Signal measurement circuit device

Abstract

A signal measurement circuit device includes a circuit board structure and a multi-conductor transmission line segment, a high-frequency measurement probe segment and a conversion segment formed by the circuit board structure, wherein the conversion segment is arranged between the multi-conductor transmission line segment and the high-frequency measurement probe segment to connect to the multi-conductor transmission line segment and the high-frequency measurement probe segment. The high-frequency measurement probe segment includes a group of high-frequency measurement probes; the group of high-frequency measurement probes are arranged on a first metal layer of the circuit board structure to contact a high-frequency probe to transmit a high-frequency signal. A second metal layer of the circuit board structure defines a slot; the slot is arranged corresponding to the high-frequency measurement probe segment and the conversion segment to assist a mode conversion between the high-frequency probe and the multi-conductor transmission line segment.

Description

Technical Field

[0001] The invention relates to a circuit device, in particular to a signal measuring circuit device. Background Art

[0002] During the design and testing phase of high-frequency components, high-frequency probes are used to measure high-frequency components. The most commonly used high-frequency probes are probes with a ground-signal-ground (usually referred to as GSG) arrangement, such as Figure 3 As shown (high frequency probe 20), its operating mode can directly correspond to the coplanar waveguide (CPW) transmission line of the related art. Figure 4 , which is a cross-sectional view of the coplanar waveguide field pattern mode of the related technology.

[0003] The coplanar waveguide transmission line of the related art has the advantage of low loss at high frequencies; however, on many high-frequency substrates, considering many factors, such as substrate thickness and multilayer board integration, the microstrip line of the related art and the grounded coplanar waveguide (usually referred to as GCPW) of the related art are more commonly used transmission lines. Please refer to Figure 5 , which is a cross-sectional view of a microstrip line field mode of the related art and a grounded coplanar waveguide field mode of the related art, wherein Figure 5 The upper part of the figure shows the microstrip line field mode cross-section of the related art, while Figure 5 The lower part of the figure shows the field mode section of the grounded coplanar waveguide in the related art. Especially in the millimeter wave frequency band, considering many factors such as radiation loss and high-frequency signal coupling, the grounded coplanar waveguide in the related art is the most commonly used transmission line.

[0004] The structure of the grounded coplanar waveguide of the related art is similar to that of the coplanar waveguide of the related art, but the operating mode of the grounded coplanar waveguide of the related art is different from the operating mode of the coplanar waveguide of the related art; the operating mode of the grounded coplanar waveguide of the related art is similar to the operating mode of the microstrip line of the related art, and more energy is stored in the substrate; therefore, when a probe with a ground-signal-ground arrangement is used to probe the transmission line of the grounded coplanar waveguide of the related art, mode conversion loss and impedance mismatch will occur; generally speaking, the higher the frequency, the more serious the above problems are, and excessive reflection and loss will reduce the accuracy of high-frequency measurement. Summary of the invention

[0005] To solve the above problems, an object of the present invention is to provide a signal measuring circuit device.

[0006] To achieve the above-mentioned object of the present invention, the signal measurement circuit device of the present invention is applied to a high-frequency probe, and the signal measurement circuit device comprises: a circuit board structure; a multi-conductor transmission line segment, the multi-conductor transmission line segment is formed by the circuit board structure; a high-frequency measurement probe segment, the high-frequency measurement probe segment is formed by the circuit board structure; and a conversion segment, the conversion segment is formed by the circuit board structure, the conversion segment is arranged between the multi-conductor transmission line segment and the high-frequency measurement probe segment to connect to the multi-conductor transmission line segment and the high-frequency measurement probe segment, wherein the circuit board structure comprises: A first metal layer; a second metal layer; a dielectric layer, the dielectric layer is arranged between the first metal layer and the second metal layer; and a plurality of vias, the vias are connected to the first metal layer and the second metal layer, wherein the high-frequency measurement probe segment includes a group of high-frequency measurement probes; the group of high-frequency measurement probes are arranged on the first metal layer to contact the high-frequency probe to transmit a high-frequency signal; the second metal layer defines a slot; the slot is arranged corresponding to the high-frequency measurement probe segment and the conversion segment to assist a mode conversion between the high-frequency probe and the multi-conductor transmission line segment.

[0007] Furthermore, in a specific embodiment of the signal measuring circuit device of the present invention as described above, the circuit board structure can be, for example, but the present invention is not limited to, a multi-layer circuit board including at least three metal layers.

[0008] Furthermore, in a specific embodiment of the signal measurement circuit device of the present invention as described above, the set of high-frequency measurement probes can be, for example, but the present invention is not limited to, a set of probes arranged as ground-signal-ground (usually referred to as GSG).

[0009] Furthermore, in a specific embodiment of the signal measuring circuit device of the present invention as described above, the multi-conductor transmission line segment can be, for example, but the present invention is not limited to, a grounded co-planar waveguide (GCPW) structure.

[0010] Furthermore, in a specific embodiment of the signal measuring circuit device of the present invention as described above, the multi-conductor transmission line segment can be, for example, but the present invention is not limited to, a microstrip structure.

[0011] Furthermore, in a specific embodiment of the signal measurement circuit device of the present invention as described above, the slot has a width; if the width of the slot is closer to the multi-conductor transmission line segment, the width of the slot is narrower; if the width of the slot is closer to the high-frequency measurement probe segment, the width of the slot is wider.

[0012] Furthermore, in a specific embodiment of the signal measuring circuit device of the present invention as described above, the slot can be, for example, but the present invention is not limited to, a triangular shape.

[0013] Furthermore, in a specific embodiment of the signal measuring circuit device of the present invention as described above, the high-frequency measuring probe section includes a portion of the vias connected to the first metal layer and the second metal layer.

[0014] The invention has the effect of reducing the loss of mode conversion to improve the accuracy of high-frequency measurement.

[0015] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. 4 is a schematic diagram of a specific embodiment of a signal measurement circuit device of the present invention.

[0017] Figure 2 It is an exploded view of a specific embodiment of the metal layer of the circuit board structure of the present invention.

[0018] Figure 3 The figure is a schematic diagram of a specific embodiment of the signal measurement circuit device of the present invention applied to a high-frequency probe.

[0019] Figure 4 It is a cross-sectional view of the coplanar waveguide field pattern mode of the related technology.

[0020] Figure 5 It is a cross-sectional view of a microstrip line field mode of the related art and a grounded coplanar waveguide field mode of the related art.

[0021] Figure 6 This is a cross-sectional diagram of the electric field vector of a ground plane without slots in the related art.

[0022] Figure 7 This is a cross-sectional view of the electric field vector when the ground plane of the present invention has grooves.

[0023] Figure 8 Schematic diagram of various grooves of the second metal layer of the present invention.

[0024] Fig. 9 It is an exploded view of another specific embodiment of the circuit board structure of the present invention from a certain perspective.

[0025] Fig.10 It is an exploded view of another specific embodiment of the circuit board structure of the present invention from another perspective.

[0026] Wherein, the reference numerals are:

[0027] 10: Signal measurement circuit device

[0028] 20: High frequency probe

[0029] 30: Circuit board structure

[0030] 40:Multi-conductor transmission line segment

[0031] 50:Conversion segment

[0032] 60: High frequency measurement probe section

[0033] 302: First metal layer

[0034] 304: Dielectric layer

[0035] 306: Second metal layer

[0036] 308: Through hole

[0037] 310: Slotting

[0038] 312: Width

[0039] 314: Clearance Zone

[0040] 316: Length

[0041] 318: Sub-dielectric layer

[0042] 402: Grounded coplanar waveguide

[0043] 602: High frequency measurement probe point DETAILED DESCRIPTION

[0044] The structural principle and working principle of the present invention are described in detail below in conjunction with the accompanying drawings:

[0045] In this specification, many specific details are provided to provide a thorough understanding of the specific embodiments of the present invention; however, those skilled in the art should know that the present invention can still be practiced without one or more of these specific details; in other cases, well-known details are not shown or described to avoid obscuring the main technical features of the present invention. The technical content and detailed description of the present invention are described as follows with the accompanying drawings:

[0046] Figure 1 is a schematic diagram of a specific embodiment of the signal measurement circuit device of the present invention, Figure 2 This is an exploded view of a specific embodiment of the metal layer of the circuit board structure of the present invention. Figure 3 This is a schematic diagram of a specific embodiment of the signal measurement circuit device of the present invention applied to a high-frequency probe. Please also refer to Figure 1 , Figure 2 and Figure 3A signal measurement circuit device 10 of the present invention is applied to a high-frequency probe 20, and the signal measurement circuit device 10 includes a circuit board structure 30, a multi-conductor transmission line segment 40, a conversion segment 50 and a high-frequency measurement probe segment 60; the multi-conductor transmission line segment 40 is formed by the circuit board structure 30, the high-frequency measurement probe segment 60 is formed by the circuit board structure 30, the conversion segment 50 is formed by the circuit board structure 30, and the conversion segment 50 is arranged between the multi-conductor transmission line segment 40 and the high-frequency measurement probe segment 60 to connect to the multi-conductor transmission line segment 40 and the high-frequency measurement probe segment 60. Figure 1 , Figure 2 and Figure 3 This is only a partial schematic diagram, and Figure 1 , Figure 2 and Figure 3 The right side of the PCB is connected to the high-frequency component to be tested (not shown in the figure); for example, refer to Fig. 9 or Fig.10 The circuit board structure 30 is connected to a high-frequency component to be tested (not shown in the figure) through another high-frequency probe 20.

[0047] The circuit board structure 30 includes a first metal layer 302, a dielectric layer 304, a second metal layer 306 (for example, a ground layer) and a plurality of vias 308; the dielectric layer 304 is disposed between the first metal layer 302 and the second metal layer 306; the vias 308 are connected to the first metal layer 302 and the second metal layer 306. The high-frequency measurement probe segment 60 includes a group of high-frequency measurement probes 602; the group of high-frequency measurement probes 602 are disposed on the first metal layer 302 to contact the high-frequency probe 20 to transmit a high-frequency signal. The second metal layer 306 defines a slot 310; the slot 310 is disposed corresponding to the high-frequency measurement probe segment 60 and the conversion segment 50 to assist a mode conversion between the high-frequency probe 20 and the multi-conductor transmission line segment 40. For simplicity, Figure 2 The vias 308 are not drawn on the second metal layer 306 .

[0048] The circuit board structure 30 may be, for example, but the present invention is not limited to, a multi-layer circuit board including at least three metal layers. The group of high-frequency measurement probe points 602 may be, for example, but the present invention is not limited to, a group of probe points arranged as ground-signal-ground (usually referred to as GSG). The multi-conductor transmission line segment 40 may be, for example, but the present invention is not limited to, a grounded co-planar waveguide (usually referred to as GCPW) structure or a microstrip structure. The slot 310 has a width 312; if the width 312 of the slot 310 is closer to the multi-conductor transmission line segment 40, the width 312 of the slot 310 is narrower; if the width 312 of the slot 310 is closer to the high-frequency measurement probe point segment 60, the width 312 of the slot 310 is wider. The slot 310 may be, for example, but the present invention is not limited to, a triangular shape. The high frequency measurement probe section 60 includes a portion of the vias 308 connected to the first metal layer 302 and the second metal layer 306 .

[0049] Furthermore, please refer to Figure 8 , which is a schematic diagram of various slots of the second metal layer of the present invention. The slot 310 can be, for example, but the present invention is not limited to, an isosceles triangle, a trapezoid, an area surrounded by an arc / parabola / involute and a straight line, or a keyhole shape; basically, the portion adjacent to the multi-conductor transmission line segment 40 is narrow, and the portion adjacent to the high-frequency measurement probe segment 60 is wide, so as to achieve the purpose of adjusting the current distribution and the field mode.

[0050] If the multi-conductor transmission line segment 40 is the grounded coplanar waveguide structure, then Figure 3 As shown, the multi-conductor transmission line segment 40 includes a grounded coplanar waveguide 402, and its transmission line characteristic impedance is generally designed as the standard impedance of the measurement system, which is used to import or export the high-frequency signal of the high-frequency component to be measured. The size and spacing of the group of high-frequency measurement probes 602 of the high-frequency measurement probe segment 60 measured by the high-frequency probe 20 need to match the spacing of the high-frequency probe 20. The conversion segment 50 is used to handle the gradual change of the geometry and impedance of the multi-conductor transmission line segment 40 and the high-frequency measurement probe segment 60; in some lower frequency applications, the conversion segment 50 may be omitted.

[0051] In one example, the second metal layer 306 is a complete ground plane (i.e., without the slot 310), and the second metal layer 306 has the vias 308 connected to the ground plane of the first metal layer 302; since the ground plane of the second metal layer 306 is below the high-frequency measurement probe section 60, the mode is still in the form of a grounded coplanar waveguide, and a lot of energy is stored between the signal line and the ground plane of the second metal layer 306; since it cannot be converted into a coplanar waveguide mode of a ground-signal-ground probe, impedance mismatch and loss occur. Please refer to Figure 6 , which is a cross-sectional diagram of the electric field vector of a ground plane without slots in the related art.

[0052] In another example, the ground plane of the second metal layer 306 below the high-frequency measurement probe section 60 and the ground plane of the second metal layer 306 below the conversion section 50 are completely removed (or, the ground plane of the second metal layer 306 below the high-frequency measurement probe section 60 is completely removed, and the ground plane of the second metal layer 306 below the conversion section 50 is partially (gradually) removed), so that it can be converted into a coplanar waveguide mode; however, since the ground plane of the second metal layer 306 is largely removed, the spacing of the coplanar waveguide of the high-frequency measurement probe section 60 is limited by the process and cannot be very narrow, which easily generates more radiation loss of high-frequency signals; that is, due to the process limitation of the printed circuit board, the lower limit of the spacing (gap) of the same layer of metal is 3 to 4 mils, and the coplanar waveguide structure formed by this spacing is prone to radiation leakage at the continuous boundary of the ground plane of the second metal layer 306. Furthermore, sufficient clearance is required under the removed ground plane of the second metal layer 306 (including the board thickness direction and the lateral direction) to avoid high-frequency signal coupling and reflection interference, which is not conducive to the test structure integrated into the system in the form of a test coupon or the design that is sensitive to the board thickness. Considering the process line width limitation, multi-layer board integration, system integration, etc., it is necessary to develop the signal measurement circuit device 10 that can take into account both measurement performance and required space.

[0053] The signal measurement circuit device 10 of the present invention is a new signal measurement circuit device design, which cleverly designs the shape and position of the slot 310 of the second metal layer 306 to effectively adjust the high-frequency signal mode, reduce the requirements for the clearance area, and reduce radiation loss and coupling. The signal measurement circuit device 10 of the present invention includes the following features:

[0054] 1. The slot 310 of the second metal layer 306 (ground layer) starts at the conversion section 50 and ends at the high-frequency measurement probe section 60; the width 312 of the slot 310 is narrow at the front and wide at the back to assist the field pattern conversion between the grounded coplanar waveguide mode of the transmission line and the coplanar waveguide mode of the ground-signal-ground probe; the width 312 of the slot 310 and a length 316 (such as Figure 2 As shown in FIG. 1 , the RF power supply ( FIG. 14 ) can be optimized according to the required frequency band to obtain better bandwidth characteristics.

[0055] 2. The periphery of the slot 310 of the second metal layer 306 is surrounded by the vias 308 connecting the first metal layer 302 and the second metal layer 306 to maintain the ground planes of each layer at the same potential and prevent high-frequency signals from radiating and leaking to the outside.

[0056] 3. Fig. 9 FIG. 1 is an exploded view of another specific embodiment of the circuit board structure of the present invention from a perspective. Fig.10 is an exploded view of another specific embodiment of the circuit board structure of the present invention from another viewing angle; Fig. 9 and Fig.10 The components shown are the same as those shown in the above figures, and for the sake of simplicity, their description will not be repeated here. The circuit board structure 30 further includes a primary dielectric layer 318, which is disposed below the second metal layer 306. The secondary dielectric layer 318 defines a clearance area 314, which is disposed below the slot 310 of the second metal layer 306 to avoid high-frequency signal coupling. The clearance area 314 can be greatly reduced; finally, the most suitable signal measurement circuit device is obtained under the conditions of multi-layer board integration, transmission performance, radiation leakage / coupling, etc.

[0057] Combined with the above features, the signal measurement circuit device 10 of the present invention has excellent transmission characteristics and is suitable for application in the structure of a multi-layer circuit board. Figure 7 , which is a cross-sectional view of the electric field vector of the ground plane of the present invention with a slot. The signal measurement circuit device 10 of the present invention retains most of the ground plane of the second metal layer 306, and the slot 310 is used to assist in mode conversion; Figure 7 As shown, the electric field of the present invention is relative to the electric field of the design without slots ( Figure 6 ), the signal strength of the electric field of the present invention increases on the side and above the middle signal line, while the signal strength of the electric field of the present invention decreases below the middle signal line, making it more compatible with the mode of the high-frequency probe 20.

[0058] The invention has the effect of reducing the loss of mode conversion to improve the accuracy of high-frequency measurement.

[0059] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A signal measurement circuit device, applied to a high-frequency probe, characterized in that: The signal measuring circuit device comprises: a circuit board structure; a multi-conductor transmission line segment formed by the circuit board structure; a high frequency measurement probe section, the high frequency measurement probe section being formed by the circuit board structure; and a conversion section, the conversion section is formed by the circuit board structure, the conversion section is disposed between the multi-conductor transmission line section and the high-frequency measurement probe section to connect to the multi-conductor transmission line section and the high-frequency measurement probe section, The circuit board structure includes: a first metal layer; a second metal layer; a dielectric layer disposed between the first metal layer and the second metal layer; and A plurality of vias connected to the first metal layer and the second metal layer, The high-frequency measurement probe point segment includes a group of high-frequency measurement probe points; the group of high-frequency measurement probe points are arranged on the first metal layer to contact the high-frequency probe to transmit a high-frequency signal; the second metal layer defines a slot; the slot is arranged corresponding to the high-frequency measurement probe point segment and the conversion segment to assist a mode conversion between the high-frequency probe and the multi-conductor transmission line segment.

2. The signal measuring circuit device according to claim 1, characterized in that: The circuit board structure is a multi-layer circuit board including at least three metal layers.

3. The signal measuring circuit device according to claim 1, characterized in that: The group of high frequency measurement probe points is a group of probe points arranged as ground-signal-ground.

4. The signal measuring circuit device according to claim 1, characterized in that: The multi-conductor transmission line segment is a grounded coplanar waveguide structure.

5. The signal measuring circuit device according to claim 1, characterized in that: The multi-conductor transmission line segment is a microstrip line structure.

6. The signal measuring circuit device according to claim 1, characterized in that: The slot has a width; if the width of the slot is closer to the multi-conductor transmission line segment, the width of the slot is narrower; if the width of the slot is closer to the high-frequency measurement probe segment, the width of the slot is wider.

7. The signal measuring circuit device according to claim 1, characterized in that: The slot is triangular.

8. The signal measuring circuit device according to claim 1, characterized in that: The high frequency measurement probe section includes a portion of the vias connected to the first metal layer and the second metal layer.

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