromagnetic wave source in the housing 11, measurement of the intensity of radiant interfering waves radiated by the electronic device, and the like. Hereinafter, as an example, a case where the electromagnetic wave source arranged in the housing 11 is an electronic device P will be described. The electronic device P is not shown in FIG. 1 but is shown in FIG. The electromagnetic wave source (for example, the electronic device P) arranged in the housing 11 is an example of the object to be measured.

The housing 11 is a container for accommodating each member included in the electromagnetic wave measuring device 1. An electronic device P is also arranged in the housing 11.

The electromagnetic stirrer 12 agitates the electromagnetic waves in the housing 11. As a result, the electromagnetic stirrer 12 makes the electric field strength of the electric field in the predetermined effective space WV in the housing 11 uniform. Here, the effective space WV is a part of the space inside the housing 11. The effective space WV is a space in which the electric field strength becomes uniform due to the stirring of electromagnetic waves by the electromagnetic stirrer 12. In other words, the effective space WV is a space in which the amount of variation in the electric field strength due to the agitation of electromagnetic waves by the electromagnetic stirrer 12 is less than a predetermined amount. The method of stirring the electromagnetic wave by the electromagnetic stirrer 12 for making the electric field strength of the electric field in the effective space WV uniform may be a known method or a method to be developed in the future. Further, the shape of the electromagnetic stirrer 12 may be any shape as long as it can agitate the electromagnetic waves in the effective space WV and make the electric field strength of the electric field in the effective space WV uniform.

The first antenna A1 is an antenna that radiates an electromagnetic wave corresponding to an input electric signal. Further, the first antenna A1 is an antenna having reversibility. Therefore, the first antenna A1 can also be used as an antenna that detects an electric field and outputs a voltage corresponding to the detected electric field. Therefore, in the embodiment, the first antenna A1 is also used as an antenna that detects an electric field and outputs a voltage corresponding to the detected electric field. That is, in the embodiment, the first antenna A1 is an antenna that has reversibility and is used for both radiation of electromagnetic waves and detection of electric fields. The first antenna A1 may be an antenna used only for radiating electromagnetic waves. In this case, the electromagnetic wave measuring device 1 further includes a third antenna. The third antenna is an antenna used only for detecting an electric field. Details of the case where the electromagnetic wave measuring device 1 includes the third antenna will be described in a modified example of the embodiment.

The first antenna A1 is installed inside the housing 11 and outside the effective space WV. Here, in the example shown in FIG. 1, the first antenna A1 is connected to the information processing device 2. Therefore, in this example, the first antenna A1 acquires an electric signal from the information processing device 2 and emits an electromagnetic wave corresponding to the acquired electric signal. Further, in this example, the first antenna A1 detects an electric field. Then, in this example, the first antenna A1 outputs an electric signal indicating a voltage corresponding to the detected electric field to the information processing device 2. The first antenna A1 may be connected to the information processing device 2 via another device separate from the information processing device 2. The other device is a transmitter that causes the first antenna A1 to emit electromagnetic waves in response to a request from the information processing device 2, and information on the voltage acquired from the first antenna A1 in response to a request from the information processing device 2. It is a receiver or the like that outputs to the processing device 2. In the example shown in FIG. 1, the information processing device 2 is integrally configured with the other device.

The information processing device 2 is, for example, a desktop PC (Personal Computer). The information processing device 2 may be another information processing device such as a notebook PC, a tablet PC, a multifunctional mobile phone terminal (smartphone), a mobile phone terminal, or a PDA (Personal Digital Assistant).

The information processing device 2 outputs an electric signal to the first antenna A1 so that an electromagnetic wave in a wavelength band desired by the user is radiated from the first antenna A1 in response to an operation received from the user. Further, the information processing apparatus 2 acquires an electric signal indicating a voltage corresponding to the electric field detected by the first antenna A1 from the first antenna A1 in response to the operation received from the user. In the embodiment, the electromagnetic wave measuring device 1 is not provided with the information processing device 2, but may be provided with the information processing device 2 instead.

The second antenna A2 is an antenna that detects an electric field and outputs a voltage corresponding to the detected electric field. The second antenna A2 is installed in the effective space WV in the housing 11. Here, in the example shown in FIG. 1, the second antenna A2 is connected to the receiving device 3. Therefore, in this example, the second antenna A2 outputs an electric signal indicating a voltage corresponding to the detected electric field to the receiving device 3.

The receiving device 3 is connected to the information processing device 2 in a communicable manner by wire or wirelessly. The receiving device 3 acquires the electric signal output from the second antenna A2 from the second antenna A2. The receiving device 3 outputs the acquired electric signal to the information processing device 2. Therefore, the information processing device 2 acquires an electric signal from the receiving device 3. The receiving device 3 may be integrally configured with the information processing device 2. Further, in the embodiment, the electromagnetic wave measuring device 1 is not provided with the receiving device 3, but may be provided with the receiving device 3 instead.

As described above, the electromagnetic wave measuring device 1 having the above configuration is used for measuring the electromagnetic waves radiated by the electronic device P arranged in the housing 11.

<Method of measuring electromagnetic waves radiated by an electronic device using an electromagnetic wave measuring device> Hereinafter, a method of measuring electromagnetic waves radiated by an electronic device P using an electromagnetic wave measuring device 1 will be described. In the following, as an example, a case where the measurement is a measurement of the radiant power of the electronic device P arranged in the effective space WV will be described. Further, in the following, for convenience of explanation, the user of the electromagnetic wave measuring device 1 will be simply referred to as a user.

FIG. 2 is a diagram showing an example of a flow of a method of measuring the radiant power of the electronic device P using the electromagnetic wave measuring device 1.

Here, the user measures the conversion coefficient for converting the detected electric field into a voltage according to the procedure of step S110 and step S120 shown in FIG. That is, the procedure of step S110 and step S120 is a conversion coefficient measurement procedure. Therefore, in the method of measuring the electromagnetic wave radiated by the electronic device P using the electromagnetic wave measuring device 1, when the conversion coefficient has already been measured by another device, another method, or the like, the user steps S110 and step. The procedure of S120 may be omitted.

Further, the user measures the correction coefficient according to the procedure of steps S130 to S150 shown in FIG. This correction coefficient is a coefficient for correcting a conversion coefficient that may change depending on the presence or absence of the electronic device P in the effective space WV. Details of the correction coefficient will be described later. That is, the procedure of steps S130 to S150 is a correction coefficient measuring procedure. Therefore, when the user has already measured the correction coefficient by another device, another method, or the like, in the method of measuring the electromagnetic wave radiated by the electronic device P using the electromagnetic wave measuring device 1, steps S130 to step S The procedure of S150 may be omitted.

The user measures the radiant power of the electronic device P by the procedure of step S160 and step S170 shown in FIG. 2 using the conversion coefficient and the correction coefficient measured by the procedure of step S110 to step S150. Therefore, when the conversion coefficient and the correction coefficient have already been measured by another device, another method, or the like, the user can measure the radiant power of the electronic device P using the electromagnetic wave measuring device 1 in step S160 and step S160. Only the process of step S170 may be performed.

In the following, for convenience of explanation, a reference state among the states in the effective space WV will be referred to as a reference state. As for the reference state, for example, among the states in the effective space WV, as shown in FIG. 1, only the cable connecting the second antenna A2 and the receiving device 3 and the second antenna A2 are arranged in the effective space WV. It is the state of being done. The reference state may be any state as long as it is a state that can be realized as a state in the effective space WV.

The user performs the detection procedure D1 (step S110). Here, the detection procedure D1 will be described.

The detection procedure D1 radiates an electromagnetic wave to the first antenna A1 outside the effective space when the inside of the effective space WV is in the reference state, and detects the electric field in the effective space WV by the electric field probe PB in the effective space WV. The procedure. Here, the electric field in the effective space WV in the detection procedure D1 is an electric field corresponding to the electromagnetic wave radiated from the first antenna A1 outside the effective space. Therefore, in the detection procedure D1, the user arranges the electric field probe PB in the effective space WV in the reference state as shown in FIG. When the state in the effective space WV is not the reference state, for example, the user arranges the electric field probe PB in the effective space WV after setting the state in the effective space WV as the reference state. FIG. 3 is a diagram showing an example of the electromagnetic wave measuring device 1 when the electric field probe PB is arranged in the effective space WV in the reference state.

The electric field probe PB may be connected to the information processing device 2 or may be connected to the receiving device 3. Hereinafter, as an example, a case where the electric field probe PB is connected to the information processing device 2 will be described. However, in FIG. 3, the cable connecting the electric field probe PB and the information processing device 2 is omitted in order to prevent the figure from becoming complicated.

After arranging the electric field probe PB in the effective space WV in the reference state, in the detection procedure D1, the user operates the information processing device 2 to radiate an electromagnetic wave in a predetermined wavelength band to the first antenna A1. As a result, in the effective space WV, the electric field strength of the electric field corresponding to the electromagnetic wave radiated from the first antenna A1 becomes uniform due to the agitation of the electromagnetic wave by the electromagnetic stirrer 12. The electric field probe PB outputs an electric signal indicating a voltage corresponding to the electric field strength uniformed in the effective space WV in this way. Therefore, the information processing device 2 acquires the electric signal from the electric field probe PB. Based on the acquired electric signal, the information processing device 2 stores information indicating a voltage corresponding to the electric field strength in a storage unit (not shown) included in the information processing device 2 as second detection information. The user performs the detection procedure D1 as described above in step S110. In the following, for convenience of explanation, the electromagnetic wave in the predetermined wavelength band will be referred to as a radiated electromagnetic wave.

After the detection procedure D1 is performed in step S110, the user performs the calculation procedure C1 (step S120). Here, the calculation procedure C1 will be described.

The calculation procedure C1 is a procedure for calculating the above-mentioned conversion coefficient based on the voltage detected by the detection procedure D1 in step S110. The method of calculating the conversion coefficient based on the voltage detected by the detection procedure D1 in step S110 may be a known method or a method to be developed in the future. For example, in the calculation procedure C1, the user operates the information processing device 2 and causes the information processing device 2 to calculate the conversion coefficient based on the voltage indicated by the second detection information stored in the information processing device 2. That is, in the calculation procedure C1, the information processing device 2 reads out the second detection information stored in the storage unit according to the operation received from the user, and responds to the voltage indicated by the read second detection information and the radiated electromagnetic wave. The conversion coefficient is calculated based on the electric field strength of the generated electric field. Then, in the calculation procedure C1, the information processing apparatus 2 stores the conversion coefficient information indicating the calculated conversion coefficient in the storage unit. The electric field strength of the electric field according to the radiated electromagnetic wave is calculated or detected in advance, for example.

After the calculation procedure C1 is performed in step S120, the user performs the detection procedure D2 (step S130). Here, the detection procedure D2 will be described.

In the detection procedure D2, when the inside of the effective space WV is in the reference state, the radiated electromagnetic wave is radiated to the first antenna A1 outside the effective space, and the voltage corresponding to the electric field strength of the electric field in the effective space WV is set to the effective space WV. This is the procedure for detecting with the second antenna A2 inside. Here, the electric field in the effective space WV in the detection procedure D2 is an electric field corresponding to the radiated electromagnetic wave radiated from the first antenna A1 outside the effective space. Therefore, in the detection procedure D2, the user sets the state in the effective space WV as the reference state. Then, in the detection procedure D2, the user operates the information processing device 2 to radiate the radiated electromagnetic wave to the first antenna A1. As a result, in the effective space WV, the electric field strength of the electric field corresponding to the radiated electromagnetic wave radiated from the first antenna A1 becomes uniform by the agitation of the radiated electromagnetic wave by the electromagnetic stirrer 12. The second antenna A2 outputs an electric signal indicating a voltage corresponding to the electric field strength that has become uniform in the effective space WV in this way. Therefore, the receiving device 3 acquires the electric signal from the second antenna A2. The receiving device 3 outputs the acquired electric signal to the information processing device 2. The information processing device 2 acquires the electric signal from the receiving device 3. Based on the acquired electric signal, the information processing device 2 stores information indicating a voltage corresponding to the electric field strength in the storage unit of the information processing device 2 as third detection information. The user performs the detection procedure D2 as described above in step S130.

After the detection procedure D2 is performed in step S130, the user performs the detection procedure D3 (step S140). Here, the detection procedure D3 will be described.

In the detection procedure D3, the electronic device P is arranged in the effective space WV in the reference state, the radiated electromagnetic wave is radiated to the first antenna A1 outside the effective space, and the voltage corresponding to the electric field strength of the electric field in the effective space WV is set. This is a procedure for detecting by the second antenna A2 in the effective space WV. Here, the electric field in the effective space WV in the detection procedure D3 is an electric field corresponding to the radiated electromagnetic wave radiated from the first antenna A1 outside the effective space. Therefore, in the detection procedure D3, the user arranges the electronic device P in the effective space WV which is kept in the reference state in the detection procedure D2. When the state in the effective space WV is different from the reference state due to vibration, the movement of the user during work, etc., for example, the user sets the state in the effective space WV as the reference state and then sets the effective space. The electronic device P is arranged in the WV. FIG. 4 is a diagram showing an example of the electromagnetic wave measuring device 1 when the electronic device P is arranged in the effective space WV in the reference state.

After arranging the electronic device P in the effective space WV in the reference state, in the detection procedure D3, the user operates the information processing device 2 to radiate the radiated electromagnetic wave to the first antenna A1. As a result, in the effective space WV, the electric field strength of the electric field corresponding to the radiated electromagnetic wave radiated from the first antenna A1 becomes uniform due to the agitation of the electromagnetic wave by the electromagnetic stirrer 12. The second antenna A2 outputs an electric signal indicating a voltage corresponding to the electric field strength that has become uniform in the effective space WV in this way. Therefore, the receiving device 3 acquires the electric signal from the second antenna A2. The receiving device 3 outputs the acquired electric signal to the information processing device 2. The information processing device 2 acquires the electric signal from the receiving device 3. Based on the acquired electric signal, the information processing device 2 stores information indicating a voltage corresponding to the electric field strength in the storage unit of the information processing device 2 as fourth detection information. The user performs the detection procedure D3 as described above in step S130.

After the detection procedure D3 is performed in step S140, the user performs the calculation procedure C2 (step S150). Here, the calculation procedure C2 will be described.

The calculation procedure C2 is a procedure for calculating the above-mentioned correction coefficient based on the voltage detected by the detection procedure D2 in step S130 and the voltage detected by the detection procedure D3 in step S140. The method of calculating the correction coefficient based on the third detected electric field and the fourth detected electric field may be a known method or a method to be developed in the future. For example, in the calculation procedure C2, the user operates the information processing device 2 to calculate the correction coefficient based on the voltage indicated by each of the third detection information and the fourth detection information stored in the information processing device 2. Let the processing device 2 do this. That is, in the calculation procedure C2, the information processing device 2 reads out the third detection information and the fourth detection information stored in the storage unit according to the operation received from the user, and the read third detection information and the fourth detection information. The correction coefficient is calculated based on the voltage indicated by each of the information and the electric field strength of the electric field corresponding to the radiated electromagnetic wave. Then, in the calculation procedure C2, the information processing apparatus 2 stores the correction coefficient information indicating the calculated correction coefficient in the storage unit.

After the calculation procedure C2 is performed in step S150, the user performs the detection procedure D4 (step S160). Here, the detection procedure D4 will be described.

In the detection procedure D4, the electronic device P is arranged in the effective space WV in the reference state, the electronic device P is operated, and the voltage corresponding to the electric field strength of the electric field in the housing 11 is applied to the first antenna outside the effective space WV. This is the procedure for detecting by A1. Here, the electric field in the effective space WV in the detection procedure D4 is an electric field corresponding to the electromagnetic wave radiated from the electronic device P in the effective space WV. Therefore, in the detection procedure D4, the user sets the state in the effective space WV as the reference state. After that, in the detection procedure D4, the user operates the electronic device P to operate the electronic device P. As a result, in the effective space WV, the electric field strength of the electric field corresponding to the electromagnetic wave becomes uniform by the agitation of the electromagnetic wave by the electromagnetic stirrer 12. Then, the first antenna A1 outside the effective space WV outputs an electric signal indicating a voltage corresponding to the electric field strength of the electric field outside the effective space WV. Therefore, the information processing device 2 acquires the electric signal from the first antenna A1. Based on the acquired electric signal, the information processing device 2 stores information indicating a voltage corresponding to the electric field strength in the storage unit as first detection information. The user performs the detection procedure D4 as described above in step S160.

After the detection procedure D4 is performed in step S160, the user performs the calculation procedure C3 (step S170). Here, the calculation procedure C3 will be described.

The calculation procedure C3 is an electronic device based on the voltage detected by the detection procedure D4 in step S160, the conversion coefficient calculated by the calculation procedure C1 in step S120, and the correction coefficient calculated by the calculation procedure C2 in step S150. This is a procedure for calculating the radiant power of P. The method of calculating the radiant power based on the conversion coefficient, the correction coefficient, and the first detected electric field may be a known method or a method to be developed in the future. For example, the user operates the information processing device 2 and causes the information processing device 2 to calculate the radiated power based on each of the first detection information, the conversion coefficient information, and the correction coefficient information stored in the information processing device 2. Let me do it. That is, in the second calculation means, the information processing device 2 reads out and reads out each of the first detection information, the conversion coefficient information, and the correction coefficient information stored in the storage unit according to the operation received from the user. The radiated power is calculated based on the voltage indicated by the detection information, the conversion coefficient indicated by the read conversion coefficient information, and the correction coefficient indicated by the read correction coefficient information. Then, in the calculation procedure C3, the information processing device 2 stores the calculated radiant power information indicating the radiant power in the storage unit.

After the calculation procedure C3 is performed in step S170, the user ends the measurement of the radiant power of the electronic device P using the electromagnetic wave measuring device 1.

Note that, in the flowchart shown in FIG. 2, the detection means D1 may be configured to be performed in parallel with the detection means D2. In this case, in the detecting means D2, the state in the effective space WV may be the same as the state in the effective space WV in the detecting means D1. That is, in this case, in the detection means D2, the state in the effective space WV may be the state in which the electric field probe PB is still arranged. This is because the existence of the electric field probe PB in the effective space WV is small with respect to the wavelength of the electromagnetic wave transmitted and received in the effective space WV, so that it is considered that the electric field in the effective space WV is not disturbed. .. Under such circumstances, even in the detection procedure D3 and the detection procedure D4, the state in the effective space WV may be the state in which the electric field probe PB is still arranged. Further, if the electric field probe PB is arranged in the effective space WV in all of the detection procedures D1 to D4, the reference state described above may be defined as the state in which the electric field probe PB is arranged. ..

As described above, the user measures the radiant power of the electronic device P using the electromagnetic wave measuring device 1 by performing each procedure included in the flowchart shown in FIG. Here, in step S160 described above, the first antenna A1 is used as the antenna for detecting the electric field. More specifically, in the flowchart, the first antenna A1 used as an antenna for radiating electromagnetic waves in steps S130 and S140 is used as an antenna for detecting an electric field in step S160. This is equivalent to exchanging the roles of the circuit on the transmitting side and the role of the circuit on the receiving side in the equivalent circuit representing the electromagnetic wave measurement system shown in FIG. When the first antenna A1 has reversibility, such replacement of roles is possible. Therefore, in the following, when the first antenna A1 has reversibility, the principle that such roles can be exchanged will be described. Further, in the following, for convenience of explanation, the principle will be referred to as a replaceable principle.

<Replaceable principle>
The replaceable principle will be described below. In order to explain the replaceable principle, there is a case where a certain antenna X1 that radiates electromagnetic waves is installed outside the effective space WV in the housing 11, and a certain antenna X2 that detects an electric field is effective in the housing 11. Consider the case where it is installed in the space WV. In this case, in the housing 11, the antenna X1 radiates an electromagnetic wave corresponding to the input electric signal. Further, in the housing 11, the antenna X2 detects the electric field strength of the electric field in the housing 11 and outputs a voltage corresponding to the detected electric field strength. Therefore, in this case, the equivalent circuit of the electromagnetic wave measurement system X composed of the antenna X1 and the antenna X2 is the circuit as shown in FIG. FIG. 5 is a diagram showing an example of an equivalent circuit of the electromagnetic wave measurement system X.

Here, the equivalent circuit shown in FIG. 5 is a two-terminal pair circuit. Hereinafter, for convenience of explanation, among the circuits included in the equivalent circuit, the circuit surrounded by the dotted line TC will be referred to as a transmission side circuit. The transmitting side circuit is a circuit corresponding to the antenna X1. Further, in the following, for convenience of explanation, among the circuits included in the equivalent circuit, the circuit surrounded by the dotted line RC will be referred to as a receiving side circuit. The receiving side circuit is a circuit corresponding to the antenna X2.

_{R 0} shown in FIG. 5 indicates the characteristic impedance of the transmitting side circuit. _{Further, V 0} shown in FIG. 5 indicates a power source for supplying AC power to the transmitting side circuit. _{Further, Rr} shown in FIG. 5 indicates the characteristic impedance of the receiving side circuit. Further, each component of the matrix shown in FIG. 5 (that is, Z ₁₁ , Z ₁₂ , Z ₂₁ , Z ₂₂ ) is a Z parameter of the electromagnetic wave measurement system X. S parameters of the electromagnetic wave measuring system X _(i.e., S _{11, S 12,} S _{21, S 22)} can be calculated by using the Z parameter. Then, S ₁₂ of the S parameters is calculated by the following equation (1). Since the description of the amount of each component of the Z parameter and the S parameter is known, the description thereof will be omitted.

_{It is considered that Z 12} included in the above equation (1) is proportional to the effective length l _r of the antenna X2 and inversely proportional to _{the directional gain G d} of the antenna X2 due to the nature of the reflection box. Therefore, if the component that remains when the contribution of the effective length l _r and directional gain G _d were excluded from Z ₁₂ and Z _{12 ',} Z ₁₂ can be expressed as the following equation (2).

Here, assuming that the coupling between the antenna X1 and the antenna X2 is sufficiently small, the following equation (3) holds.

Then, the following equation (4) can be derived from the above equations (2) and (3).

On the other hand, the antenna factor AF _r of the antenna X2 is defined by the following equation (5).

By substituting the above equation (5) into the equation (4), the following equation (6) can be derived.

Here, in the equivalent circuit shown in FIG. 5, the antenna X1 can be associated with the first antenna A1 and the antenna X2 can be associated with the electric field probe PB. In this case, the equivalent circuit can be considered as an equivalent circuit of the electromagnetic wave measurement system composed of the first antenna A1 and the electric field probe PB in the electromagnetic wave measurement device 1 shown in FIG. In this case, the above-mentioned directional gain G _d is the directional gain of the dipole antenna. As the field probe PB used in step S110, the electric field probe PB that have already done calibration of antenna factor AF _r it is used. That is, the antenna factor AF _r of the field probe PB used in step S110 is a known quantity. Therefore, in this case, assuming that the antenna factor AF _r is calibrated to 1, the antenna factor AF _r can be eliminated from the equation (6). The amount remaining after the antenna factor AF _r is eliminated from the equation (6) in this way is the amount defined as the following equation (7) as the _{chamber gain G c.}

The chamber gain G _c defined in this way is the above-mentioned conversion coefficient. _{That is, in step S120, the user calculates the chamber gain G c} based on the voltage indicated by the second detection information as the conversion coefficient. By measuring the left side of the chamber the gain G _c of the above formula (7), the user, based on the above equation (7) can calculate the Z _{21 '.}

This chamber gain G _c is an amount obtained as a characteristic of the electromagnetic wave measuring device 1. In other words, the chamber gain G _c is a quantity representing the characteristics of radio wave propagation in the space inside the housing 11. That is, the way the electromagnetic wave propagates between the antenna X1 and the antenna X2 is characterized by _{the chamber gain G c.} Then, the electromagnetic wave is agitated in the housing 11 by the electromagnetic stirrer 12. Therefore, if the antenna X1 has reversibility, the method of propagating the electromagnetic wave between the antenna X1 and the antenna X2 is different even when the antenna X2 is changed from the electric field probe PB to another antenna. Characterized by chamber gain G _c. This means that in this case, reversibility is established between the electric field detected by the antenna X1 and the electric field detected by the antenna X2. When the electronic device P is placed in the reflection box, the chamber gain G _c may decrease. The coefficient for correcting the decrease in the chamber gain G _c , that is, the decrease in the conversion coefficient, is the above-mentioned correction coefficient.

Here, if the characteristics of radio wave propagation in space of the housing 11 is represented by the chamber gain G _c, the equivalent circuit shown in FIG. 5, rewritten as an equivalent circuit shown in FIG. FIG. 6 is a diagram showing an example of an equivalent circuit of the electromagnetic wave measurement system X when the characteristic of radio wave propagation in the space in the housing 11 _{is represented by the chamber gain G c.} In FIG. 6, the characteristic impedance Rr of the receiving side circuit is represented as 1 [Ω]. Further, when reversibility is established between the electric field detected by the antenna X1 and the electric field detected by the antenna X2, the two off-diagonal components of the matrix shown in FIG. 6 are equal to each other. From this, in the equivalent circuit shown in FIG. 6, the voltage V _r1 across the characteristic impedance of the receiving circuit is calculated by the following equation (8).

On the other hand, when the above-mentioned power source V ₀ is moved from the transmitting side circuit to the receiving side circuit, the equivalent circuit shown in FIG. 6 is rewritten as the equivalent circuit shown in FIG. 7. FIG. 7 is a diagram showing another example of the equivalent circuit of the electromagnetic wave measurement system X when the characteristic of radio wave propagation in the space in the housing 11 _{is represented by the chamber gain G c.} In the equivalent circuit shown in FIG. 7, the voltage V _r2 across the characteristic impedance of the receiving circuit is calculated by the following equation (9).

By comparing the above formula (8) and Equation (9), when the characteristics of radio wave propagation in space of the housing 11 is represented by the chamber gain G _c, and the electric field strength detected by the antenna X1, It can be seen that reversibility holds between the electric field strength detected by the antenna X2. That is, according to such a replaceable principle, in the flowchart shown in FIG. 2, the user reverses the role of the first antenna A1 in step S130 and step S140 and the role of the first antenna A1 in step S160. can do.

<Example of calculation method of radiant power of electronic equipment>
Hereinafter, an example of a method for calculating the radiant power of the electronic device P in step S170 shown in FIG. 2 will be described. As described above, the calculation of the radiant power is performed based on the voltage indicating the electric field detected by the first antenna A1 in step S160. Then, the detection of the electric field is performed in the electromagnetic wave measurement system shown in FIG. FIG. 8 is a diagram showing an example of an equivalent circuit of the electromagnetic wave measurement system shown in FIG.

_{R 0'shown in} FIG. 8 indicates the characteristic impedance of the first antenna A1. Also, V _s shown in FIG. 8 shows the output voltage of the electronic device P. _{Further, Z s} shown in FIG. 8 indicates the characteristic impedance of the electronic device P. Further, each component of the matrix shown in FIG. 8 is a Z parameter of the electromagnetic wave measurement system shown in FIG. _{Here, l s} shown in FIG. 8 indicates the effective length of the electronic device P. _{Further, G s} shown in FIG. 8 indicates the directional gain of the electronic device P.

In the equivalent circuit shown in FIG. 8, the voltage across V _r of the characteristic impedance Zs of the electronic device P is calculated by the following equation (10).

Incidentally, the voltage across V _r of the characteristic impedance Z _s of the electronic device P is the open circuit voltage in the electromagnetic measurement system shown in FIG. However, the voltage across V _r, as measured at a high frequency such as a spectrum analyzer, a generally termination voltage. Therefore, in this case, the voltage across the circuit _{is expressed} by the following equation (11).

Here, considering that it is a substitution method, the following equation (12) holds.

Then, the following equation (13) is derived from the above equations (11) and (12).

Further, also in the equivalent circuit shown in FIG. 8, the characteristic of radio wave propagation in the space inside the housing 11 is represented by _{the chamber gain G c.} Therefore, the off-diagonal components of the matrix shown in FIG. 8 are equal to each other. Then, the current _{I s} flowing through the characteristic impedance _{Z s} of the electronic device P _are the _{I s = V s / Z s} , the equation (13) is expressed by the following equation (14).

The above equation (14) can be expressed as the following equation (15) by reorganizing it.

Here, the effective length l _s is defined as the following equation (16).

Here, R shown in the above formula (16) indicates radiation resistance. Also, _{G a} shown in Equation (16) shows the absolute gain. Then, by multiplying the both sides to _{I s} of formula (16), of the formula (17) below is obtained.

W in the formula (17) above is the power that is calculated by W = R × _I ^{s 2,} that is, the radiated power of the electronic device P. Then, _{G a} W obtained by multiplying the absolute gain _{G a} in the W indicates the effective radiated power. This effective radiated power G _a W is the radiated power of the electronic device P calculated in step S170 shown in FIG.

The above equation (17) can be reorganized as the following equation (18).

Here, the right side of the above equation (18) is all known quantities except for _{the directional gain G s of the electronic device P.} That is, if the directional gain G _s of the electronic device P can be estimated by some method, the user can calculate the effective radiated power of the electronic device P by using the equation (18). For example, when the wavelength of the electromagnetic wave radiated from the electronic device P is sufficiently smaller than the size of the electronic device P, the directivity gain G _{s of the electronic device P is the directional gain G d} of the electric field probe PB. Become equal. Utilizing such a property, the user can calculate the effective radiated power of the electronic device P by using the equation (18).

The user can use the following equation (19) to estimate the electric field strength of the electric field corresponding to the electromagnetic wave radiated by the electronic device P at a position r away from the electronic device P. it can.

The electric field estimated in this way can be applied to, for example, the measurement of the intensity of the radiated disturbance of the electronic device P by the user.

In the embodiment described above, the antenna factor of the second antenna A2 may be equal to or higher than the antenna factor of the first antenna A1 (that is, the sensitivity of the second antenna A2 is equal to or lower than the sensitivity of the first antenna A1). May be). This is because the detection means D2 and the detection means D3 can increase the intensity of the electromagnetic wave radiated to the first antenna A1 by setting the information processing device 2, so that even if the sensitivity of the second antenna A2 is low, the second antenna A2 is second. This is because the antenna A2 can detect the electric field. Then, in the detection means D4, the electric field corresponding to the weak electromagnetic wave radiated from the electronic device P (the electromagnetic wave whose intensity cannot be further increased) is detected by the first antenna A1 and the second antenna. This is also because it is not necessary to detect by A2. From the above, the electromagnetic wave measuring device 1 can reduce the volume occupied by the second antenna among the volumes in the effective space. For the same reason, in the embodiment, when the first antenna A1 and the second antenna A2 are antennas having an element, the maximum length of the element of the second antenna A2 is the maximum length of the element of the first antenna A1. It may be as follows. Further, for the same reason, in the embodiment, when the first antenna A1 and the second antenna A2 are antennas having an opening surface, the maximum length of the opening surface of the second antenna A2 is the opening of the first antenna A1. It may be less than or equal to the maximum length of the surface.

Further, in the embodiment described above, the antenna that detects the electric field corresponding to the electromagnetic wave radiated from the electronic device P in step S160 is not the second antenna A2 but the first antenna A1. Therefore, the receiving device 3 connected to the second antenna A2 does not detect the electric field corresponding to the electromagnetic wave. From this, the noise floor of the receiving device 3 may have any value, and may be, for example, one-hundredth or more of the permissible value of the radiated power value for the electronic device P. When the receiving device 3 is integrally configured with the information processing device 2, the noise floor of the information processing device 2 may be 1/100 or more of the permissible value of the radiant power value for the electronic device P.

<Modified example of the embodiment>
Hereinafter, a modified example of the embodiment will be described with reference to FIG. FIG. 9 is a diagram showing an example of the configuration of the electromagnetic wave measuring device 1 according to the modified example of the embodiment. In the modified example of the embodiment, the same components as those in the embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the modified example of the embodiment, the first antenna A1 is an antenna that radiates an electromagnetic wave corresponding to the input electric signal. Then, in the modified example of the embodiment, the first antenna A1 is an antenna used only for radiating electromagnetic waves. Therefore, the electromagnetic wave measuring device 1 according to the modified example of the embodiment includes the role played by the first antenna A1 in the embodiment, that is, the third antenna A3 that detects the electric field.

The electromagnetic wave measuring device 1 according to the modified example of the embodiment includes, for example, a housing 11 of the electromagnetic wave measuring device 1, an electromagnetic stirrer 12, a first antenna A1, a second antenna A2, and a third antenna A3. The electromagnetic wave measuring device 1 may include other devices, other members, and the like in addition to the housing 11, the electromagnetic stirrer 12, the first antenna A1, the second antenna A2, and the third antenna A3. Good.

The third antenna A3 is an antenna that detects an electric field and outputs a voltage corresponding to the detected electric field. The third antenna A3 is installed in the effective space WV in the housing 11. Here, in the example shown in FIG. 1, the third antenna A3 is connected to the information processing device 2. Therefore, in this example, the third antenna A3 outputs an electric signal indicating a voltage corresponding to the detected electric field to the information processing device 2.

Here, when the user measures the radiant power of the electronic device P using the electromagnetic wave measuring device 1 according to the modified example of the embodiment by performing each procedure included in the flowchart shown in FIG. 2, step S160. In the above, the electric field is detected by the third antenna A3 instead of the first antenna A1. As a result, the electromagnetic wave measuring device 1 according to the modified example of the embodiment can obtain the same effect as the electromagnetic wave measuring device 1 according to the embodiment even in this case.

In the modified example of the embodiment described above, the antenna factor of the second antenna A2 may be equal to or higher than the antenna factor of the third antenna A3 (that is, the sensitivity of the second antenna A2 is higher than that of the third antenna A3). It may be less than or equal to the sensitivity of). This is because the antenna that detects the electric field corresponding to the electromagnetic wave radiated from the electronic device P in step S160 is not the second antenna A2 but the third antenna A3. Therefore, the electromagnetic wave measuring device 1 can reduce the volume occupied by the second antenna among the volumes in the effective space. For the same reason, in the modified example of the embodiment, when the second antenna A2 and the third antenna A3 are antennas having an element, the maximum length of the element of the second antenna A2 is the element of the third antenna A3. It may be less than or equal to the maximum length. Further, for the same reason, in the modified example of the embodiment, when the second antenna A2 and the third antenna A3 are antennas having an opening surface, the maximum length of the opening surface of the second antenna A2 is the third antenna. It may be less than or equal to the maximum length of the opening surface of A3.

Further, in the modified example of the embodiment described above, the antenna that detects the electric field corresponding to the electromagnetic wave radiated from the electronic device P in step S160 is not the second antenna A2 but the third antenna A3. Therefore, the receiving device 3 connected to the second antenna A2 does not detect the electric field corresponding to the electromagnetic wave. From this, the noise floor of the receiving device 3 may have any value, and may be, for example, one-hundredth or more of the permissible value of the radiated power value for the electronic device P. When the receiving device 3 is integrally configured with the information processing device 2, the noise floor of the information processing device 2 may be 1/100 or more of the permissible value of the radiant power value for the electronic device P.

As described above, the electromagnetic wave measuring device according to the embodiment has a housing and a first antenna (in the example described above) that emits an electromagnetic wave (radiated electromagnetic wave in the example described above) corresponding to the acquired electric signal. , The first antenna A1), the second antenna that detects the electric field strength of the electric field and outputs the voltage corresponding to the detected electric field strength (the second antenna A2 in the example described above), and the electric field strength of the electric field. A third antenna (in the example described above, the first antenna A1 or the third antenna A3) that detects and outputs a voltage corresponding to the detected electric field strength, and an electromagnetic stirrer that stirs the electromagnetic waves in the housing ( In the example described above, the electromagnetic stirrer 12) is provided, and the first antenna and the third antenna are inside the housing and outside a predetermined effective space (in the example described above, the effective space WV). The second antenna is installed in the effective space in the housing. As a result, the electromagnetic wave measuring device can reduce the volume occupied by the antenna (that is, the second antenna) in the effective space.

Further, in the electromagnetic wave measuring device, the configuration in which the third antenna is integrally configured with the first antenna may be used.

Further, in the electromagnetic wave measuring device, a configuration may be used in which the antenna factor of the second antenna is equal to or higher than the antenna factor of the third antenna.

Further, in the electromagnetic wave measuring device, the second antenna and the third antenna have elements, and the maximum length of the element of the second antenna is equal to or less than the maximum length of the element of the third antenna. May be done.

Further, in the electromagnetic wave measuring device, the second antenna and the third antenna have an opening surface, and the maximum length of the opening surface of the second antenna is equal to or less than the maximum length of the opening surface of the third antenna. The configuration may be used.

Further, the electromagnetic wave measuring device includes a receiving device connected to the second antenna, and the noise floor of the receiving device is one-hundredth or more of the permissible value of the radiant power value for the object to be measured that emits electromagnetic waves. May be used.

Further, in the electromagnetic wave measuring method, a configuration may be used in which the effective space is a space in the housing in which the electric field strength of the electric field becomes uniform by stirring the electromagnetic wave by the electromagnetic stirrer.

Further, in the electromagnetic wave measuring method according to the embodiment, the housing, the first antenna that emits an electromagnetic wave corresponding to the input electric signal, the electric field strength of the electric field are detected, and the voltage corresponding to the detected electric field strength is output. In an electromagnetic wave measuring device including a second antenna, a third antenna that detects the electric field strength of the electric field and outputs a voltage corresponding to the detected electric field strength, and an electromagnetic stirrer that stirs the electromagnetic waves in the housing. The first electromagnetic wave and the third electromagnetic wave are installed in the housing and outside the predetermined effective space in the housing, and the second electromagnetic wave is installed in the effective space in the housing and are effective in a predetermined reference state. It has a first detection procedure (in the example described above, detection procedure D4) in which the object to be measured is arranged in the space, the object to be measured is operated, and the voltage output from the third antenna is detected. As a result, the electromagnetic wave measurement method can reduce the volume occupied by the second antenna among the volumes in the effective space.

Further, in the electromagnetic wave measurement method, an electric field probe (electric field probe PB in the example described above) is placed in the effective space of the reference state, electromagnetic waves are radiated from the first antenna, and the voltage output from the electric field probe is detected. Based on the second detection procedure (detection procedure D1 in the example described above), the electric field strength of the electric field corresponding to the electromagnetic wave radiated to the first antenna, and the voltage detected by the second detection procedure. The first calculation procedure (calculation procedure C1 in the example described above) for calculating the conversion coefficient for converting the electric field strength into voltage, the voltage detected by the first detection procedure, and the conversion calculated by the first calculation procedure. A configuration may be used that further comprises a second calculation procedure (calculation procedure C3 in the example described above) for calculating the radiated power of the object to be measured based on the coefficient.

Further, the electromagnetic wave measurement method is a third detection procedure (in the example described above, in the example described above, the electromagnetic field is radiated from the first antenna and the voltage output from the second antenna is detected when the effective space is in the reference state. The detection procedure D2) and the fourth detection procedure (example described above) in which the object to be measured is placed in the effective space of the reference state, the electromagnetic field is radiated from the first antenna, and the voltage output from the second antenna is detected. Then, based on the detection procedure D3), the electric field strength of the electric field corresponding to the electromagnetic wave radiated to the first antenna, the voltage detected by the third detection procedure, and the voltage detected by the fourth detection procedure. It further has a third calculation procedure (calculation procedure C2 in the example described above) for calculating the correction coefficient for correcting the conversion coefficient, and the second calculation procedure includes the voltage detected by the first detection procedure and the voltage detected by the first detection procedure. A configuration may be used, which is a procedure for calculating the radiated power of the object to be measured based on the conversion coefficient calculated by the first calculation procedure and the correction coefficient calculated by the third calculation procedure.

Further, in the electromagnetic wave measurement method, the configuration in which the third antenna is integrally configured with the first antenna may be used.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and changes, substitutions, deletions, etc., are made as long as the gist of the present invention is not deviated. May be done.

1 ... Electromagnetic wave measuring device, 2 ... Information processing device, 3 ... Receiver device, 11 ... Housing, 12 ... Electromagnetic stirrer, A1 ... 1st antenna, A2 ... 2nd antenna, A3 ... 3rd antenna, C1, C2, C3 ... Calculation procedure, D1, D2, D3, D4 ... Detection procedure, P ... Electronic equipment, PB ... Electric field probe, WV ... Effective space

Claims (11)

1. With the housing
   The first antenna that radiates electromagnetic waves according to the acquired electrical signal,
   A second antenna that detects the electric field strength of the electric field and outputs a voltage corresponding to the detected electric field strength, a third antenna that detects the electric field strength of the electric field and outputs a voltage corresponding to the detected electric field strength, and the housing. An electromagnetic stirrer that stirs the electromagnetic waves in the body,
   With
   The first antenna and the third antenna are installed in the housing and outside a predetermined effective space in the housing.
   The second antenna is installed in the effective space in the housing.
   Electromagnetic wave measuring device.
2. The third antenna is integrally configured with the first antenna.
   The electromagnetic wave measuring device according to claim 1.
3. The antenna factor of the second antenna is equal to or higher than the antenna factor of the third antenna.
   The electromagnetic wave measuring device according to claim 1 or 2.
4. The second antenna and the third antenna have an element.
   The maximum length of the element of the second antenna is equal to or less than the maximum length of the element of the third antenna.
   The electromagnetic wave measuring device according to any one of claims 1 to 3.
5. The second antenna and the third antenna have an opening surface and have an opening surface.
   The maximum length of the opening surface of the second antenna is equal to or less than the maximum length of the opening surface of the third antenna.
   The electromagnetic wave measuring device according to any one of claims 1 to 3.
6. A receiving device connected to the second antenna is provided.
   The noise floor of the receiving device is one-hundredth or more of the permissible value of the radiant power value for the object to be measured that emits electromagnetic waves.
   The electromagnetic wave measuring device according to any one of claims 1 to 5.
7. The effective space is a space in the housing in which the electric field strength becomes uniform due to the agitation of electromagnetic waves by the electromagnetic stirrer.
   The electromagnetic wave measuring device according to any one of claims 1 to 6.
8. The housing, the first antenna that emits electromagnetic waves according to the input electric signal, the second antenna that detects the electric field strength of the electric field and outputs the voltage according to the detected electric field strength, and the electric field strength of the electric field. In an electromagnetic wave measuring device including a third antenna that detects and outputs a voltage corresponding to the detected electric field strength, and an electromagnetic stirrer that stirs the electromagnetic waves in the housing.
   The first antenna and the third antenna are installed in the housing and outside a predetermined effective space in the housing.
   The second antenna is installed in the effective space in the housing.
   It has a first detection procedure in which an object to be measured is placed in the effective space in a predetermined reference state, the object to be measured is operated, and a voltage output from the third antenna is detected.
   Electromagnetic wave measurement method.
9. A second detection procedure in which an electric field probe is placed in the effective space in the reference state, electromagnetic waves are radiated from the first antenna, and a voltage output from the electric field probe is detected.
   The first calculation procedure for calculating the conversion coefficient for converting the electric field strength into a voltage based on the electric field strength of the electric field corresponding to the electromagnetic wave radiated to the first antenna and the voltage detected by the second detection procedure. ,
   A second calculation procedure for calculating the radiant power of the object to be measured based on the voltage detected by the first detection procedure and the conversion coefficient calculated by the first calculation procedure.
   Further have,
   The electromagnetic wave measuring method according to claim 8.
10. A third detection procedure for radiating an electromagnetic wave from the first antenna and detecting a voltage output from the second antenna when the effective space is in the reference state.
    A fourth detection procedure in which the object to be measured is placed in the effective space in the reference state, electromagnetic waves are radiated from the first antenna, and the voltage output from the second antenna is detected.
    The conversion coefficient is corrected based on the electric field strength of the electric field corresponding to the electromagnetic wave radiated to the first antenna, the voltage detected by the third detection procedure, and the voltage detected by the fourth detection procedure. The third calculation procedure for calculating the correction coefficient to be performed, and
    With more
    The second calculation procedure is based on the voltage detected by the first detection procedure, the conversion coefficient calculated by the first calculation procedure, and the correction coefficient calculated by the third calculation procedure. This is the procedure for calculating the radiant power of the object to be measured.
    The electromagnetic wave measuring method according to claim 9.
11. The third antenna is integrally configured with the first antenna.
    The electromagnetic wave measuring method according to any one of claims 8 to 10.

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