Measurement apparatus

Abstract

To provide a measuring device capable of specifying a leakage direction of noise.SOLUTION: A measuring device includes a probe 2 having a loop-shaped electrode terminal which is electromagnetically coupled with an object to be measured and through which an electric signal corresponding to characteristics of an electromagnetic field flows, and two first and second output terminals connected to the electrode terminal. In addition, the measuring device includes an electric field measuring unit that executes a process of extracting an electric field signal based on a first output-signal I1 outputted from the first output-terminal and a second output-signal I2 outputted from the second output-terminal, and a magnetic field measuring unit that executes a process of extracting a magnetic field signal at the same timing as the electric field measuring unit based on the first output-signal and the second output-signal. The measurement device calculates a pointing vector by performing a cross-spectrum operation on the electric field signal and the magnetic field signal extracted at the same timing, and stores data indicating the calculated pointing vector.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosure herein relates to metrology devices. [Background technology]

[0002] Patent Document 1 discloses a device for measuring the intensity of an electromagnetic field emitted as noise from an electrical device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-206163 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need to identify not only the noise intensity (i.e., scalar quantity) but also the direction of noise leakage. However, the measurement device disclosed in Patent Document 1 cannot identify the direction of noise leakage.

[0005] One disclosed object is to provide a measurement device that can identify the direction of noise leakage. [Means for solving the problem]

[0006] The measurement device disclosed herein is a probe (2) having a loop-shaped electrode terminal (221) that is electromagnetically coupled with an object to be measured and configured to pass an electrical signal corresponding to the characteristics of the electromagnetic field emitted from the object to be measured, and a first output terminal (222a) and a second output terminal (222b) connected to the electrode terminal; an electric field measuring unit (10) that executes a process of extracting an electric field signal (Ie) that is a signal component derived from an electric field based on a first output signal (I1) that is an electric signal output from a first output terminal and a second output signal (I2) that is an electric signal output from a second output terminal; a magnetic field measurement unit (11) that executes a process of extracting a magnetic field signal (Im), which is a signal component derived from a magnetic field, based on the first output signal and the second output signal at the same timing as the electric field measurement unit; a vector calculation unit (12) that calculates a Poynting vector by performing a cross-spectrum calculation on the electric field signal and the magnetic field signal extracted at the same timing by the electric field measurement unit and the magnetic field measurement unit, respectively; and a data storage unit (13) that stores data indicating the Poynting vector calculated by the vector calculation unit in a memory.

[0007] According to the disclosed measurement positions, the Poynting vector is calculated by cross-spectral calculation of the electric field signal and the magnetic field signal acquired at the same time. The electric field signal used to calculate the Poynting vector corresponds to the electric field vector of the noise, and the magnetic field signal corresponds to the magnetic field vector of the noise. Therefore, the Poynting vector calculated here represents the direction of noise leakage. In other words, according to the above configuration, it is possible to identify the direction of noise leakage. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a measurement device. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 2 is a block diagram showing the configuration of a control unit. [Figure 5] FIG. [Figure 6] FIG. 10 is a conceptual diagram showing calculations performed by a control unit. [Figure 7] FIG. 10 is a diagram showing a probe according to a modified example. [Figure 8] FIG. 10 is a diagram showing a probe according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the following description, components having the same function may be given the same reference numerals, and a detailed description thereof may be omitted. Also, components having the same function may be given the same or similar names, and a detailed description thereof may be omitted. When only a portion of the configuration is mentioned, the description given elsewhere may apply to the other portions.

[0010] In the present disclosure, "parallel" does not necessarily mean a completely parallel state. A state tilted by several degrees to approximately 20 degrees from a completely parallel state may also be considered parallel. In other words, "parallel" may include a substantially parallel state. Similarly, the term "orthogonal" in the present disclosure does not necessarily mean a completely orthogonal state.

[0011] First Embodiment First, a schematic configuration of the measurement device 100 will be described with reference to Fig. 1. The measurement device 100 is used to measure the electromagnetic field (noise) distribution of a measurement object T. The measurement device 100 acquires the electromagnetic field distribution by measuring the electromagnetic field at multiple measurement points. The electromagnetic field distribution is used, for example, to identify the source of noise in the measurement object T.

[0012] The object to be measured T may be a variety of items that operate using electricity, such as an electronic device. In this embodiment, the object to be measured T has a substrate, as shown in FIG. 1 . The object to be measured T has the substrate, electronic components, and a conductor pattern that connects the electronic components. The object to be measured T is put into an operating state during measurement by the measurement device 100. Then, the electromagnetic field formed by the electromagnetic waves radiated while the object to be measured T is in operation is measured.

[0013] In this disclosure, the concept of a right-handed three-dimensional coordinate system having mutually orthogonal X-, Y-, and Z-axes is introduced for explanation. As shown in Fig. 1, the X- and Y-axes are defined along the substrate direction of the object to be measured T. The Z-axis is defined along the thickness direction of the substrate of the object to be measured T.

[0014] <Measuring equipment> The measuring device 100 includes a control unit 1, a probe 2, and a moving device. It is sufficient for the measuring device 100 to include the control unit 1 and the probe 2, and the moving device is not an essential component.

[0015] <probe> The probe 2 is a measuring instrument that is electromagnetically coupled with the object to be measured T and configured to generate an electrical signal corresponding to the characteristics of the electromagnetic field emitted from the object to be measured T. The probe 2 has a loop-shaped electrode terminal (loop portion 221 described later) and two output terminals, a first output terminal 222a and a second output terminal 222b, connected to the electrode terminal.

[0016] The probe 2 and the control unit 1 are connected by coaxial cables 31 and 32. A first output signal I1 output from the first output terminal 222a and a second output signal I2 output from the second output terminal 222b are transmitted to the control unit 1 by the coaxial cables 31 and 32. Connectors (not shown) are provided at the ends of the coaxial cables 31 and 32.

[0017] The probe 2 is configured such that its tip is placed close to the object T to be measured, thereby outputting a signal corresponding to the noise generation state from the first output terminal 222a and the second output terminal 222b. The probe 2 may be configured to be movable relative to the object T to be measured. The probe 2 is placed at multiple measurement points to measure the distribution of the electromagnetic field. The position of the probe 2 relative to the object T to be measured may be changed by any method. In this embodiment, the position of the probe 2 is sequentially moved from one measurement point to another by a moving device. The moving device may be a robot arm or the like. Note that the position of the probe 2 may be changed manually. Furthermore, instead of changing the position of the probe 2 relative to the object T to be measured, the position of the object T to be measured may be changed relative to the fixed probe 2. The moving device may be a device that changes the position of the object T to be measured, such as a belt conveyor.

[0018] The probe 2 has a plate-like configuration that is long in one direction (here, the Z-axis direction). For convenience, the plate thickness direction of the probe 2 is also referred to as the front direction here. Figure 2 is a front view of the probe 2 in this embodiment. As shown in Figure 2, the probe 2 has a generally T-shaped planar shape. The probe 2 has a base 20 and an extension 21. The base 20 and the extension 21 are each a rectangular plate-like member. The extension 21 is formed to be longer than the base 20, and the longitudinal direction of the extension 21 corresponds to the Z-axis direction mentioned above. The base 20 is arranged at the upper end of the extension 21, oriented laterally relative to the extension 21.

[0019] Five holes 23 are provided on the left and right sides of the base 20. The left-right direction is the longitudinal direction of the base 20. The holes 23 are used to connect to coaxial cables. Specifically, of the five holes 23, the central center hole 230 is connected to the central conductors of the coaxial cables 31 and 32. The surrounding four holes are configured to fix the outer conductor of the connector (and therefore the coaxial cable) to the base 20 for electrical connection. The number of the four surrounding holes may be changed. The coaxial cable and the base 20 may be fixed by any method that ensures electrical conductivity, such as solder, screws, or bolts. For convenience, in this disclosure, the center hole 230 on the left side of the base 20 may also be referred to as the first center hole 230a, and the center hole 230 on the right side of the base 20 may also be referred to as the second center hole 230b.

[0020] The midpoint between the first central hole 230a and the second central hole 230b, i.e., the center of the base 20 in the longitudinal direction, is also referred to as the base center 20c below. The extension 21 can also be interpreted as a member extending from the base center 20c. The direction in which the extension 21 extends as viewed from the base 20 is referred to as the downward direction. The lowermost edge of the extension 21 is also referred to as the lowermost end 2L. Note that if the extension 21 is viewed as the main body of the probe 2, the base 20 can also be interpreted as a region at the upper end of the extension 21 that has a portion protruding in the width direction.

[0021] The probe 2 has a multi-layer structure. The first layer is a metal layer. The metal layer is the outermost layer of the probe 2 and provides an electromagnetic shielding function. The first metal layer may also serve to increase mechanical strength. In Figure 2, the area where the first layer exists is indicated by hatching with a dot pattern. The second layer is a dielectric layer that provides electrical insulation and has a specific dielectric constant. The third layer is a layer on which the conductor pattern 220 is formed. The conductor pattern 220 forms a transmission path for an electrical signal in response to noise. The fourth layer is a dielectric layer and has the same function as the second layer. The conductor pattern 220 of the third layer may be formed on either the fourth layer or the second layer, which are facing each other. The fifth layer is a metal layer and, as the outermost layer of the probe 2, has the same function as the first layer. The second and fourth layers correspond to resin layers that insulate the conductor pattern 220 from the metal layers of the first and fifth layers.

[0022] FIG. 3 shows an example of the shape of the conductor pattern 220. The conductor pattern 220 is formed so as to connect from the first central hole 230a through the lower end of the extension portion 21 to the second central hole 230b. That is, the conductor pattern 220 has a first output terminal 222a connected to the first central hole 230a and a second output terminal 222b connected to the second central hole 230b. The conductor pattern 220 has initial sections extending a predetermined length from each of the first output terminal 222a and the second output terminal 222b toward the vicinity of the base center 20c. The conductor pattern 220 further has a section extending downward from the vicinity of the base center 20c of the initial section. The conductor pattern 220 forms a loop portion 221 at the lower end of the extension portion 21. The loop portion 221 has a bilaterally symmetrical shape. The loop portion 221 forms a rectangular loop. In the present disclosure, one side of the loop portion 221 that extends parallel to the bottom end 2L is referred to as the loop lower side 221L.

[0023] The first and fifth metal layers are not provided within a predetermined distance from the bottom end 2L so that the lower portion of the loop portion 221 (i.e., the loop lower portion 221u) is exposed to electromagnetic waves as noise. The portion of the extension portion 21 where the first and fifth metal layers are not provided is referred to as the exposed portion 21b. The exposed portion 21b may be set as a portion of the extension portion 21 up to a predetermined distance (e.g., 5 mm or 10 mm) above the bottom end 2L. The exposed portion 21b may be less than half of the loop portion 221. In other embodiments, the exposed portion 21b may be configured so that the entire loop portion 221 is exposed to electromagnetic waves. Here, exposure to electromagnetic waves refers to a state in which the loop portion 221 is not covered with a metal body that blocks electromagnetic waves and can receive electromagnetic waves as noise.

[0024] In exposed portion 21b, the second and fourth dielectric layers are the outermost layers. That is, in exposed portion 21b, loop lower portion 221u is not covered by the first and fifth metal layers. Loop lower portion 221u refers to the portion of loop portion 221 that exists within exposed portion 21b. With this structure, when exposed portion 21b of probe 2 is brought close to object to be measured T, magnetic field coupling is possible between current flowing through object to be measured T and loop lower portion 221u. Furthermore, electric field coupling is possible between current flowing through object to be measured T and loop lower side 221L.

[0025] When a current flowing through the object to be measured T is magnetically coupled to the loop lower part 221u, a current (hereinafter referred to as a magnetic field component current) flows through the loop part 221. When a current flowing through the object to be measured T is electric field coupled to the loop lower part 221L, a current (hereinafter referred to as an electric field component current) flows through the loop part 221. The current flowing from the loop part 221 to the first output terminal 222a and the second output terminal 222b is a composite current of the electric field component current and the magnetic field component current. A composite current (first output signal I1) obtained by adding the magnetic field component current and the electric field component current is outputted to the first output terminal 222a. A composite current (second output signal I2) obtained by subtracting the magnetic field component current from the electric field component current is outputted to the second output terminal 222b.

[0026] The electric field component currents flowing from the loop section 221 to the first output terminal 222a and the second output terminal 222b are in phase with each other, while the magnetic field component currents are out of phase with each other. That is, if the magnetic field component current is Ih and the electric field component current is Ie, then I1 = Ie + Im and I2 = Ie - Im. From this relationship, the electric field component current and the magnetic field component current can be calculated. For example, the electric field component current can be extracted by adding the first output signal I1 and the second output signal I2 and dividing the result by 2. The magnetic field component current can also be extracted by subtracting the second output signal I2 from the first output signal I1 and dividing the result by 2. By calculating the electric field component current and the magnetic field component current, the electric field strength and the magnetic field strength can be calculated. For convenience, the electric field component and the magnetic field component are described here as being measured using current, but the electric field and the magnetic field may also be measured using voltage or power. The term "current" may be replaced with "voltage" or "power."

[0027] Hereinafter, the axis that passes through the center of the loop lower portion 221u and is perpendicular to the plate surface of the extension portion 21 will be referred to as the detection axis Ax. The direction of the detection axis Ax is the direction in which the magnetic field is measured at a certain measurement point. The measurement direction of the electric field is the positive direction of the Z axis. The measurement direction of the Poynting vector is a direction rotated 90 degrees with respect to the detection axis Ax.

[0028] In addition, a plurality of through-hole vias (not shown) are provided in the outer peripheral portion of the probe 2 excluding the exposed portion 21b. The through-hole vias are so-called through vias that provide electrical continuity between the first and fifth layers. The through-hole vias are provided around the outer periphery of the probe 2 so as to follow the outer periphery of the probe 2. The spacing between the through-hole vias may be set to a value sufficiently small compared to the wavelength of the noise to be measured. Each through-hole via may be connected to an adjacent through-hole via. The through-hole vias formed in the outer peripheral portion excluding the exposed portion 21b provide a shielding function that prevents noise components from being superimposed from the side on the conductive pattern 220 other than the exposed portion.

[0029] <Movement Device> The moving device is a device that moves the probe 2 in response to a signal from the control unit 1 so that the probe 2 is positioned at a predetermined measurement point. The moving device is connected to the control unit 1. The moving device changes the position of the probe 2 in response to a control signal input from the control unit 1. The moving device is configured to be able to move the probe 2 in the X-axis, Y-axis, and Z-axis directions shown in FIG. 1. The moving device is configured to be able to rotate the orientation of the probe 2 around the Z-axis at the measurement point. The moving device rotates the probe 2 in response to a signal from the control unit 1 so that the probe 2 faces the measurement direction. In other words, the moving device rotates the probe 2 so that the direction of the detection axis Ax faces the measurement direction. The moving device moves the bottom end 2L of the probe 2 from one measurement point to another in sequence. The bottom end 2L of the probe 2 is the tip of the probe 2.

[0030] <Control unit> The control unit 1 is a device that calculates the electromagnetic field radiated from the object to be measured T based on the electrical signal obtained via the probe 2. The control unit 1 may include a computer equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and input / output (IO) ports. As shown in FIG. 4, the control unit 1 includes an electric field measurement unit 10, a magnetic field measurement unit 11, a vector calculation unit 12, a data storage unit 13, a correction value storage unit 14, a display unit 15, and a movement control unit 16. All or part of these components, except for the display unit 15, may be realized by the computer constituting the control unit 1 executing a program. The control unit 1 includes a mixer, an oscillator, an A / D converter, and a Fourier transform unit.

[0031] The movement control unit 16 is a component that controls the moving device so that the probe 2 is positioned at a predetermined measurement point. The measurement points may be set arbitrarily. For example, the measurement points may be arranged at predetermined intervals in the X-axis and Y-axis directions. In other words, the measurement points may be arranged in a matrix. Measurement settings such as the position, number, and spacing of the measurement points may be set in advance or may be input by the user of the measuring device 100. The movement control unit 16 also controls the measurement direction at the measurement point. The movement control unit 16 transmits a signal indicating the measurement point and measurement direction to the moving device. Note that the probe is configured to be fixed at one measurement point for a predetermined time. This enables the control unit 1 to acquire time-series data indicating the transition of the electric field and magnetic field over a certain period of time for one measurement point.

[0032] The movement control unit 16 may control the movement device to move the probe 2 parallel to the upper surface of the substrate of the measurement target T. For example, the movement control unit 16 may control the probe 2 to move sequentially to each measurement point on an XY plane parallel to the upper surface of the substrate. As an example, the movement control unit 16 may control the probe 2 to move linearly from one measurement point to the next measurement point along the X axis or Y axis.

[0033] The movement control unit 16 may rotate the probe 2 at each measurement point. The movement control unit 16 rotates the probe 2 based on the Z axis, which is a direction perpendicular to the XY plane parallel to the upper surface of the substrate. In this embodiment, the movement control unit 16 controls the detection axis Ax at the measurement point so as to orient it in a predetermined first direction (for example, the X axis direction). After measurement in the first direction is completed, the movement control unit 16 controls the detection axis Ax so as to orient it in a second direction different from the first direction. The first direction and the second direction may be arbitrary directions. The second direction may be a direction perpendicular to the first direction (for example, the Y axis direction).

[0034] The electric field measurement unit 10 is a component that measures the electric field at a measurement point. The electric field measurement unit 10 executes a process of extracting an electric field signal, which is a signal component derived from the electric field, based on the first output signal I1 and the second output signal I2. The electric field measurement unit 10 is configured to execute a process of correcting the phase of the extracted electric field signal using an electric field correction value stored in the correction value storage unit 14.

[0035] The magnetic field measuring unit 11 is a component that measures the magnetic field at a measurement point. The magnetic field measuring unit 11 executes a process of extracting a magnetic field signal, which is a signal component derived from a magnetic field, based on the first output signal I1 and the second output signal I2, at the same timing as the electric field measuring unit 10. The magnetic field measuring unit 11 is configured to execute a process of correcting the phase of the extracted magnetic field signal using a magnetic field correction value stored in the correction value storage unit 14.

[0036] The vector calculation unit 12 is a component that calculates the Poynting vector. The vector calculation unit 12 calculates the Poynting vector by performing a cross-spectrum operation on the electric field signal and the magnetic field signal extracted at the same timing by the electric field measurement unit 10 and the magnetic field measurement unit 11, respectively.

[0037] The vector calculation unit 12 calculates a Poynting vector for one measurement point based on the electric field signal and the magnetic field signal when the detection axis Ax is oriented in a first direction, and also calculates a Poynting vector based on the electric field signal and the magnetic field signal when the detection axis Ax is oriented in a second direction. Hereinafter, a Poynting vector calculated based on the electric field signal and the magnetic field signal measured at a specific measurement point when the detection axis Ax of the probe 2 is oriented in a first direction will also be referred to as a first Poynting vector. Furthermore, a Poynting vector calculated at the same measurement point based on the electric field signal and the magnetic field signal measured when the detection axis Ax of the probe 2 is oriented in a second direction will also be referred to as a second Poynting vector. The vector calculation unit 12 calculates a composite Poynting vector by combining the first Poynting vector and the second Poynting vector.

[0038] The data storage unit 13 is a component that stores data indicating the pointing vector calculated by the vector calculation unit 12 in a predetermined memory. The memory may be any storage medium. In this embodiment, the memory is a volatile memory such as a RAM. The memory may also be a non-volatile memory such as a flash memory. The data storage unit 13 is configured to store data indicating the pointing vector in association with a measurement point. Specifically, the data of the pointing vector calculated at a certain measurement point is stored in association with position information (coordinates) indicating the measurement point. The data storage unit 13 stores data indicating the composite pointing vector in association with a predetermined measurement point.

[0039] The data storage unit 13 acquires a shape image of the object to be measured T. The shape image is an image that shows the outer shape of the object to be measured T. The shape image may be an image obtained by photographing the object to be measured T, or may be an illustration such as a diagram or sketch showing the shape of the object to be measured T. The shape image may be stored in ROM in advance. In that case, the data storage unit 13 may acquire the shape image from the ROM. The data storage unit 13 may acquire the shape image from any device other than the control unit 1.

[0040] The data storage unit 13 creates output data by superimposing an element image P indicating the direction of the calculated pointing vector on the shape image. The element image P may be an arrow or a line indicating the flow of the vector. The output data may be still image data or animation data.

[0041] The data storage unit 13 may create output data by superimposing an element image P indicating the real part of the calculated pointing vector on a shape image.The data storage unit 13 may create output data by superimposing an element image P indicating the imaginary part of the calculated pointing vector on a shape image.

[0042] The data storage unit 13 may change the display mode of the element image P to be superimposed on the shape image according to the magnitude of the calculated pointing vector value. If the element image P is an arrow, the length, size, color, or thickness of the arrow may be changed. For example, the display mode of the element image P may be changed so that the arrow becomes thicker as the pointing vector value increases. If the output data is animation data, the speed and frequency of blinking or color change of the element image P may be changed according to the magnitude of the pointing vector. For example, the display mode of the element image P may be changed so that the arrow blinks faster as the pointing vector value increases.

[0043] The correction value storage unit 14 stores electric field correction values ​​and magnetic field correction values, which are values ​​for correcting the phase of the electric field signal. The electric field correction values ​​and magnetic field correction values ​​are calculated in advance by electromagnetic field simulation. The electric field correction values ​​and magnetic field correction values ​​may be determined based on the gap between the results of the electromagnetic field simulation and the results of actual measurement.

[0044] In the electromagnetic field simulation, the electric field and magnetic field transmission characteristics at a specific measurement point on the evaluation board without the probe 2 are calculated. The evaluation board is a board used for calculating phase correction. A board with only one wiring, such as a microstrip line, is preferable. The electric field and magnetic field transmission characteristics refer to the amplitude and phase changes of the electric field and magnetic field when power is applied to the wiring on the evaluation board, and may also be interpreted as propagation characteristics or noise radiation characteristics. The actual measurement results refer to the detection results of the electric field and magnetic field measured by placing the probe 2 close to the point on the evaluation board where the phase amplitude characteristics of the electromagnetic field simulation were calculated. The actual measurement results reflect the transmission characteristics from the evaluation board to the first output terminal 222a or the second output terminal 222b of the probe 2, so they may differ from the simulation results. The actual measurement results may be interpreted as the electric field and magnetic field transmission characteristics of the evaluation board with the probe 2 installed. The difference in transmission characteristics between with and without the probe 2 is calculated as the electric field correction value and the magnetic field correction value.

[0045] The display unit 15 is a device that displays data acquired from the data storage unit 13. The display unit 15 is, for example, a liquid crystal display. The display unit 15 acquires data indicating a pointing vector from the data storage unit 13 and displays the magnitude and direction of the pointing vector. FIG. 5 is an example of an image displayed on the display unit 15 based on the output data. In FIG. 5, the pointing vector is represented by an arrow. Note that for ease of illustration, all arrows in FIG. 5 are represented in black, but in an actual displayed image, each arrow may have a different color depending on its intensity. For example, the color of the arrow may be set to be closer to red for higher intensity and closer to blue for lower intensity. Here, the intensity may be interpreted as the magnitude of the pointing vector.

[0046] <Calculating the Poynting Vector> The electric field and magnetic field are expressed as the following equations (1) and (2).

number

number

[0047]

number

number

[0048] <Processing flow> The processing flow performed by the control unit 1 will be described (see FIG. 6). The movement control unit 16 controls the movement of the probe 2 to at least two measurement points in order to acquire the electromagnetic field distribution. The movement control unit 16 first sends a signal to the movement device to move the probe 2 to the first measurement point. The movement control unit 16 then sends a signal to the movement device so that the detection axis Ax faces in the first direction at the first measurement point. The measurement directions, such as the first direction and the second direction, may be any direction in a plane parallel to the substrate of the object to be measured T (i.e., the XY plane).

[0049] When the probe 2 is placed at a first measurement point and the detection axis Ax is oriented in a first direction, the electric field measurement unit 10 performs a process of extracting an electric field signal. The magnetic field measurement unit 11 performs a process of extracting a magnetic field signal at the same timing as the electric field measurement unit 10. Specifically, the first output signal I1 and the second output signal I2 are each multiplied in a mixer by a reference signal for frequency conversion generated by an oscillator. As a result, the first output signal I1 and the second output signal I2 are down-converted. Note that measurement of the first output signal I1 and the second output signal I2 at one measurement point may continue for a predetermined time.

[0050] The down-converted first output signal I1 and second output signal I2 are each converted into digital data by an A / D converter at the same timing. "Same timing" means that the A / D converters sample at the same timing. In other words, the first output signal I1 and second output signal I2 are sampled using the same clock.

[0051] The electric field measurement unit 10 extracts an electric field component current by adding the first output signal I1 and the second output signal I2 converted into digital data by the A / D conversion unit. The magnetic field measurement unit 11 obtains a magnetic field component current by subtracting the down-converted first output signal I1 and the second output signal I2. The electric field measurement unit 10 extracts the electric field strength from the electric field component current as an electric field signal. The magnetic field measurement unit 11 extracts the magnetic field strength from the magnetic field component current as a magnetic field signal at the same timing as the electric field measurement unit 10. The electric field measurement unit 10 and the magnetic field measurement unit 11 operate on the same clock and perform sampling synchronously. Therefore, the timing at which the electric field measurement unit 10 samples the electric field signal (e.g., intensity) coincides with the timing at which the magnetic field measurement unit 11 samples the magnetic field signal. The timing here may be referred to as a sampling point, time, bin, etc.

[0052] The electric field measurement unit 10 performs a Fourier transform on the electric field signal. At this time, the electric field measurement unit 10 performs a process of correcting the phase of the extracted electric field signal using the electric field correction value stored in the correction value storage unit 14. The magnetic field measurement unit 11 performs a Fourier transform on the magnetic field signal. At this time, the magnetic field measurement unit 11 performs a process of correcting the phase of the extracted magnetic field signal using the magnetic field correction value stored in the correction value storage unit 14.

[0053] The vector calculation unit 12 calculates a Poynting vector (first Poynting vector) by performing cross-spectral calculation on the corrected electric field signal and the corrected magnetic field signal. The data storage unit 13 stores the first Poynting vector in memory in association with the first measurement point and the first direction.

[0054] Next, the movement control unit 16 transmits a signal to the movement device to orient the detection axis Ax in the second direction at the first measurement point. Then, similarly, the electric field measurement unit 10 performs a process to extract an electric field signal, and the magnetic field measurement unit 11 performs a process to extract a magnetic field signal at the same timing as the electric field measurement unit 10. The electric field measurement unit 10 similarly performs a process to correct the phase of the electric field signal. The magnetic field measurement unit 11 similarly performs a process to correct the phase of the magnetic field signal. The vector calculation unit 12 performs a cross-spectral calculation on the corrected electric field signal and the corrected magnetic field signal to calculate a Poynting vector (second Poynting vector).

[0055] The vector calculation unit 12 calculates a resultant pointing vector by combining the first pointing vector and the second pointing vector. The data storage unit 13 stores data indicating the calculated resultant pointing vector in association with the first measurement point.

[0056] A resultant Poynting vector is calculated for the second measurement point in the same manner. The data storage unit 13 stores data indicating the calculated resultant Poynting vector in association with the second measurement point.

[0057] <Summary of the embodiment> In this embodiment, the Poynting vector is calculated by cross-spectral calculation of the electric field signal and the magnetic field signal acquired at the same time. The electric field signal used to calculate the Poynting vector corresponds to the electric field vector of the noise, and the magnetic field signal corresponds to the magnetic field vector of the noise. Therefore, the Poynting vector calculated here represents the direction of noise leakage. In other words, with the above configuration, it is possible to identify the direction of noise leakage.

[0058] In this embodiment, a composite Poynting vector is calculated by combining the first Poynting vector and the second Poynting vector. The first Poynting vector and the second Poynting vector are Poynting vectors observed when the detection axis Ax is oriented in different directions. That is, the first Poynting vector and the second Poynting vector conceptually correspond to data measuring the Poynting vector of noise from two perspectives. Therefore, the composite Poynting vector obtained by combining the first Poynting vector and the second Poynting vector can more accurately represent the original Poynting vector of the noise than either the first Poynting vector or the second Poynting vector alone. In this way, by calculating the composite Poynting vector by combining the first Poynting vector and the second Poynting vector, the noise radiation direction in a plane parallel to the substrate of the measurement object T can be measured more accurately.

[0059] In this embodiment, the probe 2 is placed and used in sequence at a first measurement point and a second measurement point that are at different positions relative to the object T to be measured. Then, data indicating the pointing vector at the first measurement point and data indicating the pointing vector at the second measurement point are associated with the respective positions and saved. This makes it possible to obtain pointing vectors at two locations. In other words, it becomes possible to confirm the noise occurrence status (noise distribution) at two locations. By observing the noise occurrence status at at least two points, it may be possible to estimate the overall noise distribution trend.

[0060] Of course, as mentioned above, the number of measurement points is not limited to two, and may be set to three or more. For example, the measurement points may be arranged in a matrix with 1 cm intervals. A configuration in which the measurement points are arranged two-dimensionally may enable the noise distribution to be identified in a planar manner. Furthermore, by increasing the density of the measurement points, in other words, by reducing the intervals between the measurement points, it may be possible to evaluate the noise distribution characteristics more precisely.

[0061] The extracted electric field signal may have a phase difference with respect to the original electric field signal due to the shape of the probe 2, particularly the shape of the loop portion 221, the distance between the loop portion 221 and the object to be measured T, etc. Therefore, by performing a process of correcting the phase of the electric field signal as in this embodiment, it is possible to obtain a more accurate Poynting vector.

[0062] Similarly, the extracted magnetic field signal may have a phase difference with respect to the original magnetic field signal due to factors such as the shape of the probe 2. Therefore, by performing a phase correction process on the magnetic field signal as in this embodiment, it is possible to obtain a more accurate Poynting vector. That is, according to the configuration in which the electric field signal and the magnetic field signal are corrected and used as described above, it is possible to reduce the influence of measurement errors resulting from the placement of the probe 2 near the object T to be measured.

[0063] In this embodiment, output data is created by superimposing an element image P indicating the direction of the Poynting vector on a shape image. This makes it easier for developers to understand the direction of noise leakage. Note that the developer may be replaced by an inspector.

[0064] In this embodiment, an element image P indicating the real part of the Poynting vector is superimposed on a shape image, which makes it easier for the developer to understand the actual flow of noise in the object T to be measured.

[0065] In this embodiment, the display mode of the element image P superimposed on the shape image is changed depending on the magnitude of the value of the pointing vector, which makes it easier for the developer to check areas that are heavily affected by noise.

[0066] The system is equipped with a display unit 15 that acquires data indicating the pointing vector from the data storage unit 13 and displays the magnitude and direction of the pointing vector. This allows the developer to check the magnitude and direction of the calculated pointing vector on the display unit 15 in real time.

[0067] <Modification> The shape of the loop portion 221 may be any other shape. The loop portion 221 may be any polygonal shape or may be circular. The loop portion 221 may have an asymmetrical shape. The probe 2 may have a pen-shaped or cylindrical housing as a whole. The substrate on which the conductive pattern 220 is formed, such as the extension portion 21 and the base portion 20, may be housed in the housing. In this case, the housing may have a shielding function for insulating the portions of the conductive pattern 220 other than the loop portion 221 from noise. For example, the tip of the housing corresponding to the loop lower portion 221u may be made of resin, and the portion above it may be made of metal.

[0068] The probe 2 may have a spacer for keeping the distance D (see FIG. 1) between the loop lower side 221L and the object to be measured T constant. For example, resin may be further added to the tip of the probe 2, below the loop lower side 221L. The spacer may be a resin member such as a cap attached to the bottom end 2L. In these cases, measurement may be performed while the bottom end 2L of the probe 2 is in contact with the plate surface of the object to be measured T. Alternatively, the moving device may have a member as a spacer for keeping the distance D constant.

[0069] The process of correction using the electric field correction value and the magnetic field correction value may be any element. The process of correction using the electric field correction value and the magnetic field correction value does not have to be performed. Furthermore, correction may be performed using only either the electric field correction value or the magnetic field correction value. Accordingly, the correction value storage unit 14 may be configured to store only either the electric field correction value or the magnetic field correction value.

[0070] The control unit 1 does not necessarily have to include the display unit 15. Data indicating the pointing vector may be output to a device other than the measurement device, and the measurement results may be displayed via the other device. The control unit 1 may be configured to store a data set indicating the pointing vector for each measurement point in a removable recording medium (for example, a USB memory or an SD card).

[0071] The first output signal I1 and the second output signal I2 are sampled using the same clock, but they do not necessarily have to be the same clock. The first output signal I1 and the second output signal I2 may be sampled using different clocks. In this case, the Poynting vector can be calculated by correcting for the difference in clocks.

[0072] The data storage unit 13 may create output data in which an element image P indicating the imaginary part of the calculated pointing vector is superimposed on the shape image.

[0073] The probe 2 may be configured as a handheld probe device integrated with the control unit 1. The handheld probe device has a grip part for an inspector to hold in his / her hand, and the probe 2 may be configured to protrude from the upper end of the grip part. A screen for the display unit 15 may be provided at the upper end of the grip part. The screen may display the direction and magnitude of the pointing vector using an arrow or the like. The handheld probe device allows developers to measure noise propagation paths more easily.

[0074] Second Embodiment The configuration (shape, etc.) of the probe 2 can be changed to various configurations other than those described above. For example, it may be a configuration as shown in FIG. 7. In this embodiment, the object to be measured T is a wire harness. The probe 2 has a hollow cylindrical magnetic core 25 through which the wire harness is passed, and a conductor element 24 having a loop portion 240 as an electrode terminal. As in the first embodiment, the probe 2 has two output terminals, a first output terminal and a second output terminal (both not shown), connected to the loop portion 240.

[0075] The magnetic core 25 functions to concentrate the magnetic field. The magnetic core 25 is arranged so as to interlink with the loop portion 240. As shown in FIG. 7, a wire harness is passed through the inner diameter portion of the magnetic core 25. The inner diameter of the magnetic core 25 is larger than the diameter of the wire harness. With the wire harness passed through the inner diameter portion of the magnetic core 25, the probe 2 is movable parallel to the direction in which the wire harness extends.

[0076] The loop portion 240 is attached to the magnetic core 25 in a chain-like manner. The loop portion 240 includes a facing portion 241 and a lead-out portion 242. The facing portion 241 is a portion fixed to the inner surface of the magnetic core 25. The lead-out portion 242 is a portion extending radially from the end of the facing portion 241 so as to fit along the end face 251 of the magnetic core 25. The facing portion 241 is shaped to fit along the inner diameter of the magnetic core 25. The facing portion 241 is formed so as to face the wire harness when the wire harness is passed through the inner diameter portion of the magnetic core 25. The circumferential length (also referred to as width) of the facing portion 241 is set to be larger than the width of the lead-out portion 242. For example, if the width of the lead-out portion 242 is approximately 1 cm, the width of the facing portion 241 may be set to a value more than twice as large, such as 4 cm. By increasing the width of the facing portion 241, the facing portion 241 can be more easily capacitively coupled to the wire harness, and the strength of the electric field component signal can be increased.

[0077] In this embodiment, the wire harness is configured to pass through the inner diameter portion of the magnetic core 25. Since the facing portion 241 of the loop portion 240 is attached to the inner surface of the magnetic core 25, the fluctuation range of the distance between the facing portion 241 and the wire harness is kept below a certain value determined by subtracting the diameter of the wire harness from the inner diameter of the magnetic core 25. This makes it possible to keep the fluctuation in the distance between the probe 2 and the object to be measured T below a certain value when a user performs measurement using the probe 2.

[0078] In this embodiment, the facing portion 241 is formed to face the wire harness when the wire harness is passed through the inner diameter portion of the magnetic core 25. This facilitates capacitive coupling between the facing portion 241 and the wire harness. This can result in a more accurate electric field signal extracted by the electric field measurement unit 10. This allows for a more accurate measurement of the Poynting vector.

[0079] Third Embodiment The probe 2 may have a configuration as shown in FIG. 8. In this embodiment, the probe 2 has two conductor patterns 220 and 320. The extension portion 21 in this embodiment is cylindrical. In FIG. 8, the extension portion 21 is represented by a dashed line. As in the first embodiment, the conductor pattern 220 forms a loop portion 221 at the lower end of the extension portion 21. The conductor pattern 320 forms a loop portion 321 at the lower end of the extension portion 21. The loop portion 321 may have the same basic function and configuration as the loop portion 221, except that it is oriented in a different direction. Hereinafter, the loop portion 221 will be referred to as the first loop portion 221. Hereinafter, the loop portion 321 will be referred to as the second loop portion 321. Like the first loop portion 221, the second loop portion 321 corresponds to an electrode terminal.

[0080] The probe 2 has two output terminals, namely, a third output terminal and a fourth output terminal, connected to the second loop portion 321, in addition to the first output terminal 222a and the second output terminal 222b connected to the first loop portion 221. A third output signal I3 output from the third output terminal and a fourth output signal I4 output from the fourth output terminal are transmitted to the control unit 1 via a coaxial cable (not shown).

[0081] The first loop portion 221 forms a first loop surface Ea. The first loop surface Ea is a plane including the inner region of the first loop portion 221. The second loop portion 321 forms a second loop surface Eb. The second loop surface Eb is a plane including the inner region of the second loop portion 321. The first loop surface Ea and the second loop surface Eb face in different directions. The first loop surface Ea and the second loop surface Eb intersect with each other. In this modified example, the first loop surface Ea and the second loop surface Eb are perpendicular to each other.

[0082] Hereinafter, the loop lower portion 221u will be referred to as the first loop lower portion 221u. The detection axis Ax of the first loop portion 221 will be referred to as the first detection axis Ax. The first detection axis Ax is perpendicular to the first loop plane Ea. Of the second loop portion 321, the portion provided on the exposed portion 21b will be referred to as the second loop lower portion 321u. The first loop portion 221 and the second loop portion 321 are designed so that the center points cn of the first loop lower portion 221u and the second loop lower portion 321u are at approximately the same position.

[0083] An axis passing through the center of the second loop lower portion 321u and perpendicular to the second loop plane Eb is referred to as the second detection axis Bx. The direction of the second detection axis Bx is the direction in which the electromagnetic field is measured at a certain measurement point. The first detection axis Ax and the second detection axis Bx are axes that face in different directions with respect to the longitudinal direction (e.g., the Z axis) of the extension portion 21. In this modification, the first loop plane Ea and the second loop plane Eb are perpendicular to each other, and therefore the detection axis Ax and the second detection axis Bx are perpendicular to each other.

[0084] In this embodiment, the first detection axis Ax and the second detection axis Bx are oriented in different directions. As a result, the measurement direction of the first loop portion 221 and the measurement direction of the second loop portion 321 are different directions. Therefore, by using the probe 2 in this embodiment, it is possible to simultaneously measure electric fields and magnetic fields in two different directions in a single measurement. This improves the accuracy of Poynting vector calculation in a single measurement. [Explanation of symbols]

[0085] 10 electric field measurement unit, 11 magnetic field measurement unit, 12 vector calculation unit, 13 data storage unit, 14 correction value memory unit, 15 display unit, 2 probe, 221 electrode terminal, 222a first output terminal, 222b second output terminal, 24 conductor element, 241 opposing portion, 25 magnetic core, I1 first output signal, I2 second output signal, Ie electric field signal, Im magnetic field signal.

Claims

1. a probe (2) having a loop-shaped electrode terminal (221) that is electromagnetically coupled to an object to be measured and configured to allow an electrical signal corresponding to the characteristics of the electromagnetic field emitted from the object to be measured to flow, and a first output terminal (222a) and a second output terminal (222b) connected to the electrode terminal; an electric field measuring unit (10) that executes a process of extracting an electric field signal (Ie) that is a signal component derived from an electric field based on a first output signal (I1) that is an electric signal output from the first output terminal and a second output signal (I2) that is an electric signal output from the second output terminal; a magnetic field measurement unit (11) that executes a process of extracting a magnetic field signal (Im), which is a signal component derived from a magnetic field, based on the first output signal and the second output signal at the same timing as the electric field measurement unit; a vector calculation unit (12) that calculates a Poynting vector by performing a cross-spectrum calculation on the electric field signal and the magnetic field signal extracted at the same timing by the electric field measurement unit and the magnetic field measurement unit, respectively; a data storage unit (13) that stores data indicating the Poynting vector calculated by the vector calculation unit in a memory.

2. the object to be measured has a substrate, The vector calculation unit calculating the Poynting vector as a first Poynting vector based on the electric field signal and the magnetic field signal extracted when the detection axis of the probe is oriented in a first direction parallel to the substrate at a predetermined measurement point; calculating the Poynting vector as a second Poynting vector based on the electric field signal and the magnetic field signal extracted when the detection axis of the probe is parallel to the substrate and is oriented in a second direction different from the first direction at the predetermined measurement point; calculating a composite pointing vector by combining the calculated first pointing vector and the calculated second pointing vector; The measurement device according to claim 1 , wherein the data storage unit stores data indicating the calculated resultant Poynting vector in association with the predetermined measurement point.

3. A measurement device in which the probe is placed and used in sequence at a first measurement point and a second measurement point that are different positions relative to the object to be measured, The vector calculation unit calculating the Poynting vector at the first measurement point based on the electric field signal and the magnetic field signal extracted at the first measurement point; calculating the Poynting vector at the second measurement point based on the electric field signal and the magnetic field signal extracted at the second measurement point; 3. The measurement device according to claim 1, wherein the data storage unit is configured to store data indicating the calculated pointing vector at the first measurement point and data indicating the calculated pointing vector at the second measurement point in association with their respective positions.

4. a correction value storage unit (14) in which an electric field correction value, which is a value for correcting the phase of the electric field signal, is stored; 3. The measurement device according to claim 1, wherein the electric field measurement unit is configured to perform a process of correcting the phase of the extracted electric field signal using the electric field correction value stored in the correction value storage unit.

5. a correction value storage unit (14) in which a magnetic field correction value, which is a value for correcting the phase of the magnetic field signal, is stored; 3. The measurement device according to claim 1, wherein the magnetic field measurement unit is configured to perform a process of correcting the phase of the extracted magnetic field signal using the magnetic field correction value stored in the correction value storage unit.

6. The data storage unit data indicating the calculated pointing vector is stored in association with position information of the measurement point; acquiring a shape image of the object to be measured; The measurement device according to claim 2 , wherein output data is generated by superimposing an element image indicating the direction of the calculated pointing vector on the shape image.

7. The data storage unit data indicating the calculated pointing vector is stored in association with position information of the measurement point; acquiring a shape image of the object to be measured; 3. The measurement device according to claim 2, wherein output data is created by superimposing an element image corresponding to the real part of the calculated Poynting vector on the shape image.

8. The measurement device according to claim 6 , wherein the data storage unit changes a display mode of the element image to be superimposed on the shape image in accordance with the magnitude of the calculated value of the pointing vector.

9. 3. The measurement device according to claim 1, further comprising a display unit (15) that acquires data indicating the Poynting vector from the data storage unit and displays the magnitude and direction of the Poynting vector.

10. the object to be measured is a wire harness, The probe is a hollow cylindrical magnetic core (25) through which the wire harness is passed; a conductor element (24) having a loop portion as the electrode terminal, the magnetic core is arranged to interlink with the loop portion and has an inner diameter larger than that of the wire harness, 3. The measuring device according to claim 1, wherein the loop portion has a facing portion (241) that is fixed to the inner surface of the magnetic core.

Images