A phase shifter based on defective ground structure

Abstract

The present invention discloses a phase shifter based on a defective ground structure. The phase shifter includes a dielectric substrate, a defective ground structure, and a microstrip structure. The defective ground structure is disposed on one side of the dielectric substrate. The microstrip structure is disposed on a side of the dielectric substrate facing away from the defective ground structure. The microstrip structure is an edge-coupled structure. The microstrip structure and the defective ground structure jointly define the impedance matching of the defective ground structure at an operating frequency. Since the defective ground structure can change the distributed inductance and distributed capacitance of the microstrip line, it has a slow-wave effect, thereby enabling miniaturization of the phase shifter. At the same time, the microstrip structure forms an edge-coupled structure, which can optimize the impedance matching at the operating frequency, achieve a wider bandwidth range, and thus achieve good S parameters of the phase shifter.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a phase shifter based on a defective ground structure. Background Art

[0002] Phase shifters are key components in various microwave systems, primarily used in phase modulators, frequency upconverters, and phased arrays to achieve adaptive beamforming and steering. With the advancement of cellular technology and the application of multiple-input, multiple-output (MIMO) technology in communication systems, the size of phase shifters has become increasingly important.

[0003] Currently, many methods have been proposed to reduce the size of phase shifters, but these methods may affect the performance of the phase shifters.

[0004] However, there is an urgent need for a high-performance and miniaturized phase shifter. Summary of the Invention

[0005] The present application aims to provide a phase shifter based on a defective ground structure, which solves the problem that current phase shifters are difficult to achieve both miniaturization and high performance.

[0006] In a first aspect, the present application provides a phase shifter based on a defective ground structure, comprising:

[0007] dielectric substrate;

[0008] A defective ground structure is provided on one side of the dielectric substrate;

[0009] a microstrip structure, arranged on a side of the dielectric substrate away from the defective ground structure, and the microstrip structure is an edge-coupled structure;

[0010] The microstrip structure and the defective ground structure jointly define the impedance matching of the defective ground structure at the operating frequency.

[0011] In some embodiments of the present application, the microstrip structure includes a first microstrip line and a second microstrip line that are symmetrically arranged. The first microstrip line and the second microstrip line are both T-shaped structures, and the first microstrip line and the second microstrip line form an edge coupling structure.

[0012] In some embodiments of the present application, the first microstrip line includes a first sub-microstrip line and a second sub-microstrip line connected to each other, and the first sub-microstrip line and the second sub-microstrip line are perpendicular to each other; the second microstrip line includes a third sub-microstrip line and a fourth sub-microstrip line connected to each other, and the third sub-microstrip line and the fourth sub-microstrip line are perpendicular to each other;

[0013] The second sub-microstrip line and the third sub-microstrip line are arranged parallel to each other, and the second sub-microstrip line and the third sub-microstrip line are arranged at intervals, and the second sub-microstrip line and the third sub-microstrip line form an edge coupling structure; the first sub-microstrip line is arranged on the side of the second sub-microstrip line away from the third sub-microstrip line, and the fourth sub-microstrip line is arranged on the side of the third sub-microstrip line away from the second sub-microstrip line.

[0014] In some embodiments of the present application, the microstrip structure has a right pole, and the length of the second sub-microstrip line is inversely proportional to the frequency of the right pole; and / or the width of the third sub-microstrip line is inversely proportional to the frequency of the right pole.

[0015] In some embodiments of the present application, the dielectric substrate includes a grounding metal layer, which is disposed on a side of the dielectric substrate away from the upper metal layer. The grounding metal layer is etched to form the defective ground structure.

[0016] In some embodiments of the present application, recessed portions are provided on both sides of the defective ground structure, at least part of the recessed portions overlaps with the first sub-microstrip line and the fourth sub-microstrip line, and the width of the recessed portions is the same as the width of the first sub-microstrip line and / or the fourth sub-microstrip line.

[0017] In some embodiments of the present application, the recess has a bottom wall, and a first distance between the bottom walls of the recess on both sides is inversely proportional to the frequency of the right pole.

[0018] In some embodiments of the present application, the length of the defective ground structure along the first direction is inversely proportional to the frequency of the right pole; and / or the microstrip structure includes a left pole, and the length of the defective ground structure along the first direction is inversely proportional to the frequency of the right pole; wherein the first direction is the direction in which one of the two recessed portions points to the other.

[0019] In some embodiments of the present application, the recess has a sidewall, the defective ground structure has a first boundary parallel to the sidewall, and a second distance from the sidewall to the adjacent first boundary is inversely proportional to the frequency of the left pole and directly proportional to the frequency of the right pole.

[0020] The present application provides a phase shifter based on a defective ground structure, comprising a dielectric substrate, a defective ground structure, and a microstrip structure. The defective ground structure is disposed on one side of the dielectric substrate; the microstrip structure is disposed on a side of the dielectric substrate facing away from the defective ground structure, and the microstrip structure is an edge-coupled structure. The microstrip structure and the defective ground structure jointly define the impedance matching of the defective ground structure at an operating frequency. Because the defective ground structure can change the distributed inductance and distributed capacitance of the microstrip line, it exhibits a slow-wave effect, enabling miniaturization of the phase shifter. Furthermore, the microstrip structure forms an edge-coupled structure, which can optimize impedance matching at the operating frequency, achieve a wide bandwidth range, and thus achieve good S parameters for the phase shifter. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic structural diagram of a phase shifter provided in one embodiment of the present application;

[0023] Figure 2 A schematic structural diagram of a phase shifter provided in another embodiment of the present application;

[0024] Figure 3 A schematic structural diagram of a phase shifter provided in yet another embodiment of the present application;

[0025] Figure 4 A schematic structural diagram of a phase shifter provided in yet another embodiment of the present application;

[0026] Figure 5 A simulated phase response diagram of a phase shifter provided in one embodiment of the present application;

[0027] Figure 6 This is a simulated frequency response diagram of a phase shifter provided in one embodiment of the present application.

[0028] Specific element symbol description:

[0029] 100 - microstrip structure, 110 - first microstrip line, 111 - first sub-microstrip line, 112 - second sub-microstrip line, 120 - second microstrip line, 121 - third sub-microstrip line, 122 - fourth sub-microstrip line, 200 - defective ground structure, 210 - recessed portion, 300 - reference component. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention. In the description of the present invention, the meaning of "multiple" includes two or more, unless otherwise clearly and specifically defined.

[0031] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or illustration." Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the invention. In the following description, details are listed for the purpose of explanation. It should be understood that one of ordinary skill in the art may recognize that the invention can be implemented without these specific details. In other embodiments, known structures and processes are not elaborated in detail to avoid obscuring the description of the invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles disclosed herein.

[0032] It's important to note that common phase shifters include Schefman, broadside-coupled, load-line, and multimode resonator (MMR) types. Numerous methods have been proposed to reduce the size of phase shifters, such as the use of discrete components, most notably the construction of high-pass / low-pass networks. Furthermore, some research aims to minimize the size of phase shifters through rational structural layout. Furthermore, the use of novel technologies, such as MEMS RF phase shifters and liquid crystal dielectric layer phase shifters, is a new direction for miniaturization.

[0033] Defective ground structures have excellent passband and rejection characteristics and are often used in the design of advanced resonators, such as filters, power dividers, and baluns. However, they are less commonly used in phase shifter design, primarily due to the difficulty in achieving a good balance between frequency and phase response.

[0034] See also Figure 1 , Figure 1 A schematic structural diagram of a phase shifter provided in an embodiment of the present application is shown. This embodiment provides a phase shifter based on a defective ground structure 200, comprising: a dielectric substrate; the defective ground structure 200, disposed on one side of the dielectric substrate; and a microstrip structure 100, disposed on a side of the dielectric substrate facing away from the defective ground structure 200 and forming an edge coupling with the defective ground structure 200 along a direction perpendicular to the dielectric substrate. The microstrip structure 100 is used to determine the impedance matching of the defective ground structure 200 at the operating frequency.

[0035] It should be explained that since the defective ground structure 200 can change the distributed inductance and distributed capacitance of the microstrip line, it has a slow-wave effect and can achieve miniaturization of the phase shifter; at the same time, the microstrip structure 100 is an edge-coupled structure, which can determine the impedance matching of the defective ground structure at the operating frequency and achieve good S parameters of the phase shifter.

[0036] In some embodiments of the present application, the dielectric substrate includes an upper metal layer, and the microstrip structure 100 is formed on the upper metal layer.

[0037] In some embodiments of this application, please refer to Figure 2 The microstrip structure 100 includes a first microstrip line 110 and a second microstrip line 120 that are symmetrically arranged. The first microstrip line 110 and the second microstrip line 120 are both T-shaped structures, and the first microstrip line and the second microstrip line form an edge coupling structure.

[0038] In some embodiments of the present application, the first microstrip line 110 includes a first sub-microstrip line 111 and a second sub-microstrip line 112 connected to each other, and the first sub-microstrip line 111 and the second sub-microstrip line 112 are perpendicular to each other; the second microstrip line 120 includes a third sub-microstrip line 121 and a fourth sub-microstrip line 122 connected to each other, and the third sub-microstrip line 121 and the fourth sub-microstrip line 122 are perpendicular to each other;

[0039] In which, the second sub-microstrip line 112 and the third sub-microstrip line 121 are arranged parallel to each other, and the second sub-microstrip line 112 and the third sub-microstrip line 121 are spaced apart, and the second sub-microstrip line and the third sub-microstrip line form an edge coupling structure; the first sub-microstrip line 111 is arranged on the side of the second sub-microstrip line 112 away from the third sub-microstrip line 121, and the fourth sub-microstrip line 122 is arranged on the side of the third sub-microstrip line 121 away from the second sub-microstrip line 112.

[0040] In some embodiments of the present application, the microstrip structure 100 has a right pole, and the length of the second sub-microstrip line 112 is inversely proportional to the frequency of the right pole; and / or the width of the third sub-microstrip line 121 is inversely proportional to the frequency of the right pole.

[0041] In some embodiments of this application, please refer to Figure 3 The dielectric substrate includes a grounding metal layer, which is disposed on a side of the dielectric substrate away from the upper metal layer. The grounding metal layer is etched to form the defective ground structure 200. The defective ground structure 200 is a dumbbell-shaped structure.

[0042] In some embodiments of the present application, recessed portions 210 are provided on both sides of the defective ground structure 200 , at least part of the recessed portions 210 overlaps with the first sub-microstrip line 111 and the fourth sub-microstrip line 122 , and the width of the recessed portions 210 is the same as the width of the first sub-microstrip line 111 and / or the fourth sub-microstrip line 122 .

[0043] In some embodiments of the present application, the recessed portion 210 has a bottom wall, and a first distance between the bottom walls of the recessed portion 210 on both sides is inversely proportional to the frequency of the right pole.

[0044] In some embodiments of the present application, the length of the defective ground structure 200 along the first direction is inversely proportional to the frequency of the right pole; and / or the microstrip structure 100 includes a left pole, and the length of the defective ground structure 200 along the first direction is inversely proportional to the frequency of the right pole; wherein the first direction is the direction in which one of the two recessed portions 210 points to the other.

[0045] In some embodiments of the present application, the recessed portion 210 has a sidewall, the defective ground structure 200 has a first boundary parallel to the sidewall, and a second distance from the sidewall to the adjacent first boundary is inversely proportional to the frequency of the left pole and directly proportional to the frequency of the right pole.

[0046] In this embodiment, first, the DGS (defective ground structure 200) etches a defect pattern into the ground metal layer of the dielectric substrate, altering the distributed inductance and capacitance of the microstrip line, creating a slow-wave effect. This allows for miniaturization of the phase shifter. Second, the inherent passband and rejection characteristics of the DGS can lead to high insertion loss, low return loss, and a narrow bandwidth, resulting in poor performance. The edge-coupled microstrip structure 100 achieves impedance matching at a specific operating frequency, enabling the phase shifter to achieve good S-parameters.

[0047] The DGS circuit can be equivalent to a parallel inductor and capacitor, achieving phase shift and low-pass characteristics. Adding the edge-coupled microstrip structure 100 creates a series capacitor, achieving bandpass characteristics. By adjusting the structural parameters of the defective ground structure 200 and the edge-coupled microstrip structure 100, a fixed-phase phase shifter with a small relative size, low insertion loss, high phase shift accuracy, and wide bandwidth can be achieved within a frequency range with a predetermined center frequency.

[0048] It should be noted that the phase shifter includes a reference component 300 and a phase-shifting component. The phase of the phase shifter is the difference between the phase shift produced by the reference component 300 and the phase shift produced by the phase-shifting component. The dielectric substrate, the defective ground structure 200, and the microstrip structure 100 all constitute the phase-shifting component. The reference component 300 of the phase shifter can be of any type, including but not limited to a U-shaped microstrip line structure or a phase-shifting structure based on the defective ground structure 200. A phase shifter based on the defective ground structure 200 can achieve any fixed phase within a certain phase shift range. For example, a phase shifter with a 90° phase shift can achieve the following: relative dimensions of 0.164λ × 0.137λ, a relative bandwidth of 47%, an accuracy of ±1°, and an insertion loss of 0.9dB.

[0049] It should be noted that the fixed phase shift of the phase shifter in this embodiment is 90°, see Figure 4 The reference phase-shifting component is a U-shaped microstrip line structure. The dielectric substrate used is RO4003C, with a relative permittivity of 3.55 and a thickness of 0.8 mm. The input / output ports of the reference structure are located at both ends of the U-shaped microstrip line, while the input / output ports of the phase-shifting structure are located at the T-shaped ends of the edge-coupled microstrip structure 100. The termination impedance of both structures is 50 Ω.

[0050] Specifically, see Figure 2 The edge-coupled microstrip structure 100 is located on the upper metal layer and consists of two symmetrical T-shaped microstrip lines. The vertical width W2 of the T-shaped microstrip line is determined by the termination impedance, the relative dielectric constant of the dielectric substrate, and the substrate thickness. The horizontal length W1 of the T-shaped microstrip line is inversely proportional to the right pole frequency. The horizontal width L2 of the T-shaped microstrip line is inversely proportional to the right pole frequency.

[0051] Specifically, see Figure 3 The defective ground structure 200 is located in the lower metal layer and is a dumbbell-shaped structure. The width W4 of the central recess 210 minutes of the dumbbell-shaped structure is consistent with the width W2 of the vertical end of the T-shaped microstrip line. The spacing G2 between the central recess 210 minutes of the dumbbell-shaped structure is inversely proportional to the right pole frequency. The length L3 of the protruding portions at both ends of the dumbbell-shaped structure is inversely proportional to both the left and right pole frequencies. The width W3 of the protruding portions at both ends of the dumbbell-shaped structure is inversely proportional to the left pole frequency and directly proportional to the right pole frequency.

[0052] Specifically, see Figure 4 The width W6 of the microstrip line is determined by the termination impedance, the relative dielectric constant of the dielectric substrate, and the substrate thickness. The length L4 and width W5 of the U-shaped structure determine the characteristic impedance of the U-shaped microstrip structure 100, which is related to the fixed phase and frequency range.

[0053] The structural parameters of the 90° phase shifter based on the defective ground structure 200 are shown in Table 1 below:

[0054] L1 W1 G1 W2 L2 L3 W3 G2 W4 L4 W5 W6 (mm) 10 2.7 0.2 1.8 0.3 7.4 2.4 6.4 1.8 6 5.6 1.8

[0055] The simulated phase response and simulated frequency response of the 90° phase shifter based on the defective ground structure 200 are obtained through IE3D simulation. Figure 5 and Figure 6 The performance of the phase shifter is shown in Table 2 below:

[0056] Table 2

[0057] Center frequency Relative bandwidth Phase Accuracy Insertion loss size Relative size (λ×λ) f0=6.65GHz 47.4% (5.075-8.225GHz) 90° ±1° 0.89dB 7.4mm×6.2mm 0.164×0.137

[0058] In some embodiments (not shown), a metal layer is added below the defective ground structure 200 for packaging. A dielectric filler is placed between the defective ground structure 200 and the underlying metal layer, connected via metallized vias. The relative dielectric constant and thickness of the dielectric layer affect the phase shifter's performance.

[0059] In another embodiment, see Figure 1 , a metal layer can be added to the upper and lower layers of the defective ground structure 200 for packaging. There is dielectric filling between the edge-coupled microstrip structure 100 and the upper metal layer, and between the defective ground structure 200 and the lower metal layer. The upper metal, the defective ground structure 200, and the lower metal are all connected through metallized through-holes. The upper metal layer can use a coplanar waveguide (CPW) structure as a phase shifter port, and the coplanar waveguide is connected to the broadband coupled microstrip structure 100 through metallized through-holes. The relative dielectric constant and thickness of the dielectric layer have an impact on the phase shifter effect. In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the detailed description of other embodiments above, and will not be repeated here.

[0060] The basic concepts have been described above. It will be apparent to those skilled in the art that the detailed disclosure above is merely illustrative and does not limit the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to the present application. Such modifications, improvements, and amendments are suggested in the present application and remain within the spirit and scope of the exemplary embodiments of the present application.

[0061] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0062] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0063] Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may vary depending on the desired features of the individual embodiments. In some embodiments, numerical parameters should take into account the specified significant digits and adopt a general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values is as accurate as possible within the feasible range.

[0064] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this application is hereby incorporated by reference in its entirety, except for any application history that is inconsistent with or conflicts with this application, and any document (currently or subsequently appended to this application) that limits the broadest scope of the claims of this application. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent with or conflict with the content of this application, the descriptions, definitions, and / or terminology used in this application will control.

[0065] The above is a detailed introduction to the technical solutions provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A phase shifter based on a defective ground structure, characterized in that: include: dielectric substrate; A defective ground structure is provided on one side of the dielectric substrate; a microstrip structure, arranged on a side of the dielectric substrate away from the defective ground structure, and the microstrip structure is an edge-coupled structure; The microstrip structure and the defective ground structure jointly define the impedance matching of the defective ground structure at the operating frequency; The microstrip structure includes a first microstrip line and a second microstrip line that are symmetrically arranged with each other, the first microstrip line and the second microstrip line are both T-shaped structures, and the first microstrip line and the second microstrip line form an edge coupling structure; The first microstrip line includes a first sub-microstrip line and a second sub-microstrip line connected to each other, and the first sub-microstrip line and the second sub-microstrip line are perpendicular to each other; the second microstrip line includes a third sub-microstrip line and a fourth sub-microstrip line connected to each other, and the third sub-microstrip line and the fourth sub-microstrip line are perpendicular to each other; The second sub-microstrip line and the third sub-microstrip line are arranged parallel to each other, and the second sub-microstrip line and the third sub-microstrip line are arranged at intervals, and the second sub-microstrip line and the third sub-microstrip line form an edge coupling structure; the first sub-microstrip line is arranged on a side of the second sub-microstrip line away from the third sub-microstrip line, and the fourth sub-microstrip line is arranged on a side of the third sub-microstrip line away from the second sub-microstrip line; The microstrip structure has a right pole, the length of the second sub-microstrip line is inversely proportional to the frequency of the right pole; the width of the third sub-microstrip line is inversely proportional to the frequency of the right pole; Recesses are provided on both sides of the defective ground structure, at least a portion of the recesses overlaps with the first sub-microstrip line and the fourth sub-microstrip line, and a width of the recesses is the same as a width of the first sub-microstrip line and / or the fourth sub-microstrip line; The recessed portion has a bottom wall, and a first distance between the bottom walls of the recessed portions at both sides is inversely proportional to the frequency of the right pole.

2. The phase shifter based on defective ground structure according to claim 1, characterized in that: The dielectric substrate comprises a grounding metal layer, which is arranged on a side of the dielectric substrate away from the upper metal layer. The grounding metal layer is etched to form the defective ground structure.

3. The phase shifter based on defective ground structure according to claim 2, characterized in that: The length of the defective ground structure along the first direction is inversely proportional to the frequency of the right pole; the microstrip structure includes a left pole, and the length of the defective ground structure along the first direction is inversely proportional to the frequency of the right pole; wherein the first direction is the direction in which one of the two recessed portions points to the other.

4. The phase shifter based on defective ground structure according to claim 3, characterized in that: The recess has a sidewall, the defective ground structure has a first boundary parallel to the sidewall, and a second distance from the sidewall to the adjacent first boundary is inversely proportional to the frequency of the left pole and directly proportional to the frequency of the right pole.

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