Microstrip low-speed wave transmission line using ground shield of zigzag pattern and branch line coupler using same

Abstract

The present invention relates to a transmission line including a zigzag pattern ground shield structure. The transmission line includes a plurality of rectangular unit ground units including a first metal pattern and a second metal pattern arranged on two different layers, wherein each of the first metal pattern and the second metal pattern is bent in an L shape and symmetrically arranged at positions facing each other on the basis of an XY plane, and the unit ground units are periodically repeated in X-axis and Y-axis directions to form a diagonal zigzag pattern.

Description

Microstrip low-speed transmission line using a zigzag pattern ground shield and branch line coupler using the same

[0001] The present invention relates to a microstrip-based low-speed transmission line (SWTL) using a ground shield in a zigzag pattern, and more particularly, to a low-speed transmission line that reduces the area of ​​a high-frequency circuit and can be applied without performance degradation even in curved and branched structures.

[0002] The following explanations are intended to assist in understanding the technical significance of the invention and do not presuppose prior public disclosure. Therefore, even if they are included in the background technology of the invention, they should not be considered publicly known technology in and of themselves.

[0003] The recent trend toward miniaturization and increased integration of circuits has highlighted the need for slow-wave transmission lines (SWTLs), which can reduce the physical length of transmission lines while maintaining the same electrical characteristics. Slow-wave (SW) technology is an effective technology that can implement the same circuit performance within a shorter physical length by lowering the phase velocity of the signal without changing the characteristic impedance of the transmission line, thereby reducing the effective wavelength. Typically, microstrip (MS)-based transmission lines utilize a ground shield with slots periodically formed perpendicular to the direction of propagation in the ground plane beneath the signal line to implement these slow-wave characteristics. This slotted ground shield blocks the path of the image current flowing within the ground plane, increasing the inductance and capacitance per unit length, thereby achieving a shortened wavelength. However, since the existing slot-type ground shield must be arranged in a form that extends on both sides compared to the width of the microstrip signal line due to the structural characteristics, a large area is required for sufficient signal insulation. This makes the existing slot-type structure difficult to practically apply to applications that require various path designs, such as bending or junction. In particular, when the path changes at a 90-degree angle, a separate transition part must be inserted to connect two low-speed transmission lines, which causes the circuit design and manufacturing process to be complicated, such as recalculating the electrical length between lines and adjusting the design. Therefore, a new low-speed transmission line structure with excellent efficiency and area saving effect is required in various application environments by improving the structural limitations and design complexity of existing low-speed transmission lines.

[0004] The present invention aims to provide a microstrip-based low-speed transmission line using a ground shield in a zigzag pattern.

[0005] In addition, the present invention aims to provide a low-speed transmission line that can be connected naturally and efficiently without a separate transition section or additional electrical length correction process even in a curved or branched structure.

[0006] However, the technical problems to be solved by the present invention are not limited to the technical problems described above, and other technical problems may exist.

[0007] A transmission line including a zigzag pattern ground shield structure according to one embodiment of the present invention includes a plurality of rectangular unit grounding units including a first metal pattern and a second metal pattern arranged in two different layers, wherein the first metal pattern and the second metal pattern are each bent into an L shape and symmetrically arranged at facing positions based on the XY plane, and the unit grounding units can be periodically repeated in the X-axis and Y-axis directions to form a diagonal zigzag pattern.

[0008] According to one embodiment, the first metal pattern and the second metal pattern may be formed spaced apart from each other in the Z-axis direction without being electrically connected to each other.

[0009] According to one embodiment, the rectangular unit grounding units may have a size of 4×2.

[0010] According to one embodiment, the width of the first metal pattern and the width of the second metal pattern may be the same.

[0011] According to one embodiment, a dielectric having a predetermined permittivity may be interposed between the zigzag pattern ground shield and the transmission line.

[0012] A branch line coupler including a zigzag pattern ground shield structure according to another embodiment of the present invention includes a first port, a second port, a third port, and a fourth port, a first branch line electrically connecting the first port and the fourth port, a second branch line electrically connecting the first port and the second port, a third branch line electrically connecting the second port and the third port, and a fourth branch line electrically connecting the third port and the fourth port, wherein the first branch line, the second branch line, the third branch line, and the fourth branch line can have an electrical length that is 1 / 4 wavelength at a center frequency, the first branch line and the third branch line can have a first characteristic impedance, and the second branch line and the fourth branch line can have a second characteristic impedance.

[0013] Here, the zigzag pattern grounding shield structure includes a plurality of rectangular unit grounding units including a first metal pattern and a second metal pattern arranged in two different layers, and the first metal pattern and the second metal pattern can be each bent into an L shape and symmetrically arranged at facing positions based on the XY plane, and the unit grounding units can be periodically repeated in the X-axis and Y-axis directions to form a diagonal zigzag pattern.

[0014] According to one embodiment, the zigzag pattern ground shield is characterized in that it is arranged at the intersection of the first branch line, the second branch line, the third branch line, and the fourth branch line.

[0015] According to the present invention, the limitations of the 90-degree structural design of the conventional slot-type ground shield can be fundamentally resolved, while maintaining the electromagnetic performance and design advantages provided by the conventional structure.

[0016] In addition, according to the present invention, since the grounding units are arranged in a rectangular shape and aligned without diagonal lines, they can be freely arranged in any position without interference with the existing circuit layout, and the layout procedure can be simplified through simple duplication of the units.

[0017] In addition, according to the present invention, it is possible to effectively block the image current flow in the X-axis and Y-axis directions in a Cartesian coordinate system.

[0018] However, the effects according to the present invention are not limited to the effects described above, and other effects may exist.

[0019] Fig. 1 is a drawing showing the planar structure of a slot-type ground shield (100) according to a comparative example.

[0020] FIG. 2 is a drawing illustrating an image current blocking mechanism when a signal current flows in the X-axis direction or the Y-axis direction in a slot-type ground shield structure according to a comparative example.

[0021] FIG. 3 is a drawing showing a planar structure of a ground shield according to one embodiment of the present invention.

[0022] FIG. 4 is a drawing illustrating an image current blocking mechanism generated by a ground shield structure according to one embodiment of the present invention.

[0023] Figure 5 is a drawing showing the analysis per unit length of SWTL according to a comparative example.

[0024] Figure 6 is a drawing showing the analysis per unit length of SWTL according to the present invention.

[0025] FIG. 7 is a graph showing simulation results for the wavelength (λ) and attenuation constant (α) of a general microstrip transmission line having a characteristic impedance of 35 Ω at a frequency of interest of 150 GHz, a low-speed microstrip transmission line of a comparative example, and a low-speed microstrip transmission line according to the present invention.

[0026] Fig. 8 is a drawing showing a low-speed wave branch line coupler based on a comparative example.

[0027] Fig. 9 is a drawing showing a low-speed wave branch line coupler using the structure proposed in the present invention.

[0028] Fig. 10 is a graph showing the S-parameter simulation results of a low-speed branch line coupler implemented based on a slot-type ground shield of a comparative example.

[0029] Fig. 11 is a graph showing the S-parameter simulation results of SW BLC using the zigzag ground shield proposed in the present invention.

[0030] Figure 12 is a drawing comparing the physical areas of three branch line couplers designed based on a center frequency of 150 GHz.

[0031] Below, with reference to the attached drawings, embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. The present invention is susceptible to various modifications and embodiments, and specific embodiments are illustrated in the drawings and specifically described in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

[0032] To clearly explain the present invention, parts irrelevant to the description have been omitted from the drawings, and similar parts have been designated with similar drawing reference numerals throughout the specification. In addition, when describing with reference to the drawings, even if components are indicated by the same name, the drawing numbers may vary depending on the drawing. The drawing numbers are described merely for the convenience of explanation, and the concept, feature, function, or effect of each component is not limited by the drawing numbers.

[0033] In describing each drawing, similar reference numerals are used to refer to similar components. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another. For example, a first component could be referred to as a second component, and similarly, a second component could also be referred to as a first component, without departing from the scope of the present invention. As used herein, expressions such as “A or B,” “at least one of A and / or B,” or “one or more of A and / or B” can encompass all possible combinations of the listed items. For example, expressions such as “A or B,” “at least one of A and B,” or “at least one of A or B” can all refer to cases where (1) at least one A is included, (2) at least one B is included, or (3) both at least one A and at least one B is included.

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0035] Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this application.

[0036] Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element in between. Furthermore, when a part is said to "include" a component, this should be understood to mean that it may include other components rather than excluding other components unless specifically stated to the contrary, and does not preclude the presence or possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0037] Transmission lines are distributed parameter circuits, and it can be considered that there is no change in the overall result even if the entire transmission line is divided into very small unit lengths (segments) and each segment is analyzed independently. This is because when the transmission line operates at high frequencies, the distribution of voltage and current has the characteristic of continuously and uniformly changing along the line length, and the analysis and design of the transmission line can be performed based on this characteristic. When it is assumed that there is no loss in the transmission line (lossless TL), the characteristic impedance is a representative variable representing the characteristics of the transmission line. can be calculated by . Also, the phase velocity v, which represents the speed at which a signal propagates in a transmission line, p uses the same inductance and capacitance. can be expressed as . Therefore, the wavelength of the transmission line (TL) , where f represents the frequency of interest. From this equation, by increasing L and C in the same proportion, the wavelength λ can be reduced while maintaining the characteristic impedance Z0.

[0038] Typically, in microstrip-based transmission lines, the ground plane is placed very close to the signal line to increase the capacitance per unit length, and the signal line is designed to be narrow to increase the inductance per unit length. However, when the ground plane is placed very close to the signal line in this way, the image current induced in the ground plane by the signal line current can easily flow, and this image current can act in the direction of reducing the inductance value per unit length. Therefore, to effectively achieve the desired level of inductance and capacitance, an additional structure that can suppress or minimize the generation of this image current is required. To this end, a method that artificially blocks the flow of image current by introducing a patterned ground shield can be used.

[0039] FIG. 1 is a drawing showing a top view structure of a slot-type ground shield (100) according to a comparative example. The slot-type ground shield (100) includes a first ground layer (111) composed of a plurality of first metal conductors, and a second ground layer (112) composed of a plurality of second metal conductors arranged to be spaced apart from the first ground layer (111) in the Z-axis direction. The first ground layer (111) and the second ground layer (112) may be alternately arranged so as not to overlap each other, but may be arranged with a space between them based on the XY plane. Here, the first ground layer (111) and the second ground layer (112) may not be a single metal layer arranged on the same plane, but may be independently formed on different layers in the Z-axis direction. The first ground layer (111) and the second ground layer (112) are physically separated but are arranged very close together, so the difference in distance from the signal line to each ground layer (111, 112) can be set to a negligible level.

[0040] As illustrated in Fig. 1, the spacing between slots and adjacent slots within the ground layers (111, 112) is designed to be the same, and this spacing can be defined as Ws. Specifically, since both the spacing between two adjacent slots existing on the same metal layer and the width of the slot itself are set to Ws, the two metal layers can be configured to operate as a uniform ground plane by intersecting each other.

[0041] Due to these structural characteristics, per-unit length analysis, which analyzes the characteristics per unit length along the longitudinal direction of the transmission line, can be reliably performed. In particular, since the image current existing on the ground plane is formed along the metal region between the slots through its flow path, the slot spacing Ws has a direct correlation with the intensity of the image current. In other words, the larger Ws is, the greater the amount of image current that can flow along the ground plane. Therefore, to minimize this, Ws should be set as small as possible.

[0042] In addition, in order for boundary conditions to be clearly defined during electromagnetic simulation, the first ground layer (111) and the second ground layer (112) must be electrically connected at both ends of the slot, and such connection can also be advantageous in terms of improving insulation performance with the silicon substrate.

[0043] FIG. 2 is a drawing showing an image current blocking mechanism when a signal current flows in the X-axis direction or the Y-axis direction in a slot-type ground shield (100) structure according to a comparative example, and also includes a structure when two low-speed transmission lines (SWTL) meet at a 90-degree angle.

[0044] Referring to Fig. 2, we would like to explain how a slot-type ground shield structure according to a comparative example operates in a curved connection situation. As illustrated in Fig. 2, when a signal current (130) flows in a specific direction in a transmission line (120), a corresponding zero-phase current (140) is induced and flows in the opposite direction in the ground plane. At this time, slot structures (111, 112) periodically arranged on the ground plane can reduce the negative magnetic coupling effect by artificially interrupting the continuous flow of the zero-phase current (140). Magnetic coupling is a phenomenon in which magnetic fluxes interfere with each other between adjacent conductors or circuit paths, causing electromagnetic interference (EMI), which can result in waveform distortion or signal loss in high-frequency circuits. Accordingly, by blocking the displacement current of the zero-phase current (140) in the ground plane, it is possible to prevent the magnetic flux generated from the signal current from spreading outward.

[0045] However, the slot-type ground shield (100) structure of Fig. 2 has structural limitations, and in particular, since the ground plane is configured to be greatly expanded on both sides compared to the width of the microstrip transmission line, the area occupied by the entire structure can become very large. Since the ground shield must sufficiently electromagnetically block the signal line from the silicon substrate, it cannot be designed to be limited to simply within the projection area of ​​the signal line, and a ground structure that extends on both sides is essential.

[0046] This allows for a consistent design in straight line sections, but makes it difficult to maintain continuous slot connections in sections where the transmission line curves or bends at 90 degrees. In particular, when 90-degree connections are required, the slot structure cannot follow the curve and breaks, requiring a cumbersome structure that requires a separate transition part between the two SWTLs. This transition part inevitably causes discontinuity and can degrade signal quality.

[0047] In addition, the addition of a transition section requires recalculation and compensation of the electrical length of the entire transmission line, which can lead to increased design time and complicated circuit analysis. Therefore, the SWTL structure based on the slot-type ground shield (100) of Fig. 2 is not suitable for designs aimed at circuit miniaturization, and has limitations in that it is difficult to flexibly respond to various path configurations.

[0048] To solve these problems, the present invention proposes a new type of ground shield structure capable of accommodating wave propagation in both the X-axis and Y-axis directions in a Cartesian coordinate system.

[0049] FIG. 3 is a drawing showing a planar structure of a ground shield (200) according to one embodiment of the present invention.

[0050] Referring to FIG. 3, the ground shield (200) is composed of a plurality of rectangular unit grounding units (210) having a size of 4×2, rather than a one-way straight pattern. Each unit grounding unit (210) is composed of two metal patterns (211a, 212a), which are arranged on two different layers, each bent in an L shape, and arranged at positions facing each other when viewed from a plane. That is, each unit (210) is stacked while maintaining an alignment state in the vertical direction, and the subsequent unit is arranged at the outer edge of the preceding unit in the horizontal direction. This arrangement method results in the formation of a diagonal zigzag pattern that is periodically repeated along the entire XY plane, and when viewed from the XY plane, the first grounding layer (211) and the second grounding layer (212) are alternately repeated.

[0051] This configuration utilizing a rectangular-shaped unit grounding unit (210) can structurally solve the problem of impossible curved connection and structural disconnection when changing direction that occurred in the slot-type grounding structure of the comparative example. In particular, since each unit is arranged at a regular interval and forms a cross-symmetrical shape with respect to each other, the path of the image current within the grounding layer can be effectively controlled in both the X-axis and Y-axis directions, and as a result, the same electromagnetic shielding performance can be maintained regardless of the direction of wave propagation.

[0052] In addition, since this structure is in the form of a unit grounding unit (210) being repeatedly arranged, repeatability of design and layout is secured, and a high degree of design flexibility can be secured compared to existing structures in that a continuous and consistent grounding configuration can be maintained even when the transmission line is curved or branched in various directions.

[0053] FIG. 4 is a drawing illustrating an image current blocking mechanism generated by a ground shield (200) structure according to one embodiment of the present invention, based on a case where an image current (240) is induced in the opposite direction, counterclockwise, on a ground plane when a signal current (230) flows clockwise.

[0054] FIG. 4 can effectively block the continuous movement path of the image current (240) by forming a grid-shaped gap that is cross-distributed along both the X-axis and Y-axis of the XY coordinate system. Since this gap impedes the flow of the image current (240) not only in the linear direction but also in the diagonal direction, regardless of the direction in which the signal current (230) flows, the corresponding image current (240) can be completely suppressed or distorted within the ground plane, thereby reducing electromagnetic interference.

[0055] In particular, the slot-type ground shield (100) of the comparative example maximizes the image current suppression effect only when the propagation direction is vertical or horizontal, whereas the zigzag-type ground structure of the present invention forms a symmetrical and periodic gap structure with respect to both the X-axis and the Y-axis, and thus has the characteristic of being able to suppress the image current regardless of the direction of the transmission line (220).

[0056] FIG. 5 is a drawing showing an analysis per unit length of SWTL according to a comparative example, and FIG. 6 is a drawing showing an analysis per unit length of SWTL according to the present invention.

[0057] Figures 5 and 6 show the per unit length analysis for two low-speed microstrip transmission lines (MS SWTL) having the same microstrip line dimensions but different ground shield configurations, when a dielectric medium having a depth h intersects. In the latter case, since the ground shield is configured with the same density as before, the per unit length analysis results along the transmission line (120) can be maintained without change. In addition, as can be seen in Figure 6, under the same consideration volume (150), Assuming that, both structures can provide similar capacitance and inductance values ​​per unit length. Therefore, it can be expected that the two structures will also show the same results in wavelength reduction characteristics.

[0058] Fig. 7 is a graph showing the simulation results for the wavelength (λ) and attenuation constant (α) of a regular microstrip transmission line (regular MS TL) having a characteristic impedance of 35Ω at a frequency of interest of 150 GHz, a low-speed microstrip transmission line of a comparative example (conventional MS SWTL), and a low-speed microstrip transmission line according to the present invention (proposed MS SWTL). Here, Fig. 7(a) is a graph comparing the wavelengths (λ) of three structures, and Fig. 7(b) is a graph comparing the attenuation constants (α) of the same structures.

[0059] As can be seen in Fig. 7(a), while a typical MS transmission line exhibits a wavelength (λ) of about 1034 μm at 150 GHz, both the MS SWTL of the comparative example and the MS SWTL of the present invention exhibit a shorter wavelength of about 500 μm. This is a result reflecting the typical wavelength shortening characteristic of a low-speed wave structure, and suggests that the structure of the comparative example and the structure of the present invention induce similar phase velocities by forming similar capacitances and inductances per unit length. Since both the structure of the comparative example and the structure of the present invention maintain the same wavelength level, it indicates that the proposed structure can provide sufficient performance as a structural solution for reducing the electrical length of a transmission line.

[0060] Fig. 7(b) shows the results of comparing the attenuation constant (α) under the same conditions. While the α of the general MS TL remains constant at about 1.05 dB / mm, the MS SWTL of the comparative example and the MS SWTL of the present invention are in the range of 1.3 to 1.6 dB / mm, respectively, and the α value also shows a tendency to gradually increase as the frequency increases. This is because the electrostatic field between the signal line and the ground plane is more strongly concentrated in the low-speed wave structure, which increases the conductor and dielectric loss. However, despite this increase in the attenuation constant, when compared based on the same electrical length as a result of the wavelength being shortened by about twice, the insertion loss may actually be lower than that of the general structure.

[0061] FIG. 8 is a drawing showing a low-speed wave branch line coupler (300) based on a comparative example, and FIG. 9 is a drawing showing a low-speed wave branch line coupler (400) applying the structure proposed in the present invention.

[0062] The low-speed transmission line (SWTL) according to the present invention can be applied to various passive components.

[0063] Typically, a branch line coupler (300) is composed of four transmission line branches (310, 320, 330, 340) each having an electrical length of λ / 4, which are arranged perpendicularly to each other to form four T-junctions. Among these four transmission lines (310, 320, 330, 340), two (310, 330) that are parallel to each other have a characteristic impedance Z0 (Ω), and the remaining two (320, 340) have a characteristic impedance of Z0 / 2 (Ω). Generally, Z0 is set to 50Ω for design convenience. A branch line coupler that is miniaturized based on the SWTL structure is called a slow wave branch line coupler (SW BLC).

[0064] As previously explained, since the microstrip-based SWTL structure of the comparative example is not suitable for a structure that is bent in a right-angled direction, in the SW BLC, a switching section (311, 321, 331, 341) is arranged at each of the four T-junctions to connect four SWTLs (310, 320, 330, 340). As a result, the λ / 4 length is divided into three separate sections, with the SWTL arranged only in the central section and the two ends consisting of general transmission lines. Therefore, precise calculation is essential to redistribute the length of each section and to minimize performance degradation due to discontinuity that occurs during the switching process.

[0065] On the other hand, in the SW BLC structure (400) according to the present invention, ground shield switching parts (411, 421, 431, 441) in a zigzag pattern are sequentially arranged at each intersection point, so that the connection between SWTLs is smoothly achieved without a separate switching part.

[0066]

[0067] Table 1 above summarizes the signal line widths used in the design of regular transmission lines (TL) and slow-wave transmission lines (SWTL) with characteristic impedances of 35 Ω and 50 Ω, respectively. Table 1 specifically shows how the signal line width is adjusted according to the impedance value in a microstrip-based transmission line structure, and allows for a comparison of the geometric differences between the two structures designed to have the same electrical impedance. For regular transmission lines, the signal line width is set to 12 μm to implement 35 Ω impedance, and the signal line width for 50 Ω impedance is designed to be 5 μm. On the other hand, for slow-wave transmission lines with the same impedance, narrower signal line widths of 7.5 μm (35 Ω) and 3 μm (50 Ω) are used, respectively. This is because, due to the characteristics of the slow wave structure, the signal line width must be designed narrower to increase the inductance (L) per unit length, and at the same time, the capacitance (C) must also be increased through the ground shield structure to implement the wavelength shortening effect.

[0068] The figures in Table 1 demonstrate that SWTL design is not simply a replacement for existing structures; rather, it can simultaneously improve transmission characteristics and area efficiency by optimizing signal line widths and grounding structures. Furthermore, Table 1 can serve as quantitative evidence for how SWTL can be applied in high-frequency circuit designs that require implementation of various characteristic impedances.

[0069] Fig. 10 is a graph showing the S-parameter simulation results of a low-speed branch line coupler (SW BLC) implemented based on a slot-type grounding shield of a comparative example, and Fig. 11 is a graph showing the S-parameter simulation results of a SW BLC (proposed SW BLC) to which a zigzag-type grounding shield proposed in the present invention is applied.

[0070] At a center frequency of 150 GHz, both structures measure insertion loss to be approximately -3.6 dB for S12 and approximately -4 dB for S13, which are close to the ideal -3 dB shunt coupler characteristic. The reflection coefficient S11 is below -22 dB, demonstrating excellent matching characteristics, and S14 is below -15 dB, confirming that the isolation characteristics of port 4 are maintained. The phase difference represents the signal phase difference between ports 2 and 3, and is shown to maintain a very stable phase difference of 90° ± 0.3° over the frequency range from 140 GHz to 160 GHz.

[0071] In particular, the results of the proposed structure shown in Fig. 11 show that the amplitude error is less than 0.45 dB and the phase error is also maintained very precisely at less than 0.3° when compared to the structure of the comparative example. This suggests that the structure of the present invention can achieve performance equivalent to the low-speed wave structure of the comparative example while minimizing insertion loss or phase fluctuation, and demonstrates that it is a structure that can effectively perform the precise phase control and power distribution functions required in high-frequency integrated circuits.

[0072] Fig. 12 is a drawing comparing the physical areas of three branch line couplers designed based on a center frequency of 150 GHz: a general BLC (510), a low-speed BLC (520) of a comparative example, and a low-speed BLC (530) according to the present invention. Fig. 12 clearly shows the external dimensions of each structure, and is diagrammatically arranged in an overlapping manner so that the area differences between the structures can be visually compared.

[0073] The general BLC (510) has a size of 264 μm × 270 μm, is the structure that occupies the largest area, and is a standard circuit configuration to which a low-speed transmission line (SWTL) is not applied. The SW BLC (520) of the comparative example applies a slot-type ground shield, and since a transition part must be added due to structural constraints, it occupies an area of ​​164 μm × 118.5 μm. On the other hand, the SW BLC (530) to which the zigzag-type ground shield proposed in the present invention is applied can be designed with a smaller area of ​​148 μm × 107 μm by removing an unnecessary transition part and continuously configuring the transmission line.

[0074] In terms of area, the proposed structure occupies approximately 80% of the area of ​​conventional structures, and less than 25% of the total area of ​​a standard BLC. This area reduction is a crucial advantage in high-frequency integrated circuits, enabling the same functionality in a more compact structure, thereby enabling high-density deployment, multi-channel integration, and improved power efficiency.

[0075] Although the embodiments described above have been described by way of limited examples and drawings, those skilled in the art will appreciate that various modifications and variations can be made based on the above teachings. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0076] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

[0077] [Explanation of symbols]

[0078] 100: Slotted ground shield

[0079] 111: First ground layer

[0080] 112: Second ground layer

[0081] 120: Transmission line

[0082] 130, 230: signal current

[0083] 140, 240: Image current

[0084] 200: Zigzag pattern ground shield

[0085] 210: Unit Grounding Unit

[0086] 211: First metal pattern

[0087] 212: Second metal pattern

[0088] 300, 400: Low-speed branch line coupler

[0089] 310, 320, 330, 340, 410, 420, 430, 440: Transmission line branches

[0090] 311, 321, 331, 341: Transition section

[0091] 411, 421, 431, 441: Zigzag pattern transition

Claims

1. In a transmission line including a zigzag pattern ground shield structure, The above zigzag pattern ground shield structure is, Comprising a plurality of rectangular unit grounding units including a first metal pattern and a second metal pattern arranged on two different layers, The first metal pattern and the second metal pattern are each bent into an L shape and symmetrically arranged at facing positions based on the XY plane. A transmission line including a zigzag pattern grounding shield structure, wherein the above-mentioned unit grounding units are periodically repeated in the X-axis and Y-axis directions to form a diagonal zigzag pattern.

2. In paragraph 1, A transmission line including a zigzag pattern ground shield structure, characterized in that the first metal pattern and the second metal pattern are not electrically connected to each other and are formed spaced apart in the Z-axis direction.

3. In paragraph 1, A transmission line including a zigzag pattern grounding shield structure, characterized in that the above rectangular unit grounding units have a size of 4×2.

4. In paragraph 1, A transmission line including a zigzag pattern shield structure, characterized in that the width of the first metal pattern and the width of the second metal pattern are the same.

5. In paragraph 1, A transmission line including a zigzag pattern shield structure, characterized in that a dielectric having a predetermined permittivity is interposed between the zigzag pattern ground shield and the transmission line.

6. In a branch line coupler including a zigzag pattern ground shield structure, Port 1, Port 2, Port 3 and Port 4; A first branch line electrically connecting the first port and the fourth port; A second branch line electrically connecting the first port and the second port; A third branch line electrically connecting the second port and the third port; Including a fourth branch line electrically connecting the third port and the fourth port, The first branch line, the second branch line, the third branch line, and the fourth branch line have an electrical length that is 1 / 4 wavelength at the center frequency, The first branch line and the third branch line have a first characteristic impedance, The second branch line and the fourth branch line have a second characteristic impedance different from the first characteristic impedance, The above zigzag pattern ground shield structure is, Comprising a plurality of rectangular unit grounding units including a first metal pattern and a second metal pattern arranged on two different layers, The first metal pattern and the second metal pattern are each bent into an L shape and symmetrically arranged at facing positions based on the XY plane. A branch line coupler characterized in that the above unit grounding units are periodically repeated in the X-axis and Y-axis directions to form a diagonal zigzag pattern.

7. In paragraph 6, A branch line coupler, characterized in that the first metal pattern and the second metal pattern are not electrically connected to each other and are formed spaced apart in the Z-axis direction.

8. In paragraph 6, A branch line coupler comprising a zigzag pattern grounding shield structure, wherein the above rectangular unit grounding units have a size of 4×2.

9. In paragraph 6, A branch line coupler including a zigzag pattern shield structure, characterized in that the width of the first metal pattern and the width of the second metal pattern are the same.

10. In paragraph 6, A branch line coupler characterized in that a dielectric having a predetermined permittivity is interposed between the zigzag pattern ground shield and the transmission line.

11. In paragraph 6, A branch line coupler, characterized in that the zigzag pattern ground shield is disposed at the intersection of the first branch line, the second branch line, the third branch line, and the fourth branch line.

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