CN213069018U

CN213069018U - Magnetic field probe

Info

Publication number: CN213069018U
Application number: CN202021900426.XU
Authority: CN
Inventors: 杨红波; 戴林军; 盛俊; 陈俊飞; 熊麟彪; 殷佳成
Original assignee: Yangxin Technology Shenzhen Co ltd
Current assignee: Yangxin Technology Shenzhen Co ltd
Priority date: 2020-09-03
Filing date: 2020-09-03
Publication date: 2021-04-27
Anticipated expiration: 2030-09-03

Abstract

The embodiment of the utility model discloses magnetic field probe, include: a connector comprising a first end and a second end; the coil part is formed by connecting a plurality of layers of coils in a first PCB area according to a preset mode and comprises a first interface and a second interface; an extension including a first wire and a second wire, the extension connected between the first PCB region and the connector, the first interface connected to a first end of the connector through the first wire; the second interface is connected to the second end of the connector by the second wire. The embodiment of the utility model can complete the magnetic field measurement with high sensitivity by inducing the magnetic field through the multilayer coil structure; the size of the coil can be designed according to actual needs, and high position resolution measurement can be realized; the signal is transmitted through the middle strip line structure, so that the signal transmission loss is reduced; through the design of shielding via hole, improve signal transmission's interference killing feature.

Description

Magnetic field probe

Technical Field

The utility model relates to a test equipment technical field especially relates to a magnetic field probe.

Background

Modern electronic technology has higher and higher requirements on electromagnetic compatibility of electronic systems, and not only electronic equipment is required not to generate interference on other equipment, but also certain anti-interference capability on electromagnetic radiation of other equipment is required. In order to locate the interference source of the external electromagnetic radiation, a near-field test method is usually adopted to locate the interference source.

Near field testing requires the use of an electromagnetic field probe as a test tool. The main test component is the coil of the probe, and the larger the coil, the more the magnetic induction lines pass through, and the more sensitive the probe is. However, in near field testing, the magnetic field varies greatly with distance, which requires the probe to be small enough to achieve good spatial resolution. The traditional near-field probe adopts a small measuring antenna, a semi-rigid coaxial line is wound into a circular ring at the position of the probe, the structure is single, and both sensitivity and spatial resolution cannot be considered.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the present invention provides a magnetic field probe, so that the probe not only has higher sensitivity, but also has better spatial resolution.

An embodiment of the utility model provides a magnetic field probe, include:

a connector comprising a first end and a second end;

the coil part is formed by connecting a plurality of layers of coils in a first PCB area according to a preset mode and comprises a first interface and a second interface;

an extension including a first wire and a second wire, the extension connected between the first PCB region and the connector, the first interface connected to a first end of the connector through the first wire; the second interface is connected to the second end of the connector by the second wire.

Further, the extension part is formed in a second PCB region, and the second PCB region and the first PCB region are two regions of an integrally formed PCB board.

Further, the PCB board includes first layer, second floor, third layer and fourth layer, the coil via hole corresponding position of the first layer, second floor, third layer and the fourth layer in first PCB region all is equipped with 5 coil via holes, and wherein, 4 coil via holes form square pattern, and another coil via hole is located square pattern is outside.

Furthermore, the regional first layer of second PCB is being close to the one end of connecting portion is equipped with the pad, the regional second layer of second PCB, third layer and fourth layer with the corresponding position of the regional first layer of second PCB all is equipped with the pad via hole, the pad via hole with the pad is connected.

Further, the first layer of the second PCB region includes a first grounding region, the fourth layer of the second PCB region includes a second grounding region, the second grounding region is connected with the grounding coil via hole of the fourth layer of the first PCB region, and the grounding coil via hole is a coil via hole connected with the second grounding region in the fourth layer of the first PCB region.

Further, the first interface is arranged at a coil through hole of the second layer of the first PCB area, and the second interface is arranged at the grounding coil through hole.

Further, the coil portion is formed by a multilayer coil formed by connecting the first interface and the second interface in a preset spiral and through hole manner.

Further, the first wire and the second wire are provided as an intermediate strip line, and the first end and the second end of the connector are provided as the same interface end; one end of the middle strip line is connected with the through hole of the pad of the second layer of the second PCB area, and the interface end is connected with the pad of the first layer of the second PCB area.

Further, the other end of the middle strip line is connected with the first interface.

Furthermore, the first layer, the second layer, the third layer and the fourth layer of the second PCB area are all provided with a plurality of shielding through holes, and the shielding through holes are symmetrically distributed along the middle strip line.

The magnetic field probe provided by the embodiment of the utility model can complete the magnetic field measurement with high sensitivity by inducing the magnetic field through the multilayer coil structure; the size of the coil can be designed according to actual needs, and high position resolution measurement can be realized; the signal is transmitted through the middle strip line structure, so that the signal transmission loss is reduced; through the design of shielding via hole, improve signal transmission's interference killing feature.

Drawings

Fig. 1 is a schematic structural diagram of a magnetic field probe according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another magnetic field probe according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a first layer of a PCB board according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a second layer of a PCB board according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a third layer of the PCB according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a third layer of the PCB according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a first layer of conductive wires of a coil portion according to an embodiment of the present invention;

fig. 8 is a schematic view of an internal structure of a magnetic field probe according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features for distinguishing between descriptive features, non-sequential, non-trivial and non-trivial. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The specific structure of the magnetic field probe according to the embodiment of the present invention will be described below with reference to fig. 1 to 7.

As shown in fig. 1, the embodiment of the present invention provides a magnetic field probe, including: the connector 100, the coil part 200, and the extension part 300, the connector 100 and the coil part 200 being connected by the extension part 300.

The coil part 200 is formed by connecting a plurality of layers of coils, which are provided in a first PCB region (not shown in fig. 1), in a predetermined manner. The coil part 200 includes a first interface 201 and a second interface 202, the first interface 201 being a start end of the multilayer coil constituting the coil part 200, and the second interface 202 being an end of the multilayer coil constituting the coil part 200.

The extension part 300 has a length for connecting the first PCB region and the connector 100, that is, connecting the coil part 200 and the connector 100. Extension 300 includes a first conductor 301 and a second conductor 302, and connector 100 includes a first end 101 and a second end 102. The first interface 201 is connected to the first end 101 of the connector 100 by a first wire 301; the second interface 202 is connected to the second end 102 of the connector 100 by a second wire 302. Then, a circuit is formed between the coil part 200 and the connector 100.

In performing near field testing (e.g., radio frequency interference detection), the multi-layer coil of the coil portion 200 detects changes in the magnetic field in the test area, the changing magnetic field causes the multi-layer coil to form an electrical signal that is transmitted to the connector 100 through a loop between the coil portion 200 and the connector 100, and the connector 100 may be connected to an external analysis device to transmit the electrical signal to the external analysis device to analyze the changes in the magnetic field in the test area.

In one embodiment, as shown in fig. 2, the extension 300 is formed on the second PCB region 420, the second PCB region 420 and the first PCB region 410 are integrally formed into two regions of the PCB 400, that is, the coil part 200 is located on the first PCB region 410 of the PCB 400, and the extension 300 is located on the second PCB region 420 of the PCB 400. The PCB 400 has a multi-layer PCB structure, in this embodiment, the PCB 400 has a 4-layer PCB structure, and in other embodiments, the PCB 400 may also have a 6-layer, 8-layer or more-layer PCB structure. In other embodiments, the second PCB area 420 and the first PCB area 410 may also be a single-layer PCB board or a multi-layer PCB board.

It will be appreciated that in one aspect, PCB 400 is divided into two areas, namely a first PCB area 410 and a second PCB area 420. On the other hand, the PCB 400 has 4 layers, i.e., a first layer L1, a second layer L2, a third layer L3, and a fourth layer L4. Then, 4 layers should be included for each region of the PCB panel 400, and two regions should be included for each layer of the PCB panel 400. That is, the first PCB region of the first layer L1 and the first layer L1 of the first PCB region of the PCB panel 400 mean the same, and the other layers and regions are also represented.

Referring to fig. 3-6, in a specific embodiment, fig. 3 illustrates a structure of a first layer L1 of the PCB 400, fig. 4 illustrates a structure of a second layer L2 of the PCB 400, fig. 5 illustrates a structure of a third layer L3 of the PCB 400, and fig. 6 illustrates a structure of a fourth layer L4 of the PCB 400.

Referring also to fig. 3, the first-layer wire 231 of the coil part 200 is provided in the first PCB region 410 of the first layer L1. The first PCB area 410 of the first layer L1 is provided with 5 coil vias, wherein 4 coil vias are symmetrically distributed along the center line of the PCB 400 and form a square pattern, and the other coil via is located outside the square pattern. It can be understood that the layout of the 5 coil vias of the second, third and fourth layers L2, L3 and L4 of the PCB 400 is the same as that of the first layer L1. Accordingly, the second-layer wire 232 of the coil part 200 is disposed in the first PCB region 410 of the second layer L2, the third-layer wire 233 of the coil part 200 is disposed in the first PCB region 410 of the third layer L3, and the fourth-layer wire 234 of the coil part 200 is disposed in the first PCB region 410 of the fourth layer L4, as shown in fig. 4 to 6.

As shown in fig. 3, the second PCB region 420 of the first layer L1 is provided with a plurality of shielded vias 320 symmetrically distributed along the centerline of the PCB board 400. It is understood that the second layer L2, the third layer L3, and the fourth layer L4 of the PCB 400 are each provided with a plurality of shielded vias 320 distributed along the center line of the corresponding layer, as shown in fig. 4-6. As shown in fig. 3, the second PCB region 420 of the first layer L1 is also provided with a plurality of pads 311. And a plurality of pad vias 312 are formed in each of the second layer L2, the third layer L3, and the fourth layer L4 of the PCB 400, as shown in fig. 4-6. Pad via 312 may be connected with pad 311.

As shown in fig. 3, the first layer L1 of the PCB 400 is also provided with a first ground area 510. As shown in fig. 6, the fourth layer L4 of the PCB 400 is further provided with a second ground area 520. The first and

second ground areas

510 and 520 are each copper clad such that the first and fourth layers L1 and L4 form ground layers, respectively.

Since the corresponding positions of the first PCB region 410 of the first layer L1, the second layer L2, the third layer L3, and the fourth layer L4 are all provided with 5 coil via holes, for convenience of description, the 5 coil via holes of the first layer L1 are respectively labeled as a layer of coil via hole K10, a layer of coil via hole K11, a layer of coil via hole K12, a layer of coil via hole K13, and a layer of coil via hole K14, as shown in fig. 3. The 5 coil vias of the second layer L2 are respectively labeled as a two-layer coil via K20, a two-layer coil via K21, a two-layer coil via K22, a two-layer coil via K23 and a two-layer coil via K24, as shown in fig. 4. The 5 coil vias of the third layer L3 are respectively labeled as a three-layer coil via K30, a three-layer coil via K31, a three-layer coil via K32, a three-layer coil via K33 and a three-layer coil via K34, as shown in fig. 5. The 5 coil vias of the fourth layer L4 are respectively labeled as a four-layer coil via K40, a four-layer coil via K41, a four-layer coil via K42, a four-layer coil via K43, and a four-layer coil via K44, as shown in fig. 6.

In the present embodiment, the coil portion 200 is formed of a multilayer coil formed by connecting the first interface 201 and the second interface 202 in a predetermined spiral and through-hole manner. Specifically, the first interface 201 of the coil part 200 is provided at the coil via hole K10 of one layer in the first layer L1, that is, the starting end of the multilayer coil is located at the coil via hole K10 of one layer in the first layer L1, as shown in fig. 3.

The first-layer wire 231 of the coil portion 200 passes from the first-layer coil via K10 in the first layer L1, sequentially bypasses the first-layer coil via K11 and the first-layer coil via K12 in the first layer L1, and passes from the first-layer coil via K13 to the second-layer coil via K23 in the second layer L2. The second-layer lead 232 of the coil portion 200 passes from the second-layer coil via K23 in the second layer L2, passes through the second-layer coil via K24 and the second-layer coil via K21 in this order, and passes through the second-layer coil via K22 to the third-layer coil via K32 in the third layer L3. The third-layer wire 233 of the coil portion 200 passes from the third-layer coil via hole K32 in the third layer L3, sequentially passes around the third-layer coil via hole K33 and the third-layer coil via hole K34, and passes from the third-layer coil via hole K31 to the fourth-layer coil via hole K41 in the fourth layer L4. The fourth layer of wires 234 of the coil part 200 starts from the four-layer coil via hole K41 in the fourth layer L4, sequentially bypasses the four-layer coil via hole K42 and the four-layer coil via hole K43, and finally is connected to the four-layer coil via hole K44, that is, the second interface 202 of the coil part 200 is provided at the four-layer coil via hole K44 in the fourth layer L4. Among them, the four-layer coil via K44 in the fourth layer L4 is connected to the second ground region 520, that is, the four-layer coil via K44 in the fourth layer L4 is a ground coil via, so that the coil portion 200 forms a loop with the ground.

Further, in the above embodiment, the first layer of the conductive wires 231 sequentially bypasses the first layer of the coil via hole K11 and the first layer of the coil via hole K12, which means that the first layer of the conductive wires 231 should avoid corresponding holes when passing through the first layer of the coil via hole K11 and the first layer of the coil via hole K12, so as to avoid forming a connection relationship, as shown in fig. 7. It is understood that the second layer wire 232, the third layer wire 233 and the fourth layer wire 234 all bypass the corresponding coil vias in the same manner as shown in fig. 7.

It is understood that the multi-layer coil described in the above embodiments is only one of the preset spiral and perforation connection modes, and in practical use, a person skilled in the art may form a multi-layer coil structure according to other spiral and perforation connection modes of the wiring form.

As shown in fig. 4, in the second layer L2 of the PCB 400, the middle strip line 310 is provided. One end of the intermediate strip line 310 is connected to the pad via 312 in the second layer L2, and the other end passes through the two-layer coil via K20 in the second layer L2 to be connected to the one-layer coil via K10 in the first layer L1. As shown in fig. 4, the middle strip line 310 is disposed along the central line of the PCB 400, so that the plurality of shielding vias 320 are symmetrically distributed along the middle strip line 310, and the arrangement enables the middle strip line 310 to shield external interference during signal transmission, thereby improving the anti-interference capability of signal transmission.

In this embodiment, the two ports (the first end 101 and the second end 102) of the connector 100 are provided as the same interface end, and the interface end is welded with the pad 311 in the first layer L1. The connector 100 may be connected to the pad via 312 of the second layer L2 through the pad 311 of the first layer L1, and the pad via 312 of the second layer L2 connects to the intermediate stripline 310, so that the connector 100 makes a connection to the intermediate stripline 310. In this embodiment, the connector 100 is soldered to the pad 311 in the first layer L1 of the PCB 400, and then the intermediate strip line 310 is connected through the pad 311 of the second layer L2 connected to the pad 311. That is, the middle strip line 310 unites the first and second

conductive lines

301 and 302 of the extension 300 into one. The intermediate strip line 310 connects the first interface 201 of the multilayer coil of the coil section 200 at the one-layer coil via K10 in the first layer L1, and the second interface 202 of the multilayer coil of the coil section 200 is finally grounded. Thus, the connector 100, the intermediate strip line 310, the coil portion 200, and the ground form a circuit, as shown in the schematic view of the internal structure of the magnetic field probe in fig. 8. In performing the near field test, the multi-layer coil of the coil part 200 detects a change in magnetic field in the test area, the changed magnetic field causes the multi-layer coil to form an electrical signal, which is transmitted to the connector 100 through the intermediate strip line 310, and the connector 100 may be connected to an external analysis device to transmit the electrical signal to the external analysis device to analyze the change in magnetic field in the test area. For example, the connector 100 is an SMA connector that is connectable to an external analysis device via a radio frequency wire.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims

1. A magnetic field probe, comprising:

a connector comprising a first end and a second end;

2. The magnetic field probe according to claim 1, wherein the extension is formed in a second PCB region, the second PCB region and the first PCB region being two regions of an integrally formed PCB board.

3. The magnetic field probe according to claim 2, wherein the PCB board comprises a first layer, a second layer, a third layer and a fourth layer, wherein 5 coil vias are provided at corresponding positions of the first layer, the second layer, the third layer and the fourth layer of the first PCB region, wherein 4 coil vias form a square pattern, and the other coil via is located outside the square pattern.

4. The magnetic field probe of claim 3, wherein the first layer of the second PCB region is provided with a pad at an end near the connector, and wherein the second, third and fourth layers of the second PCB region are provided with a pad via at a position corresponding to the first layer of the second PCB region, and wherein the pad via is connected to the pad.

5. The magnetic field probe according to claim 4, wherein the first layer of the second PCB region comprises a first ground region and the fourth layer of the second PCB region comprises a second ground region, the second ground region being connected to the ground coil via of the fourth layer of the first PCB region, the ground coil via being a coil via in the fourth layer of the first PCB region that is connected to the second ground region.

6. The magnetic field probe according to claim 5, wherein the first interface is provided at a coil via of the second layer of the first PCB region and the second interface is provided at the ground coil via.

7. The magnetic field probe according to claim 6, wherein the coil part is constituted by a multi-layer coil formed between the first interface and the second interface in such a manner that a predetermined spiral and a perforation are connected.

8. The magnetic field probe according to claim 6, wherein the first wire and the second wire are provided as an intermediate ribbon wire, the first end and the second end of the connector being provided as the same interface end; one end of the middle strip line is connected with the through hole of the pad of the second layer of the second PCB area, and the interface end is connected with the pad of the first layer of the second PCB area.

9. The magnetic field probe according to claim 8, wherein the other end of the intermediate stripline is connected to the first interface.

10. The magnetic field probe according to claim 8, wherein the first, second, third and fourth layers of the second PCB region are each provided with a plurality of shielded vias symmetrically distributed along the intermediate stripline.