JP5418424B2 - Electromagnetic field probe - Google Patents

Description

  The present invention relates to an electromagnetic field probe.

  In order to measure an electromagnetic field (near electromagnetic field) generated near the surface of a printed circuit board or the like, an electromagnetic field probe using a metal probe electrode or a loop coil is used. These electromagnetic field probes can detect an electromagnetic field with excellent high frequency characteristics of, for example, 1 gigahertz or more.

  As an electric field probe for detecting a near electric field, an electric field is detected by processing a probe electrode and a shield ground around the probe electrode and detecting a voltage induced in the probe electrode by a measurement electric field. For example, there is one that uses a core wire of a cut surface of a semi-rigid coaxial cable as a probe electrode. Further, in order to detect the signal induced in the probe electrode with high efficiency, an amplifier with high input impedance may be provided near the probe tip. In order to improve the sensitivity of such an electric field probe, it is preferable that the core wire protrudes slightly from the surrounding shield ground at the tip of the electric field probe. On the other hand, in this case, there is a problem of degradation of spatial resolution.

  If the electric field probe is structured so that the core wire does not protrude at the tip, a spatial resolution of the size of the inner diameter of the tip of the shield ground can be obtained. Therefore, in the electric field probe using the cut surface of the semi-rigid coaxial cable, the spatial resolution can be improved by using a probe having a small outer conductor diameter as well as the inner core wire diameter. In addition, when the tip of the probe is made thin with the surrounding ground conductor, the spatial resolution is improved (see Patent Document 1).

  On the other hand, as a magnetic field probe for measuring a near magnetic field, a magnetic field probe in which a loop coil is formed at the tip of a semi-rigid coaxial cable, a magnetic field probe in which a loop coil is formed by wiring on a printed board, and the like are known (Patent Document 2). , 3). In order to reduce the sensitivity of the magnetic field probe to the electric field, a shielded loop structure in which an electric field shield structure is added to the loop coil is used. In the electric field shield structure covering the loop coil, a part of the shield structure is cut in order to prevent the magnetic field from being shielded by the eddy current induced in the shield structure. For example, by forming a loop with a shield conductor that covers the core wire by bending the end of the coaxial cable, and cutting a part of the loop of the shield conductor, or a shield dead where a part of the loop of the signal line is exposed from the shield conductor A loop structure is known (see Non-Patent Document 1). Also known is a sealed dead loop structure formed of a printed circuit board pattern (see Patent Document 4). There has also been proposed a structure in which the entire probe comprising a loop coil and a transmission line for transmitting the signal is integrally covered with a shield conductor having an opening on the tip coil side (see Patent Document 5).

  A method of detecting a magnetic field from differential signal components of two signal lines at both ends of a loop coil is known (see Non-Patent Document 1 and Patent Document 6). As a method for detecting both an electric field and a magnetic field by a single probe, a method is also known in which a magnetic field is detected from differential signal components of two signal lines at both ends of a loop coil, and an electric field is detected from an added signal component (non-existing). (See Patent Document 1 and Patent Documents 6 and 7).

Japanese Patent Laid-Open No. 5-264672 JP 62-106379 A JP-A-8-129058 Japanese Patent Laid-Open No. 10-82845 JP 2000-214200 A Japanese Patent Laid-Open No. 10-268209 JP 2000-206163 A

John D. Dyson, Measurement of Near Fields of Antennas and Scatterers, IEEE Transactions on Antennas and Propagation, Vol. AP-21, No. 4, PP. 446-460, July 1973

  As described above, for example, in the electric field probe, the spatial resolution of the electric field probe can be improved by reducing the diameter of the coaxial cable, or by forming the probe electrode at the tip of the probe and the shield ground around it. However, on the other hand, the measurement sensitivity is lowered, and the sensitivity is significantly lowered unless the probe tip is sufficiently close to the measurement object. Therefore, particularly in the case of a measurement object with unevenness on which electronic components are mounted, scanning measurement along the unevenness is required, and it takes a long time, and it is not possible to quickly find the location where electromagnetic noise is generated.

  In order to avoid this difficulty, first find out where the electromagnetic noise is generated using an electric field probe with low spatial resolution but high sensitivity, and then use the electric field probe with high spatial resolution to find details of the area where electromagnetic noise occurs. It is possible to examine the method. However, in this case, it is necessary to replace the electric field probe with the scanning measurement apparatus, and in particular, it is often necessary to calibrate a positional deviation or the like when the electric field probe having a high spatial resolution is mounted, which is complicated and takes time. In addition, a method in which a highly sensitive electric field probe and a high spatial resolution electric field probe are installed adjacent to each other is also conceivable. However, in this case, it is necessary to correct the displacement of the measurement positions of the two electric field probes, which causes a problem that the measurement electric field is disturbed by the electric field probe having a high spatial resolution at the time of measurement by the high sensitivity electric field probe.

  The present invention has been made in view of the above-described problems. With a simple single probe configuration, both detailed electromagnetic field detection with high spatial resolution and electromagnetic field detection with a high sensitivity and a wide detection range can be performed simultaneously. Another object of the present invention is to provide an electromagnetic field probe that can be appropriately performed and is excellent in convenience for realizing desired electromagnetic field detection easily in a short time.

  In one aspect of the electromagnetic field probe, one end is an electromagnetic field detection unit, and a first signal line extending from the detection unit and an insulator along the extending direction of the first signal line are provided. A first transmission line having a first grounding conductor formed therebetween, and a common current blocking mechanism provided in the first transmission line, for blocking an output of a common current of the first transmission line, A second transmission line having a second signal line extending at one end connected to a portion between the detection portion of the first ground conductor and the common current interrupting mechanism, The other end of the signal line is a first output unit, and the other end of the second signal line is a second output unit.

  In another aspect of the electromagnetic field probe, one end is an electromagnetic field detection unit, and a first signal line extending from the detection unit and an insulator along the extending direction of the first signal line are provided. A first transmission line having a first grounding conductor formed therebetween, a second transmission line having a second signal line, one end of the first transmission line and the second signal line, And a common current cutoff mechanism that cuts off the output of the common current of the first transmission line, the other end of the first signal line is a first output unit, and the second output The other end of the signal line is a second output unit.

  According to each aspect described above, a simple single probe configuration enables both high-resolution and detailed electromagnetic field detection and high-sensitivity and wide detection range electromagnetic field detection simultaneously or appropriately. Thus, it is possible to realize an electromagnetic field probe excellent in convenience and capable of detecting an intended electromagnetic field easily in a short time.

It is a schematic diagram which shows schematically the structure of the electromagnetic field probe by 1st Embodiment. It is a schematic sectional drawing which shows the partial cross section structure of the electromagnetic field probe by 1st Embodiment. It is a schematic diagram which shows one structure of the electromagnetic field detection system provided with the electromagnetic field probe by 1st Embodiment. It is a schematic diagram which shows the electromagnetic field detection method using the electromagnetic field detection system provided with the electromagnetic field probe by 1st Embodiment. It is a characteristic view which shows the measurement result of the electric field profile on the microstrip line of wiring width 50micrometer measured by the electromagnetic field probe by 1st Embodiment. It is a schematic diagram which shows schematically the structure of the electromagnetic field probe by the modification 1 of 1st Embodiment. It is a schematic sectional drawing which shows the manufacturing process of the probe main body of the electromagnetic field probe by the modification 1 of 1st Embodiment. It is a schematic sectional drawing which shows the partial cross section structure of the electromagnetic field probe by the modification 1 of 1st Embodiment. It is a schematic diagram which shows schematically the structure of the electromagnetic field probe by the modification 2 of 1st Embodiment. It is a schematic diagram which shows roughly the structure of the electromagnetic field probe by 2nd Embodiment. It is a schematic diagram which shows roughly the structure of the electromagnetic field probe by 3rd Embodiment. It is a schematic diagram which shows partially another example of a loop coil. It is a schematic diagram which shows schematically the structure of the electromagnetic field probe by the modification 1 of 3rd Embodiment. It is a schematic diagram which shows roughly the structure of the electromagnetic field probe by the modification 2 of 3rd Embodiment. It is a schematic sectional drawing which shows the partial cross section structure of the electromagnetic field probe by the modification 2 of 3rd Embodiment. It is a schematic diagram which shows partially another example of a loop coil. It is a schematic diagram which shows schematically the structure of the electromagnetic field probe by the modification 3 of 3rd Embodiment. It is a schematic sectional drawing which shows the manufacturing process of the probe main body of the electromagnetic field probe by the modification 3 of 3rd Embodiment. It is a schematic diagram which shows roughly the structure of the electromagnetic field probe by the modification 4 of 3rd Embodiment. It is a schematic diagram for demonstrating the measurement principle of the electric field and magnetic field by the electromagnetic field probe by the modification 4 of 3rd Embodiment. It is a schematic diagram which shows the structure which has arrange | positioned the switch of probe output. It is a schematic diagram which shows the other structure which has arrange | positioned the switch of a probe output.

  Hereinafter, embodiments of the electromagnetic field probe will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram schematically showing the configuration of the electromagnetic field probe according to the first embodiment.
The electromagnetic field probe includes a first transmission line 1, a second transmission line 2, an adjustment mechanism 3, a common current blocking mechanism 4, and a ground (ground) conductor 5. As will be described later, in this electromagnetic field probe, a near-field electric field detector is provided at the tip of the first transmission line 1, and the first transmission line 1 has a low sensitivity but a high spatial resolution first probe output. Do. On the other hand, the second transmission line 2 performs a high-sensitivity second probe output although the spatial resolution is low.

  The first transmission line 1 is formed using a coaxial cable (semi-rigid cable). As shown in FIG. 2A, the first signal line 1a, the first insulator 1b, and the first transmission line 1 are formed. A ground conductor 1c is provided. In the first transmission line 1, the portion of the first signal line 1 a exposed at the tip surface of the first transmission line 1 is used as a near electric field detection unit 1 </ b> A. An electrode serving as the first output unit 1B is provided in a portion extending from the rear end surface of the first transmission line 1 of the first signal line 1a, and the first probe output is performed from the electrode. . Here, the spatial resolution of the first probe output can be further improved by narrowing and narrowing the shape of the tip of the first transmission line 1.

  The first signal line 1a is a core-shaped inner conductor line, and is made of a conductive material such as copper (Cu). The first insulator 1b covers the surface (side surface) of the first signal line 1a and is made of an insulating material such as polytetrafluoroethylene (PTFE). The first ground conductor 1c is made of a conductive material such as Cu, for example, covers the surface (side surface) of the first insulator 1b, and electromagnetically shields the first signal line 1a.

Similar to the first transmission line 1, the second transmission line 2 is formed using a coaxial cable, and has a second signal line 2a, a second insulator 2b, and a second ground conductor 2c. Configured.
In the second transmission line 2, the tip portion of the second signal line 2a extends from the tip surface of the second transmission line 2 by a predetermined length, and the adjustment mechanism 3 and the common current blocking mechanism 4 on the surface of the first ground conductor 1c. The front end portion is electrically connected to a predetermined portion between them, for example, a connection portion 1d by solder or the like. Instead of this electrical connection, a capacitor may be used for capacitive connection, for example. An electrode to be the second output portion 2A is provided at the rear end of the second signal line 2a extending from the rear end surface of the second transmission line 2, and the second probe output is performed from the electrode. .

  The second signal line 2a is a core-shaped inner conductor line, and is made of a conductive material such as Cu, for example. The second insulator 2b covers the surface (side surface) of the second signal line 2a and is made of an insulating material such as PTFE. The second ground conductor 2c is made of a conductive material such as Cu, for example, covers the surface (side surface) of the second insulator 2b, and electromagnetically shields the second signal line 2a.

The adjusting mechanism 3 is formed by using, for example, a coaxial cable in which the core wire is removed from a coaxial cable whose diameter is substantially equal to the diameter of the first transmission line 1. As shown in FIG. 2B, the adjustment mechanism 3 is configured to include a third insulator 3a and a third ground conductor 3b, and is inserted into the first transmission line 1 at a predetermined portion. Fixed. As a result, the tip portion including the detection portion 1A of the first transmission line 1 protrudes from the adjustment mechanism 3. By adjusting the length of the protruding portion 1C of the first transmission line 1, the electric field sensitivity and spatial resolution of the second probe output of the second transmission line 2 can be controlled. If the length of the protruding portion 1C is sufficiently shorter than the propagation wavelength of the electromagnetic field to be measured, the frequency characteristics of the output from the second output unit 2A can be improved.
Further, when the characteristic impedance of the first transmission line 1 with respect to the adjustment mechanism 3 is matched with the characteristic impedance of the second transmission line 2, the second probe becomes longer when the third ground conductor 3 c of the adjustment mechanism 3 is lengthened. The frequency characteristics of the output can be kept good.

  When the adjusting mechanism 3 is not provided, the electric field sensitivity and space of the second probe output of the second transmission line 2 are adjusted by adjusting the installation position of the common current blocking mechanism 4 in the first transmission line 1. The resolution can be appropriately controlled. At this time, it is possible to adjust the speed of decrease in sensitivity when the distance from the measurement target (for example, wiring) is increased. Further, if the length from the installation position of the common current cutoff mechanism 4 to the detection unit 1A of the first transmission line 1 is sufficiently shorter than the propagation wavelength of the electromagnetic field to be measured, the frequency characteristic of the second probe output. Can be improved.

  The common current interruption mechanism 4 is a magnetic body, for example, a ferrite bead, and a through hole 4 a having a diameter substantially equal to the diameter of the first transmission line 1 is formed. The common current interrupting mechanism 4 is inserted into the first transmission line 1 and fixed at a predetermined part between the connection part 1d of the second signal line 2a and the output part 1B in the first transmission line 1. The common current cut-off mechanism 4 cuts off a later-described common current flowing through the first transmission line 1. The first probe output has almost no common current in its output component. The common current is guided from the connection site 1d to the second transmission line 2 immediately before being cut off by the common current cut-off mechanism 4, and becomes an output component of the second probe output.

  The ground conductor 5 has a conductive plate such as Cu, for example. The ground conductor 5 is electrically connected to the surface of the third ground conductor 3b of the adjusting mechanism 3 by solder or the like at each end 5a of the conductive plate. The ground conductor 5 is connected to the surface of the first ground conductor 1c of the first transmission line 1 and the surface of the second ground conductor 2c of the second transmission line 2 by solder or the like. Thereby, the first ground conductor 1c, the second ground conductor 2c, the third ground conductor 3b, and the ground conductor 5 are electrically connected. The common current cutoff mechanism 4 is held in a non-contact state with the ground conductor 5 in the opening 5 b of the ground conductor 5.

The electromagnetic field probe of FIG. 1 of the present embodiment is manufactured as follows, for example.
As described above, semi-rigid cables are used as the first and second transmission lines 1 and 2. Ferrite beads are used as the magnetic material of the common current blocking portion. As the third ground conductor, a semi-rigid cable core wire having a core wire diameter equal to the outer diameter of the first transmission line is used.

First, the semi-rigid cable used as the first and second transmission lines 1 and 2 is cut to an appropriate length.
Next, the printed board on which one side of the copper plate or copper foil is attached is cut into the shape of the ground conductor 5, and the rear end side of the semi-rigid cable that becomes the first transmission line 1 is soldered to the ground conductor 5.
Next, for example, ferrite beads are inserted from the detection unit 1 </ b> A of the first transmission line 1, and are bonded and fixed to predetermined positions of the first transmission line 1 to form the common current blocking mechanism 4.

Next, the core wire at the tip of the semi-rigid cable to be the second transmission line 2 is exposed. The semi-rigid cable is appropriately bent and soldered to the ground conductor 5. Further, the exposed core wire of the semi-rigid cable is soldered to the connection portion 1d of the first ground conductor 1c.
Next, the adjusting mechanism 3 is inserted from the tip of the first transmission line 1 and soldered to the end 5 a of the ground conductor 5.
If necessary, an SMA (Sub Miniature type A) connector or the like is connected to the first and second probe output sides of the semi-rigid cable used as the first and second transmission lines 1 and 2.
Thereafter, the cut surface on the distal end side of the first transmission line 1 is polished to form the detection unit 1A, and an electromagnetic field probe is formed.

In the electromagnetic probe configured as described above, the first probe output with low sensitivity but high spatial resolution, and the second probe output with high sensitivity but low spatial resolution of the second transmission line 2 are as follows. Can be obtained simultaneously.
When the near electric field is detected by the detector 1A, the total current flowing through the first signal line 1a of the first transmission line 1 is I1, the current flowing through the first ground conductor 1c is I2, and the common current Ic and the difference The dynamic current Id is defined as follows.
Ic≡I1 + I2
Id≡I1-I2
I1 and I2 can be expressed as a combined current of the component of Ic and the component of Id as in the following formula. The common current is also called a common mode current.
I1 = (Ic + Id) / 2
I2 = (Ic−Id) / 2

The common current blocking mechanism 4 arranged in the first transmission line 1 transmits the differential current component to the output unit 1B and simultaneously blocks transmission of the common current to the output unit 1B.
The differential current component flowing through the first transmission line 1 is almost zero outside the first transmission line 1 because the total current is zero in the first signal line 1a and the first ground line 1c along the first signal line 1a. Does not generate a magnetic field. Therefore, transmission is possible regardless of the presence or absence of the common current blocking mechanism 4 made of a magnetic material. On the other hand, the common current component generates a large magnetic field outside the first transmission line 1 because the total current is not zero. Thereby, the magnetic material of the common current blocking mechanism 4 is magnetized by the common current component to generate a large impedance, and a current flows through the second transmission line 2 having a small impedance.

The current flowing through the first signal line 1a of the first transmission line 1 that has passed through the common current blocking mechanism 4 is output from the output unit 1B as the first probe output. The diameter of the first signal line 1a, which is an internal core wire, is small, and the exposed area of the first signal line 1a on the tip surface of the first transmission line 1 is small. For this reason, the first probe output is obtained as an output with low sensitivity but high spatial resolution.
On the other hand, the current flowing through the second signal line 2a, which is interrupted by the common current interrupting mechanism 4 and guided to the second transmission line 2, is output from the output unit 2A as the second probe output. Not only the first signal line 1a of the first transmission line 1 but also the first ground conductor 1c functions as an electric field sensor. Therefore, the second probe output is obtained as a highly sensitive output with low spatial resolution.

Hereinafter, an electromagnetic field detection method using the electromagnetic field probe configured as described above will be described.
FIG. 3 is a schematic diagram showing a configuration of an electromagnetic field detection system including the electromagnetic field probe according to the first embodiment. FIG. 4 is a schematic diagram showing an electromagnetic field detection method using this electromagnetic field detection system.

  In the electromagnetic field detection system of FIG. 3, reference numeral 101 denotes a probe stage on which the electromagnetic field probe 10 according to the present embodiment is installed. The probe stage 101 is provided with a mechanism for appropriately rotating the electromagnetic field probe 10 around the central axis (in the direction of arrow R). Reference numeral 102 denotes a probe moving mechanism that can move the probe stage 101 in the direction of the arrow X, the direction of the arrow Y, and the direction of the arrow X. Reference numeral 103 denotes a stage controller that controls driving of the probe moving mechanism 102. Reference numeral 104 denotes a measuring instrument such as a spectrum analyzer that measures and displays the electromagnetic field distribution detected by the electromagnetic field probe 10. The first output unit 1B of the electromagnetic field probe 10 is connected to the input terminal 104a of the measuring device 104, and the second output unit 2A is connected to the input terminal 104b of the measuring device 104. Reference numeral 105 denotes an observation device such as a CCD camera for observing an image of scanning the wiring or the like by the probe moving mechanism 102. Reference numeral 106 denotes a control device such as a personal computer that performs overall control of the probe stage 101, the probe moving mechanism 102, the stage controller 103, the measuring device 104, and the observation device 105.

A predetermined low noise amplifier may be connected between the first and second output units 1B and 2A of the electromagnetic field probe 10 and the measuring device 104. Thereby, measurement sensitivity can be improved.
Further, a high input impedance amplifier may be connected between the first and second output units 1B and 2A of the electromagnetic field probe 10 and the measuring device 104. Thereby, measurement sensitivity can be improved. In this case, in order to enable high-frequency measurement, it is desirable to make the electromagnetic field probe as small as possible so that the first and second transmission lines in the electromagnetic field probe are shortened. Therefore, it is preferable to produce an electromagnetic field probe in a structure incorporating a high input impedance amplifier.

  Using this electromagnetic field detection system, as shown in FIG. 4, the electric field detection test of the printed circuit board 100 on which the wiring is formed, that is, the electric field radiated from the wiring 107 formed on the printed circuit board 100 is detected.

  The observation device 105 observes the wiring 107 to be an electric field detection target on the printed circuit board 100. The image signal generated by the observation device 105 is transmitted to the control device 106 and appropriately displayed on the display unit of the control device 106. The stage controller 103 drives the probe moving mechanism 102 in accordance with a stage control signal from the control device 106. As a result, the electromagnetic field probe 10 installed on the probe stage 101 scans the printed circuit board 100 in a non-contact state while maintaining a predetermined distance from the wiring 107 to be detected. The scanning direction is a direction intersecting with the longitudinal direction of the wiring 107, for example, a direction orthogonal to the longitudinal direction of the wiring 107 (indicated by an arrow A in FIG. 4). Measurement signals generated based on the electric field distribution detected by the electric field sensing probe 10 are transmitted from the first and second output units 1B and 2A to the input terminals 104a and 104b of the measuring device 104. The measuring device 104 performs, for example, spectrum analysis of the electromagnetic field distribution detected based on the measurement signal in accordance with an instruction from the control device 106.

In the present embodiment, high-sensitivity electric field detection is performed by the second probe output from the second output unit 2A, and a wide range of measurement is performed on the wiring to be measured.
On the other hand, electric field detection with high spatial resolution is performed by the first probe output from the first output unit 1B, and detailed measurement is performed.

  The above-described electromagnetic field detection system can be similarly applied to electromagnetic field probes according to various modifications of the present embodiment, the second embodiment, the third embodiment, and the various modifications described later.

FIG. 5 is a characteristic diagram showing a measurement result of an electric field profile on a microstrip line having a wiring width of 50 μm, measured by the electromagnetic field probe according to the present embodiment. (A) is a line profile, and (b) is a standardized line profile level.
A semi-rigid cable having an outer conductor diameter of 0.33 mm was used as the first transmission line 1, and the diameter of the first signal line 1a was 0.08 mm. The outer diameter of the adjustment mechanism 3 was 0.86 mm, the length was 10 mm, and the length of the protruding portion 1C of the first transmission line 1 was 5 mm. Ferrite beads were used as the magnetic material of the common current interruption mechanism 4.

  A 1 GHz, +10 dBm sine wave signal was input to the wiring, and the probe tip height Z from the wiring was 25 μm, and the first and second probe outputs were measured. From this measurement result, it can be seen that the first probe output has low sensitivity but high spatial resolution, and the second probe output has low spatial resolution but high sensitivity. In addition, it can be seen that the second probe output is less sensitive than the first probe output even if it is far from the wiring.

Table 1 summarizes the results of measuring the spatial resolution and sensitivity of the same electromagnetic field probe as in FIG. 5 while changing the height Z of the probe tip from the wiring.
Spatial resolution is defined as the half width at a position 6 dB lower than the peak output of the line profile measured on the wiring having a width of 50 μm. The sensitivity was measured by measuring the transmittance S21 with a network analyzer using the wiring input as an input and the probe output as an output. The used wiring has a width of 400 μm, a characteristic impedance of 50Ω, and the wiring output is terminated by 50Ω. In Table 1, the value of the measurement result at a frequency of 1 GHz is shown. It can be seen that the second probe output has higher sensitivity than the first probe output, and the sensitivity is less decreased even if the second probe output is away from the wiring.

  As described above, according to the present embodiment, a simple single probe configuration (detection unit is only 1A), a detailed electric field detection (first probe output) with high spatial resolution, and a detection range with high sensitivity. Thus, it is possible to perform both the wide electric field detection (second probe output) simultaneously or appropriately, and an electromagnetic field probe excellent in convenience that can easily perform an intended electric field detection in a short time is realized.

-Modification-
Hereinafter, various modifications of the electromagnetic field probe according to the first embodiment will be described. Components and the like corresponding to the electromagnetic field probe according to the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

(Modification 1)
FIG. 6 is a schematic diagram schematically showing the configuration of the electromagnetic field probe according to the first modification of the first embodiment.
In this example, an electromagnetic field probe having the same operation and effect as the electromagnetic field probe according to the first embodiment is disclosed. Here, the first and second transmission lines 1 and 2, the adjustment mechanism 3, and the ground conductor 5 are formed of a printed circuit board to produce an electromagnetic field probe.

The configuration of the electromagnetic field probe of this example will be described together with its manufacturing method.
In this example, a printed board including three conductive layers is cut into a predetermined shape, and the printed board pattern of the first and second transmission lines 1 and 2 and the ground conductor 5 is formed as shown in FIG. Integrally formed. This printed circuit board pattern is called a probe main body 11.

The probe body 11 is formed as follows, for example.
As shown in FIG. 7A, a prepreg, which is a molding intermediate material in which a carbon fiber is impregnated with a resin (for example, a glass epoxy resin), is sandwiched between copper foils and heated and pressed. Thereby, a double-sided substrate in which the copper foil 11a is adhered to both surfaces of the insulating layer 11b is produced.
Next, a film is laminated on the copper foil 11a of the double-sided substrate to form a resist film, and the mask pattern is exposed and developed to form a resist pattern. The copper foil 11a is etched using this resist pattern. Thereby, as shown in FIG. 7B, a wiring pattern 11c is formed on the insulating layer 11b.

Next, the prepreg and the copper foil are stacked on the insulating layer 11b on which the wiring pattern 11c is formed, and heated and pressed. As a result, as shown in FIG. 7C, a printed circuit board is formed in which the wiring pattern 11c is sandwiched between the copper foils 11a and 11e via the insulating layers 11b and 11d.
This printed circuit board is cut into the shape shown in FIG. In the probe body 11, in the first transmission line 1, the first signal line 1a is the wiring pattern 11c, the first insulator 1b is the insulating layers 11b and 11d, and the first ground conductor 1c is the copper foil 11a, 11e. In the second transmission line 2, the second signal line 2a corresponds to the wiring pattern 11c, the second insulator 2b corresponds to the insulating layers 11b and 11d, and the second ground conductor 2c corresponds to the copper foils 11a and 11e. The ground conductor 5 corresponds to the copper foils 11a and 11e.

  Here, in order to produce a printed circuit board having a larger number of layers, a plurality of wiring patterns are formed, stacked via a prepreg, and formed by heat pressing. Through-hole or via connection is used for interlayer connection for conductively connecting wiring patterns between different layers. The through hole is formed by forming a conductor layer on the inner wall surface and the surface of the hole by plating after opening with a drill. Interlayer connection is used to connect the first and second transmission lines formed on the inner layer of the ground conductor to the electrodes of the output section. Further, by connecting the ground conductors on both sides around the first and second transmission lines, the electromagnetic shield of the first and second transmission lines is strengthened.

Next, for example, ferrite beads are inserted into the first transmission line 1 of the probe main body 11 from the detection unit 1 </ b> A, and are bonded and fixed to predetermined positions of the first transmission line 1 to form the common current blocking mechanism 4.
Next, as shown in FIG. 6, the second signal line 2 a exposed at the distal end side of the second transmission line 2 portion of the probe main body 11 and the first signal transmission line 1 portion of the probe main body 11. The copper wire 12 is soldered between the ground conductors 1c. As a result, the second signal line 2a and the first ground conductor 1c are electrically connected.

  Next, this is cut into a predetermined shape using a printed board similar to the above, and a printed board pattern of the adjusting mechanism 3 is formed as shown in FIG. The two printed circuit board patterns are bonded by being sandwiched from both surfaces of the first transmission line 1 portion of the probe main body 11, and each printed circuit board pattern is interlayer-connected to the ground conductor 5 portion of the probe main body 11. FIG. 8 shows a cross section of a portion where the first transmission line 1 is sandwiched and bonded by two printed circuit board patterns from both sides. In FIG. 8, the first transmission line 1 (the wiring pattern 11c is sandwiched between the copper foils 11a and 11e via the insulating layers 11b and 11d), the copper foil 11g via the insulating layer 11f, and the insulating layer 11h. Between the copper foil 11i. In the adjusting mechanism 3, the third insulator 3a corresponds to the insulating layers 11f and 11h, and the third ground conductor 3b corresponds to the copper foils 11g and 11i.

If necessary, an SMA connector or the like is connected to the first and second probe output sides of the first and second transmission lines 1 and 2 of the probe body 11.
Thereafter, the cut surface on the distal end side of the first transmission line 1 is polished to form the detection unit 1A, and an electromagnetic field probe is formed.

  As described above, according to this example, a simple single probe configuration (detection unit is only 1A), high-resolution and detailed electric field detection (first probe output), high sensitivity and detection range. It is possible to appropriately perform both a wide electric field detection (second probe output), and an electromagnetic field probe excellent in convenience using a printed circuit board that can easily perform an intended electric field detection in a short time. .

(Modification 2)
FIG. 9 is a schematic diagram schematically showing the configuration of the electromagnetic field probe according to the second modification of the first embodiment.
In this example, an electromagnetic field probe having the same operation and effect as the electromagnetic field probe according to the first embodiment is disclosed. Here, the common current interruption mechanism 13 is formed by bending the first transmission line 1 into a coil shape (here, semicircular shape) at a predetermined position. In this example, in consideration of obtaining this configuration, the common current blocking mechanism 13, the first and second transmission lines 1 and 2, the adjusting mechanism 3, and the ground conductor 5 are formed of a printed circuit board, and an electromagnetic field is formed. Make a probe.

  In the example of FIG. 9, the common current interruption mechanism 13 is formed in a shape in which one portion of the first transmission line 1 is bent in a semicircular shape. However, a plurality of bendings or a complicated bending may be formed. Is also suitable. Further, an electromagnetic field absorber such as a magnetic body, a resistor, or a dielectric body, and a combination of these may be placed close to the bent portion. Further, the common current interrupting mechanism 13 is installed close to an electromagnetic field absorber such as a magnetic body, a resistor, or a dielectric body and a combination thereof without forming a bend, and more preferably the first transmission. You may install so that the circumference of a line may be surrounded.

The configuration of the electromagnetic field probe of this example will be described together with its manufacturing method.
In this example, a printed circuit board including five conductive layers is used and cut into a predetermined shape. As shown in FIG. 9, the first and second transmission lines 1 and 2, the adjustment mechanism 3, and the common current interruption mechanism 13 and the printed circuit board pattern of the ground conductor 5 are integrally formed. This printed circuit board pattern is called a probe main body 14.

In this example, the wiring pattern 11c shown in FIG. 8 is made of copper foil through the insulating layers 11b and 11d by the same method as the method of creating the printed circuit board pattern described with reference to FIGS. A printed board including five conductive layers sandwiched by 11a and 11e and further sandwiched by copper foils 11i and 11g constituting the adjusting mechanism 3 via insulating layers 11h and 11f is formed.
This printed circuit board is cut into the shape shown in FIG. In the probe main body 14, as in FIG. 7C, in the first transmission line 1, the first signal line 1 a is the wiring pattern 11 c, the first insulator 1 b is the insulating layers 11 b and 11 d, One ground conductor 1c corresponds to the copper foils 11a and 11e. In the second transmission line 2, the second signal line 2a corresponds to the wiring pattern 11c, the second insulator 2b corresponds to the insulating layers 11b and 11d, and the second ground conductor 2c corresponds to the copper foils 11a and 11e. The common current cut-off mechanism 13 is formed in a shape that is bent in a semicircular shape at a predetermined position in a portion corresponding to the first transmission line 1 of the probe main body 11. The ground conductor 5 corresponds to the copper foils 11a and 11e. The adjusting mechanism 3 corresponds to the copper foils 11i and 11g.

  Next, as shown in FIG. 9, the second signal line 2 a exposed at the distal end side of the second transmission line 2 portion of the probe main body 14 and the first signal transmission line 1 portion of the probe main body 14. Are connected to the ground conductor 1c. As a result, the second signal line 2a and the first ground conductor 1c are electrically connected.

  Next, as shown in FIG. 9, the copper foil pattern of the adjusting mechanism 3 is interlayer-connected to the portion of the ground conductor 5.

If necessary, an SMA connector or the like is connected to the first and second probe output sides of the first and second transmission lines 1 and 2 of the probe body 14.
Thereafter, the cut surface on the distal end side of the first transmission line 1 is polished to form the detection unit 1A, and an electromagnetic field probe is formed.

The electromagnetic field probe of this example is suitable for mass production because the common current blocking mechanism 13 is formed as a pattern on a printed board.
In addition, when the common current blocking mechanism is a ferrite bead, a normal ferromagnetic material may not function as a ferromagnetic material at a high frequency of several GHz or more. Will be avoided.
Further, in order to ensure a sufficient function from a low frequency to a high frequency range, it is also preferable that the common current cutoff mechanism is configured in combination with the common current cutoff mechanism 4 of the first modification.

  As described above, according to this example, a simple single probe configuration (detection unit is only 1A), high-resolution and detailed electric field detection (first probe output), high sensitivity and detection range. Electromagnetic field probe with excellent convenience using a printed circuit board that can perform both a wide electric field detection (second probe output) simultaneously or appropriately, and can easily detect the desired electric field in a short time. Is realized.

(Second Embodiment)
This embodiment discloses an electromagnetic field probe that performs first and second probe outputs as in the first embodiment, but is different from the first embodiment in that the configuration of the common current interruption mechanism is different. Components and the like corresponding to the electromagnetic field probe according to the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

FIG. 10 is a schematic diagram schematically showing the configuration of the electromagnetic field probe according to the second embodiment.
This electromagnetic field probe includes a first transmission line 1, a second transmission line 2, an adjustment mechanism 3, a common current blocking mechanism 4, and a ground conductor 5. In this electromagnetic field probe, as in the first embodiment, the first transmission line 1 is provided with a near electric field detector 1A, and the first transmission line 1 has a low sensitivity but a high spatial resolution. Perform probe output. On the other hand, the second transmission line 2 performs a high-sensitivity second probe output although the spatial resolution is low.

  The common current interruption mechanism 4 is a magnetic substance, for example, a ferrite bead, and has a through hole 4 b having a diameter slightly larger than the diameter of the first transmission line 1. The common current interruption mechanism 4 is inserted into the first transmission line 1 and is fixed at a predetermined portion between the adjustment mechanism 3 and the output part 1B of the first transmission line 1.

  In the present embodiment, in the common current interruption mechanism 4, the first transmission line 1 and the second signal line 2 a of the second transmission line 2 are electromagnetically coupled. Specifically, the extended portion of the second signal line 2a extending from the tip of the second transmission line 2 is wound at least once by the common current blocking mechanism 4 through the through-hole 4b. The distal end of the extended portion is connected to the surface of the second ground conductor 2c of the second transmission line 2 by solder or the like. The extension coil forms the pickup coil 21. The pickup coil 21 faces the first transmission line 1 in the through-hole 4 b of the common current blocking mechanism 4 and is electromagnetically coupled to the first transmission line 1.

  Although the differential current flowing through the first transmission line 1 flows as it is without being affected by the common current cut-off mechanism 4, the common current is cut off, and the first probe output has almost no common current in its output component. . On the other hand, the common current is guided to the second transmission line 2 by the electromagnetic induction coupling, and becomes an output component of the second probe output.

  Here, in order to obtain electromagnetic inductive coupling characteristics at a very high frequency, for example, an air-core coil may be formed instead of the magnetic common current blocking mechanism 4. Furthermore, it is also preferable to combine the magnetic common current blocking mechanism 4 and the air-core coil.

  As described above, according to the present embodiment, a simple single probe configuration (detection unit is only 1A), a detailed electric field detection (first probe output) with high spatial resolution, and a detection range with high sensitivity. Thus, it is possible to appropriately perform both of a wide electric field detection (second probe output), and an electromagnetic field probe excellent in convenience that can easily perform an intended electric field detection in a short time is realized.

(Third embodiment)
This embodiment discloses an electromagnetic field probe that performs the first and second probe outputs as in the first embodiment, but differs from the first embodiment in that the detection target is a near electromagnetic field. Components and the like corresponding to the electromagnetic field probe according to the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

FIG. 11 is a schematic diagram schematically showing the configuration of the electromagnetic field probe according to the third embodiment.
This electromagnetic field probe includes a first transmission line 31, a second transmission line 2, an adjustment mechanism 3, a common current interruption mechanism 4, and a ground conductor 5.

  The first transmission line 31 is formed using a coaxial cable (semi-rigid cable), and similarly to FIG. 2 of the first embodiment, the first signal line 31a, the first insulator 31b, and the first transmission line 31 1 ground conductor 31c. In the first transmission line 31, a tip end portion thereof is rounded into a coil shape to form a loop coil 32. The loop coil 32 has a gap 32a that cuts the ground conductor 31c at the tip, and the tip of the first signal line 31a and the tip of the ground conductor 31c are connected to the surface of the first ground conductor 31c by solder or the like. Is done. The gap 32a may be formed leaving the first insulator 31b, or may be reinforced by covering with an insulator such as an adhesive. In the first transmission line 31, an electrode serving as the first output unit 1 </ b> B is provided on the first signal line 31 a extending from the rear end surface of the first transmission line 31.

Another example of the loop coil is shown in FIG.
The loop coil 33 is formed of a conductor rod 33b that is bent in a substantially semicircular shape from the tip 33a to the connection portion with the surface of the first ground conductor 31c.

  In the electromagnetic field probe according to the present embodiment, the loop coil 32 or 33 provided at the distal end portion of the first transmission line 31 is used as a near magnetic field detection unit. The first transmission line 31 performs a first probe output that is a magnetic field output with low sensitivity but high spatial resolution from the first output unit 31A. On the other hand, the second transmission line 2 outputs a second probe output that is a high-sensitivity electric field output with a low spatial resolution from the second output unit 2A.

  As described above, according to this embodiment, a simple single probe configuration (the detection unit is only the gap 32a or 33a), high-resolution and detailed magnetic field detection (first probe output), and high sensitivity. It is possible to perform both electric field detection (second probe output) with a wide detection range at the same time or appropriately, and an electromagnetic field probe excellent in convenience that can easily detect the desired electromagnetic field in a short time. Is realized.

-Modification-
Hereinafter, various modifications of the electromagnetic field probe according to the third embodiment will be described. Components and the like corresponding to the electromagnetic field probe according to the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

(Modification 1)
FIG. 13 is a schematic diagram schematically illustrating the configuration of an electromagnetic field probe according to Modification 1 of the third embodiment.
In this example, an electromagnetic field probe having the same operation and effect as the electromagnetic field probe according to the third embodiment is disclosed. Here, similarly to the electromagnetic field probe according to the first modification of the first embodiment shown in FIGS. 6 and 7, a printed circuit board is used. Here, the first transmission line 31, the second transmission line 2, the adjustment mechanism 3, and the ground conductor 5 are formed of a printed circuit board to produce an electromagnetic field probe.

Also in this example, the printed circuit board pattern in which the first transmission line 31, the second transmission line 2, and the ground conductor 5 are integrally formed is used as the probe main body 11 as in the first modification of the first embodiment.
In the first transmission line 31 of the probe main body 11, a loop coil 32 is formed in a printed circuit board pattern at the tip portion. Specifically, the wiring pattern 11c of FIG. 7C is rounded in a coil shape at the tip portion of the first transmission line 31, and the tip is copper via a through hole or via formed in the insulating layer 11d. It is electrically connected to the foil 11e (corresponding to the ground conductor 5). A gap 32a for preventing eddy current is formed in the ground conductor 31c at a portion corresponding to the tip of the loop coil 32 of the probe body 11.

  If necessary, an SMA connector or the like is connected to the first and second probe output sides of the first and second transmission lines 31 and 2 of the probe body 11 to form an electromagnetic field probe.

  Similarly to the electromagnetic field probe shown in FIG. 9 according to the second modification of the first embodiment, in the configuration of FIG. 13, the common current blocking mechanism 13 may also be formed of a printed circuit board pattern.

  As described above, according to the present example, a simple single probe configuration (the detection unit is only the gap 32a), a detailed magnetic field detection (first probe output) with high spatial resolution, and a detection range with high sensitivity. Electromagnetic sensor with excellent usability using a printed circuit board, which can perform both electric field detection (second probe output) at the same time or at the same time, and can easily detect the desired electromagnetic field in a short time. A field probe is realized.

(Modification 2)
FIG. 14 is a schematic diagram schematically illustrating a configuration of an electromagnetic field probe according to the second modification of the third embodiment.
In this example, the electromagnetic field probe is configured to include a first transmission line 34, a second transmission line 2, an adjustment mechanism 35, a common current interruption mechanism 4, and a ground conductor 5.

  As shown in FIG. 15A, the first transmission line 34 is provided in parallel so that two coaxial cables (semi-rigid cables) are adjacent to each other in the longitudinal direction. . Each of the transmission lines 34A and 34B includes a first signal line 34a, a first insulator 34b, and a first ground conductor 34c. The first signal line 34a is a core-shaped inner conductor line, and is made of a conductive material such as copper (Cu), for example. The first insulator 34b covers the surface (side surface) of the first signal line 34a and is made of an insulating material such as PTFE. The first ground conductor 34c is made of, for example, a conductive material such as Cu, covers the surface (side surface) of the first insulator 34b, and electromagnetically shields the first signal line 34a. The transmission lines 34 </ b> A and 34 </ b> B serve as the first transmission line 34 by connecting the first ground conductors 34 c to each other by solder or the like.

  In the first transmission line 34, the end portions of the transmission lines 34A and 34B are bent in a substantially semicircular shape to form a loop coil 36. The loop coil 36 has a gap 36a that cuts the ground conductor 34c at the tip. In the gap 36a, the connection portions of the first signal lines 34a of the transmission lines 34A and 34B are exposed from the shield structure. In the first transmission line 34, electrodes serving as the first output portions 34C are provided on the first signal lines 34a extending from the respective rear end surfaces of the transmission lines 34A and 34B. A differential signal is output as the first probe output by the first output portions 34C of the transmission lines 34A and 34B.

The adjustment mechanism 35 is formed using, for example, a coaxial cable in which a portion including the core wire is removed in the shape of the first transmission line 34. As shown in FIG. 15B, the adjustment mechanism 35 includes a third insulator 35a and a third ground conductor 35b. The adjustment mechanism 35 is inserted into the first transmission line 34 and is inserted at a predetermined portion. Fixed. Thereby, the tip portion including the loop coil 36 of the first transmission line 34 protrudes from the adjustment mechanism 35. By adjusting the length of the protruding portion 34D of the first transmission line 34, the electric field sensitivity and spatial resolution of the second probe output of the second transmission line 2 can be controlled. If the length of the protruding portion 34D is sufficiently shorter than the propagation wavelength of the electromagnetic field to be measured, the frequency characteristics of the output from the second output unit 2A can be improved.
Further, by matching the characteristic impedance of the first transmission line 34 with respect to the adjustment mechanism 35 with the characteristic impedance of the second transmission line 2, when the adjustment mechanism 35 is lengthened, the frequency characteristic of the second probe output is improved. Can keep.

  When the adjustment mechanism 35 is not provided, the magnetic field sensitivity and space of the second probe output of the second transmission line 2 are adjusted by adjusting the installation position of the common current blocking mechanism 4 in the first transmission line 34. The resolution can be appropriately controlled. At this time, it is possible to adjust the speed of decrease in sensitivity when the distance from the measurement target (for example, wiring) is increased.

  In the first transmission line 34, instead of forming the loop coil 36, as shown in FIG. 16, both ends of a semicircular conductor rod 37c are connected to the ends of the two first signal lines 34a. Thus, the loop coil 37 may be formed.

  As described above, according to this example, with a simple single probe configuration, detailed magnetic field detection (first probe output) with high spatial resolution and electric field detection (second detection with high sensitivity and wide detection range). Therefore, it is possible to appropriately perform both the probe output and the probe output, and it is possible to realize an electromagnetic field probe excellent in convenience and capable of easily detecting an intended electromagnetic field in a short time.

(Modification 3)
FIG. 17 is a schematic diagram schematically illustrating the configuration of an electromagnetic field probe according to Modification 3 of the third embodiment.
In this example, an electromagnetic field probe having the same operation and effect as the electromagnetic field probe according to the second modification of the third embodiment is disclosed. Here, similarly to the electromagnetic field probe according to the first modification of the first embodiment shown in FIGS. 6 and 7, a printed circuit board is used. Here, the first transmission line 34, the second transmission line 2, the adjustment mechanism 3, and the ground conductor 5 are formed of a printed circuit board, and an electromagnetic field probe is manufactured.

Also in this example, the printed circuit board pattern in which the first transmission line 34, the second transmission line 2, and the ground conductor 5 are integrally formed is used as the probe body 11, as in the first modification of the third embodiment.
The probe body 11 is formed as follows, for example.
First, in the same manner as in FIG. 7A, a double-sided substrate in which the copper foil 11a is adhered to both surfaces of the insulating layer 11b is produced.
Next, a film is laminated on the copper foil 11a of the double-sided substrate to form a resist film, and the mask pattern is exposed and developed to form a resist pattern. The copper foil 11a is etched using this resist pattern. Thereby, a pair of wiring patterns 11c ₁ and 11c ₂ are formed in parallel in the longitudinal direction on the insulating layer 11b.

Next, a prepreg and a copper foil are overlaid on the insulating layer 11b on which the wiring patterns 11c ₁ and 11c ₂ are formed, and heat-pressed. As a result, as shown in FIG. 18A, a printed circuit board is formed in which the wiring patterns 11c ₁ and 11c ₂ are sandwiched between the copper foils 11a and 11e via the insulating layers 11b and 11d.
This printed board is cut into the shape shown in FIG. In the probe body 11, in the first transmission line 34, the first signal lines 34a of the transmission lines 34A and 34B are connected to the wiring patterns 11c ₁ and 11c ₂ , the first insulator 1b is connected to the insulating layers 11b and 11d, One ground conductor 1c corresponds to the copper foils 11a and 11e. In the second transmission line 2, the second signal line 2a corresponds to the wiring pattern 11c, the second insulator 2b corresponds to the insulating layers 11b and 11d, and the second ground conductor 2c corresponds to the copper foils 11a and 11e. The ground conductor 5 corresponds to the copper foils 11a and 11e.

In the first transmission line 34 of the probe main body 11, a loop coil 36 is formed with wiring patterns 11 c ₁ and 11 c ₂ at the tip portion thereof. Specifically, the wiring patterns 11c ₁ and 11c ₂ are rounded into a coil shape at the tip portion of the first transmission line 34, and the tips are connected to each other to form a loop coil. A gap 36 a that prevents eddy current is formed in the first ground conductor 34 c at a portion corresponding to the tip of the loop coil 36 of the probe body 11.

Next, this is cut into a predetermined shape using a printed board similar to the above, and a printed board pattern of the adjusting mechanism 3 is formed as shown in FIG. The two printed circuit board patterns are sandwiched and bonded from both sides of the first transmission line 34 portion of the probe main body 11, and each printed circuit board pattern is interlayer-connected to the ground conductor 5 portion of the probe main body 11. FIG. 18B shows a cross section of a portion where the first transmission line 34 is sandwiched and bonded by two printed circuit board patterns from both sides. In FIG. 18B, the first transmission line 34 (the wiring patterns 11c ₁ and 11c ₂ are sandwiched between the copper foils 11a and 11e via the insulating layers 11b and 11d) is connected to the copper foil 11g via the insulating layer 11f. And the copper foil 11i through the insulating layer 11h. In the adjusting mechanism 3, the third insulator 3a corresponds to the insulating layers 11f and 11h, and the third ground conductor 3b corresponds to the copper foils 11g and 11i.

  If necessary, an SMA connector or the like is connected to the first and second probe output sides of the first and second transmission lines 34 and 2 of the probe body 11 to form an electromagnetic field probe.

  Similarly to the electromagnetic field probe shown in FIG. 9 according to the second modification of the first embodiment, in the configuration of FIG. 13, the common current blocking mechanism 13 may also be formed of a printed circuit board pattern.

  As described above, according to this example, with a simple single probe configuration, detailed magnetic field detection (first probe output) with high spatial resolution and electric field detection (second detection with high sensitivity and wide detection range). It is possible to appropriately perform both the probe output) and the electromagnetic field probe excellent in convenience using the printed circuit board, which can easily detect the desired electromagnetic field in a short time.

(Modification 4)
FIG. 19 is a schematic diagram schematically illustrating the configuration of an electromagnetic field probe according to Modification 4 of the third embodiment.
The electromagnetic field probe according to this example employs a configuration in which a calculation unit is added to the electromagnetic field probe according to the second modification of the third embodiment.

The electromagnetic field probe includes a first transmission line 34, a second transmission line 2, an adjustment mechanism 35, a common current blocking mechanism 4, a ground conductor 5, and a calculation unit 41.
In this example, the rear ends of the transmission lines 34A and 34B constituting the first transmission line 34 are cut shorter than in the second modification, and electrodes are arranged at the respective rear ends so that the output ends 34A1 and 34B1 are provided. Is formed. The output part of the first transmission line 34 is provided with electrodes and is used as first output parts 42A and 42B. A calculation unit 41 is connected between the output terminals 34A1 and 34B1 and the first output units 42A and 42B.

  The calculation unit 41 is, for example, a 180-degree hybrid circuit, and has a function of performing subtraction (A−B) and addition (A + B) of the outputs A and B from the output terminals 34A1 and 34B1. The differential signal generated by the subtraction is output from the first output unit 42A, and the addition signal generated by the addition is output from the first output unit 42B. The first probe output from the first output unit 42A is a magnetic field output with low spatial sensitivity but high spatial resolution. The first probe output from the first output unit 42B is an electric field output with high sensitivity but low sensitivity. On the other hand, the second transmission line 2 outputs a second probe output that is a high-sensitivity electric field output with a low spatial resolution from the second output unit 2A.

The measurement principle of the electric field and magnetic field by the electromagnetic field probe of this example will be described with reference to FIG.
As shown in FIG. 20 (a), the magnetic field generated by the current flowing through the wiring 51 to be measured passes through the loop coil 36, and when this magnetic flux is changed, the current flows in the opposite direction at both ends of the loop coil 36. Give birth. On the other hand, as shown in FIG. 20B, the electric field due to the voltage of the wiring 51 generates currents in the same direction at both ends of the loop coil 36. When current and voltage are generated simultaneously in the wiring 51, these two currents are overlapped and generated simultaneously. The magnetic field can be detected by calculating the differential signal component of the signal from both ends of the loop coil 36, and the electric field can be detected by calculating the added signal component.

  As described above, according to this example, a simple single probe configuration (the detection unit is only the gap 36a) enables detailed magnetic field detection and electric field detection (two types of first probe outputs) with high spatial resolution. High-sensitivity and wide detection range electric field magnetic field detection (second probe output) can be performed appropriately, and the electromagnetic field is highly convenient and can easily detect the desired electromagnetic field in a short time. The probe is realized.

  Note that the electromagnetic field probe according to the third embodiment and its various modifications is based on the electromagnetic field probe according to the second embodiment instead of the electromagnetic field probe according to the first embodiment. It is good also as a structure which formed the coil.

  In the first to third embodiments and the modifications described above, a changeover switch for switching and outputting one type of probe output may be provided. For example, this is assumed to be applied to the measuring device 104 having one input terminal (for example, only the input terminal 104a) in the electromagnetic field detection system of FIG.

  FIG. 21 shows a two-to-one correspondence to the electromagnetic field probe (referred to as electromagnetic field probe 10) of the first embodiment and the first and second modifications, the second embodiment, or the third embodiment and the first modification. The case where the changeover switch 61 is provided is shown. In this configuration, the two-to-one selector switch 61 is connected to two types of output units (first output unit and second output unit) of the electromagnetic field probe 10. For the 2-to-1 switch 61, for example, one of the output units is selected under the control of the control device 106 of the electromagnetic field detection system in FIG. 3, and an output signal from the selected output unit is input to the input terminal of the measurement device 104. input.

  FIG. 22 shows a case where a 3: 1 switch 62 corresponding to the electromagnetic field probe (referred to as the electromagnetic field probe 10) of the third embodiment and the modified examples 2, 3, or 4 is provided. In this configuration, the 3: 1 switch 62 is connected to three types of output units (two types of first output unit and second output unit) of the electromagnetic field probe 10. For the 3-to-1 switch 62, for example, one of the output units is selected by the control of the control device 106 of the electromagnetic field detection system in FIG. 3, and an output signal from the selected output unit is input to the input terminal of the measurement device 104. input.

  In the changeover switches 61 and 62, the output of the electromagnetic field probe 10 not connected to the measuring device 104 is connected to the termination resistor 63 in consideration of preventing the influence of the reflected signal and the like. As the change-over switches 61 and 62, switches using mechanical contacts, semiconductor switches such as MEMS switches, PIN diode switches, and GaAs switches can be used as small mechanical contact switches.

  In the first and second modified examples 1 and 2 and the third modified example 1 and 3, instead of using a printed circuit board for the electromagnetic field probe, a crystal substrate such as silicon or sapphire, a glass substrate, A ceramic substrate may be used. In this case, an electromagnetic field probe is manufactured using vapor deposition, sputtering, etching, lithography, or the like. It is also preferable to manufacture the electromagnetic field probe by combining a plurality of these substrates (including printed circuit boards).

  In the first embodiment, the first modification, the second embodiment, the third embodiment, and the first to fourth modifications, instead of using a ferromagnetic ferrite as the magnetic body of the common current interrupting mechanism, An artificial antiferromagnet synthesized with a ferromagnetic material or a multilayer film may be used. In this case, the high frequency characteristics can be further improved. Further, as the magnetic material of the common current blocking mechanism, two or more of ferromagnetic materials, antiferromagnetic materials, and artificial antiferromagnetic materials can be used in appropriate combination.

  Moreover, although it was set as the structure which pulls out a 2nd probe output from the 1st ground conductor of a 1st transmission line about all of the 1st-3rd embodiment and various modifications, the 2nd transmission line's 1st A structure in which the third probe output is extracted from the two ground conductors may be employed. Furthermore, a similar structure can be repeated to obtain a plurality of probe outputs of four or more types.

  Hereinafter, various aspects of the electromagnetic field probe are collectively described as supplementary notes.

(Supplementary Note 1) One end is an electromagnetic field detection unit, and is formed through a first signal line extending from the detection unit and an insulator along the extending direction of the first signal line. A first transmission line having a first ground conductor;
A common current cut-off mechanism provided in the first transmission line for cutting off the output of the common current of the first transmission line;
A second transmission line having a second signal line extending at one end to a portion between the detection unit of the first ground conductor and the common current interrupting mechanism;
The electromagnetic field probe, wherein the other end of the first signal line is a first output unit and the other end of the second signal line is a second output unit.

  (Supplementary note 2) The electromagnetic field probe according to supplementary note 1, wherein the common current interrupting mechanism is a magnetic body disposed on the first transmission line.

  (Supplementary note 3) The electromagnetic field probe according to supplementary note 1, wherein the common current cutoff mechanism is a local bent portion formed in the first transmission line.

(Supplementary Note 4) One end is an electromagnetic field detection unit, and is formed through a first signal line extending from the detection unit and an insulator along the extending direction of the first signal line. A first transmission line having a first ground conductor;
A second transmission line having a second signal line;
A common current cut-off mechanism that electromagnetically couples the first transmission line and one end of the second signal line to cut off a common current output of the first transmission line;
The electromagnetic field probe, wherein the other end of the first signal line is a first output unit and the other end of the second signal line is a second output unit.

  (Supplementary note 5) The electromagnetic field probe according to supplementary note 4, wherein the common current blocking mechanism made of a magnetic material and a coil formed at one end of the second signal line are electromagnetically coupled.

  (Supplementary note 6) The supplementary notes 1 to 5, wherein the second transmission line includes a second ground conductor formed through an insulator along an extending direction of the second signal line. The electromagnetic field probe according to any one of claims.

  (Supplementary Note 7) A third grounding conductor formed along the first transmission line via an insulator at a portion between the detection unit of the first transmission line and the common current blocking mechanism. The electromagnetic field probe according to any one of appendices 1 to 6, wherein the electromagnetic field probe is provided.

(Appendix 8) The first transmission line has a loop coil serving as the detection unit at a tip portion thereof.
The one end of the loop coil is connected to the first signal line, and the other end of the loop coil is connected to the first ground conductor. Electromagnetic field probe.

(Supplementary note 9) Further includes a changeover switch connected to the first output unit and the second output unit,
The electromagnetic field probe according to any one of appendices 1 to 8, wherein the change-over switch outputs the selected output from one of the first output unit and the second output unit.

(Supplementary Note 10) The first transmission line has two first signal lines arranged in parallel, and has a loop coil serving as the detection unit at a tip portion thereof.
Any one of Supplementary notes 1 to 7, wherein one end of the loop coil is connected to one of the first signal lines, and the other end of the loop coil is connected to the other first signal line. The electromagnetic field probe according to item.

(Supplementary note 11) Further includes an arithmetic unit connected to the first output unit of one of the first signal lines and the first output unit of the other of the first signal lines,
The calculation unit includes a difference value and an addition value between an output from the first output unit of one of the first signal lines and an output from the first output unit of the other first signal line. 11. The electromagnetic field probe according to appendix 10, wherein each of the electromagnetic field probes is calculated and output.

(Supplementary note 12) Further includes a changeover switch connected to the two types of the first output unit and the second output unit,
12. The electromagnetic field probe according to appendix 10 or 11, wherein the change-over switch outputs a selected one of the two types of the first output unit and the second output unit.

1, 31, 34 First transmission lines 1a, 31a, 34a First signal lines 1b, 31b, 34b First insulators 1c, 31c, 34c First ground conductor 1d Connection part 1A Detectors 1B, 31A, 34C, 42A, 42B 1st output part 1C, 34D Protruding part 2 2nd transmission line 2a 2nd signal line 2b 2nd insulator 2c 2nd ground conductor 2A 2nd output part 3,35 Adjustment mechanism 3a, 35a Third insulators 3b, 35b Third ground conductors 4, 13 Common current blocking mechanisms 4a, 4b Through hole 5 Ground (ground) conductor 5a End 5b Opening 10 Electromagnetic probe 11, 14 Probe body 11a , 11e, 11g, 11i copper foil 11b, 11d, 11f, 11h insulating layer 11c, 11c _1, 11c ₂ wiring pattern 21 pickup coil 32,33,3 6, 37 Loop coils 32a, 36a Gap 33a End portion 33b Conductor rods 34A, 34B Transmission lines 34A1, 34B1 Output end 37c Conductor rod 41 Arithmetic units 51, 107 Wiring 61 2-to-1 selector switch 62 3-to-1 selector switch 63 Terminating resistor DESCRIPTION OF SYMBOLS 100 Printed circuit board 101 Probe stage 102 Probe moving mechanism 103 Stage controller 104 Measuring equipment 104a, 104b Input terminal 105 Observation equipment 106 Control equipment

Claims (5)

One end is an electromagnetic field detection unit, a first signal line extending from the detection unit, and a first signal line formed through an insulator along the extending direction of the first signal line. A first transmission line having a ground conductor;
A common current cut-off mechanism provided in the first transmission line for cutting off the output of the common current of the first transmission line;
A second transmission line having a second signal line extending at one end to a portion between the detection unit of the first ground conductor and the common current interrupting mechanism;
The electromagnetic field probe, wherein the other end of the first signal line is a first output unit and the other end of the second signal line is a second output unit.   The electromagnetic field probe according to claim 1, wherein the common current cut-off mechanism is a magnetic body disposed on the first transmission line.   The electromagnetic field probe according to claim 1, wherein the common current cut-off mechanism is a local bent portion formed in the first transmission line. One end is an electromagnetic field detection unit, a first signal line extending from the detection unit, and a first signal line formed through an insulator along the extending direction of the first signal line. A first transmission line having a ground conductor;
A second transmission line having a second signal line;
A common current cut-off mechanism that electromagnetically couples the first transmission line and one end of the second signal line to cut off a common current output of the first transmission line;
The electromagnetic field probe, wherein the other end of the first signal line is a first output unit and the other end of the second signal line is a second output unit. The first transmission line has a loop coil serving as the detection unit at a tip portion thereof,
5. The device according to claim 1, wherein one end of the loop coil is connected to the first signal line, and the other end of the loop coil is connected to the first ground conductor. The electromagnetic field probe as described.

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