Embedded microstrip filter, manufacturing method thereof, power amplifier and electronic equipment

Abstract

The invention provides an embedded microstrip filter, a manufacturing method thereof, a power amplifier comprising the embedded microstrip filter and electronic equipment. The embedded microstrip filter comprises: a microstrip transmission line; the filter structure is embedded in the micro-strip transmission line, the filter structure comprises at least one row of multiple island-shaped metal patches and multiple capacitors or inductance elements, and the multiple metal patches are connected with the micro-strip transmission line through the multiple capacitors or inductance elements. According to the embedded microstrip filter provided by the invention, the filtering function can be realized under the condition of not occupying extra space.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, in particular to an embedded microstrip filter, a manufacturing method thereof, a power amplifier comprising the embedded microstrip filter, and an electronic device. BACKGROUND

[0002] A dual-frequency or even triple-frequency power amplifier (PA) needs to support the transmission of multiple frequency band signals at the same time. The concurrency of multiple frequency signals makes the spectrum components more complex, and in addition to the influence of harmonics, there are also out-of-band intermodulation components, which have a great influence on the performance of the PA.

[0003] A microstrip line-based filtering structure can be used to suppress out-of-band intermodulation. The filtering structure for the PA in the related art mainly has two ways of series connection and parallel connection. However, both the series connection and the parallel connection will occupy extra space outside the output matching network of the PA, which is difficult to realize in the case of tight layout space on the circuit board. SUMMARY

[0004] The main purpose of the embodiments of the present application is to propose an embedded microstrip filter, a manufacturing method thereof, a power amplifier, and an electronic device, which aims to realize the filtering function without occupying extra space.

[0005] The embodiments of the present application provide an embedded microstrip filter, comprising: a microstrip transmission line; and a filtering structure embedded in the microstrip transmission line, wherein the filtering structure comprises at least one column of multiple island-shaped metal patches, and multiple capacitive or inductive elements connecting the multiple metal patches with the microstrip transmission line.

[0006] In some embodiments, the multiple metal patches are arranged in a matrix, and the multiple capacitive or inductive elements connect two metal patches in two adjacent columns with each other.

[0007] In some embodiments, the multiple capacitive or inductive elements are surface-mounted lumped elements.

[0008] In some embodiments, the multiple capacitive or inductive elements are distributed elements.

[0009] In some embodiments, the distributed elements include a coil inductance or an interdigital capacitance.

[0010] In some embodiments, the embedded microstrip filter further comprises a substrate and a metal ground, wherein the microstrip transmission line and the filtering structure are arranged on the top surface of the substrate, and the metal ground is arranged on the bottom surface of the substrate.

[0011] The embodiment of the present application also provides a method for manufacturing an embedded microstrip filter, comprising: forming a microstrip transmission line on a top surface of a substrate; etching the microstrip transmission line to form a rectangular gap, wherein at least one column of a plurality of island-shaped metal patches is reserved in the rectangular gap; and forming a plurality of capacitive or inductive elements on the substrate, wherein the plurality of capacitive or inductive elements connects the plurality of metal patches and the microstrip transmission line.

[0012] In some embodiments, the plurality of metal patches are arranged in a matrix, and the plurality of capacitive or inductive elements connects two metal patches in two adjacent columns to each other.

[0013] In some embodiments, the plurality of capacitive or inductive elements are surface mount lumped elements, and forming the plurality of capacitive or inductive elements on the substrate comprises: welding surface mount lumped elements on the substrate, so that the plurality of capacitive or inductive elements connects the plurality of metal patches and the microstrip transmission line.

[0014] In some embodiments, the plurality of capacitive or inductive elements are distributed elements, and forming the plurality of capacitive or inductive elements on the substrate comprises: forming the plurality of capacitive or inductive elements on the substrate by etching the microstrip transmission line.

[0015] In some embodiments, the distributed elements comprise coil inductors or interdigital capacitors.

[0016] In some embodiments, the method for manufacturing an embedded microstrip filter further comprises: forming a metal ground on a bottom surface of the substrate.

[0017] The present application also provides a power amplifier, comprising: an input matching network; a power amplifier tube; and an output matching network, wherein the output matching network comprises an embedded microstrip filter according to the embodiment of the present application.

[0018] The present application also provides an electronic device comprising a power amplifier according to the embodiment of the present application.

[0019] According to the embedded microstrip filter and the manufacturing method thereof, the power amplifier comprising the embedded microstrip filter, and the electronic device, the filter structure is embedded in the microstrip transmission line, which can reduce the occupied space, so as to realize the filtering function without occupying additional space, and will not have a great influence on the original transmission of the working frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the specific embodiments described below to explain the technical solutions of the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0021] Figure 1 This illustrates how the filter structure and output matching network in the power amplifier are connected in series.

[0022] Figure 2 This illustrates how the filter structure and output matching network in the power amplifier are connected in parallel;

[0023] Figure 3 A schematic diagram of an embedded microstrip filter according to an embodiment of this application is shown;

[0024] Figure 4 An example of an embedded microstrip filter according to an embodiment of this application is shown;

[0025] Figure 5 A cross-sectional view of an embedded microstrip filter according to an embodiment of this application is shown;

[0026] Figure 6 A schematic diagram of a power amplifier according to an embodiment of this application is shown;

[0027] Figure 7 It shows that Figure 4 The embedded microstrip filter shown is applied to Figure 6 A schematic diagram of the power amplifier shown;

[0028] Figure 8 The suppression simulation effect of the microstrip filter according to an embodiment of this application is shown;

[0029] Figure 9 The effect of an embedded microstrip filter according to an embodiment of this application on the impedance of the output matching network is illustrated.

[0030] Figure 10 A design flowchart of an embedded microstrip filter according to an embodiment of this application is shown;

[0031] Figure 11 Another example of an embedded microstrip filter according to an embodiment of this application is shown;

[0032] Figure 12 A schematic diagram is shown where the distributed element is a coil inductor;

[0033] Figure 13 A schematic diagram is shown where the distributed element is an interdigital capacitor;

[0034] Figure 14 Another design flowchart of an embedded microstrip filter according to an embodiment of this application is shown;

[0035] Figure 15 A flowchart illustrating a method for fabricating an embedded microstrip filter according to an embodiment of this application is shown; and

[0036] Figure 16 A schematic diagram of an electronic device according to embodiments of the application is shown. DETAILED DESCRIPTION

[0037] For a better understanding of the technical solutions of the present disclosure, example embodiments will be described in more detail in the following with reference to the drawings, but the example embodiments can be embodied in various forms and should not be interpreted as being limited to the embodiments set forth herein. The purpose of providing these embodiments is to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. It should be recognized that the drawings are only used to describe the embodiments of the present disclosure, and the sizes of the various elements or parts shown in the drawings are not drawn according to the actual proportions.

[0038] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to limit the claimed subject matter. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0040] It will be understood that, although the terms "first" and "second" are used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections are not limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Therefore, a first element, component, region, layer or section discussed below can be called a second element, component, region, layer or section without departing from the teachings disclosed herein. In addition, a first element, component, region, layer or section in one embodiment can be different from a first element, component, region, layer or section in another embodiment.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0042] It will be further understood that the description of features or aspects within each example embodiment should generally be considered to extend to other similar features or aspects in other example embodiments, unless the context clearly indicates otherwise. The various embodiments of the present disclosure and various features thereof can be combined with one another unless the context clearly indicates otherwise.

[0043] For power amplifier systems, the concurrent of multi-frequency signals makes the spectrum components more complex due to the nonlinearity of the power amplifier itself. In addition to the effect of harmonics, out-of-band intermodulation components are also generated, which have a great impact on the performance of the power amplifier. A microstrip-based filtering structure can be used to suppress the out-of-band intermodulation.

[0044] In the related art, the filtering structure in the power amplifier mainly has two ways of series and parallel. Figure 1 The way of series of the filtering structure and the output matching network is shown, Figure 2 The way of parallel of the filtering structure and the output matching network is shown. However, both the series and parallel schemes will occupy extra space outside the output matching network of the power amplifier, which is difficult to realize in the case of tight layout space of the circuit board.

[0045] The present application provides an embedded microstrip filter which can be used for the output matching network of the power amplifier, and can realize the filtering function without occupying extra space and without having a great impact on the original transmission frequency band. In the multi-frequency concurrent application scenario, the embedded microstrip filter provided by the present application can effectively filter out the low-frequency intermodulation signals generated due to the nonlinearity of the power amplifier between the concurrent frequency bands, and improve the linear performance and efficiency of the power amplifier.

[0046] Figure 3 A schematic diagram of the embedded microstrip filter according to an embodiment of the present application is shown.

[0047] As Figure 3 As shown, the embedded microstrip filter according to the present application includes a microstrip transmission line 101 and a filtering structure. The filtering structure is embedded in the microstrip transmission line 101. The filtering structure includes at least one column of a plurality of island-shaped metal patches 102, and a plurality of capacitive or inductive elements 103. The plurality of capacitive or inductive elements 103 connect the plurality of metal patches 102 with the microstrip transmission line 101.

[0048] According to an embodiment of the present application, the plurality of metal patches 102 are arranged in a matrix, i.e., at least one column of the plurality of metal patches 102 comprises a plurality of columns of metal patches 102, and the plurality of capacitive or inductive elements 103 connect two metal patches in two adjacent columns to each other.

[0049] Figure 4 An example of an embedded microstrip filter according to an embodiment of the present application is shown.

[0050] As shown in Figure 4 The filter structure comprises a plurality of metal patches 102 arranged in a matrix and a plurality of capacitive or inductive elements 103 arranged in a matrix, and the filter structure is embedded in the microstrip transmission line 101.

[0051] The microstrip transmission line 101 is a low-impedance microstrip transmission line. The cross-sectional width of the low-impedance microstrip transmission line is wide, and a larger rectangular gap can be etched in the microstrip transmission line 101 so as to embed the filter structure therein, and such a larger rectangular gap will not have a large impact on the transmission of the fundamental frequency band. In the process of etching the microstrip transmission line 101 to form the rectangular gap, a plurality of metal patches 102 in the form of islands can be reserved.

[0052] According to an embodiment of the present application, the capacitive or inductive elements 103 can be surface-mounted lumped elements.

[0053] Surface-mounted elements refer to electronic components suitable for assembly using the surface mount process, including surface-mounted components (SMC) and surface-mounted devices (SMD). Lumped elements refer to the fact that if the actual circuit element or component has an outer size much smaller than the wavelength of the electromagnetic wave signal passing through it, the outer size of the circuit element or component can be ignored, i.e., the effect of the element on the circuit can be ideally equivalent to a point.

[0054] According to an embodiment of the present application, for low-frequency applications, the capacitive or inductive elements 103 can take the form of lumped capacitive or inductive elements. The implementation form of the surface-mounted lumped capacitive or inductive elements can be arbitrary, including but not limited to common packaging processes such as ceramic packaging. In addition, when the capacitive or inductive elements 103 take the form of surface-mounted lumped elements, i.e., the capacitive or inductive elements 103 are surface-mounted lumped capacitors or surface-mounted lumped inductors, the capacitive or inductive elements 103 can be mounted on a circuit board (e.g., a printed circuit board (PCB)) by soldering.

[0055] The specific form of the capacitive or inductive element 103 can be determined according to the direction in which the impedance of the suppression frequency band is to be pulled, for example, a capacitive element can be used if it is desired to pull the impedance of the suppression frequency band to an open-circuit point, and an inductive element can be used if it is desired to pull the impedance of the suppression frequency band to a short-circuit point.

[0056] It should be appreciated that, although Figure 4 The filter structure is shown to include 5 rows of 3 metal patches 102 and 5 rows of 4 capacitive or inductive elements 103 in the middle, but those skilled in the art can understand that the filter structure shown in the figure is only an example, and the size, number and arrangement of the metal patches and the capacitive or inductive elements can be determined according to actual conditions.

[0057] Figure 5 A cross-sectional view of the embedded microstrip filter according to an embodiment of the present application is shown.

[0058] As Figure 5 shown, the embedded microstrip filter according to an embodiment of the present application further includes a substrate 104 and a ground metal 105. The microstrip transmission line 101 and the filter structure embedded in the microstrip transmission line 101 are disposed on the top surface of the substrate 104, and the metal ground 105 is disposed on the bottom surface of the substrate 104.

[0059] The microstrip transmission line 101 and the ground metal 105 can be formed as a metal layer, and the substrate 104 can be formed as a dielectric plate. Etching is performed on the microstrip transmission line 101 to form a rectangular gap and a plurality of metal patches embedded in the rectangular gap, and no etching operation is performed on the ground metal 105.

[0060] Figure 6 A schematic diagram of a power amplifier according to an embodiment of the present application is shown, Figure 7 A schematic diagram of a power amplifier according to an embodiment of the present application is shown, Figure 4 The embedded microstrip filter shown in Figure 6 The schematic diagram of the power amplifier shown in

[0061] As Figure 6 and Figure 7 shown, the filter structure is embedded in the microstrip structure of the output matching network of the power amplifier, so it does not increase the additional space occupation.

[0062] Figure 8 The suppression simulation effect of the microstrip filter according to an embodiment of the present application is shown, Figure 3 The suppression simulation effect of the embodiment shown in Figure 8 can be characterized by the S parameter table shown in

[0063] Referring to Figure 3The structural dimensions of the island-shaped metal patch 102 and the capacitor or inductor element 103 affect the center frequency value of the suppression band. When the capacitor or inductor element 103 is a capacitor, the larger the capacitance parameter or the larger the size of the metal patch, the lower the suppression band shifts. In addition, the number of metal patches 102 and capacitors or inductors 103 affects the relative bandwidth of the suppression band; the more there are, the wider the relative bandwidth. For out-of-band frequencies without suppression, the characteristic impedance of the parallel transmission line composed of multiple parallel branches formed by the metal patch 102 and capacitors or inductors 103, and the narrow microstrip lines on both sides of the filter structure, is basically consistent with the characteristic impedance of low-impedance microstrip transmission lines in related technologies. Therefore, it can exhibit characteristics of basically unchanged input impedance or basically no additional insertion loss out of the band.

[0064] like Figure 8 As shown, after loading, a significant suppression effect is produced in the 800MHz intermodulation band, with an in-band suppression of over 10dB in the 0.767-0.865GHz range. In the 1.8-2.7GHz signal transmission band (i.e., within the range of m3 to m2), the impact on impedance is minimal. The port is an 18-ohm lumped port with an insertion loss of approximately 0.04-0.08dB, close to the 0.05-0.08dB performance of the original length microstrip.

[0065] Figure 9 The effect of an embedded microstrip filter according to an embodiment of this application on the impedance of an output matching network (OMN) is illustrated.

[0066] like Figure 9 As shown, line segments m1 to m2 represent the fundamental impedance before the embedded microstrip filter according to an embodiment of this application, within the 1.8-2.7 GHz fundamental frequency band; line segments m3 to m4 represent the fundamental impedance after the embedded microstrip filter according to an embodiment of this application, within the 1.8-2.7 GHz fundamental frequency band; line segments m5 to m6 represent the intermodulation impedance before the embedded microstrip filter according to an embodiment of this application, within the 740-885 MHz low-frequency intermodulation band; and line segments m7 to m8 represent the intermodulation impedance after the embedded microstrip filter according to an embodiment of this application, within the 740-885 MHz low-frequency intermodulation band. It can be seen that within the 1.8-2.7 GHz fundamental frequency band, the variation in fundamental impedance is relatively small, and the target impedance position can be restored through appropriate optimization. However, in the 740-885 MHz low-frequency intermodulation band, the impedance is significant, and the Smith chart pulls outwards.

[0067] According to the embedded microstrip filter of this application, the filtering structure is embedded within the microstrip transmission line, which reduces the space occupied and enables filtering without occupying additional space, without significantly affecting the transmission of the original operating frequency band. In multi-frequency concurrent application scenarios, the embedded microstrip filter provided by this application can effectively filter out low-frequency intermodulation signals generated between concurrent frequency bands due to the nonlinearity of the power amplifier, thereby improving the linear performance and efficiency of the power amplifier.

[0068] Figure 10 A design flowchart of an embedded microstrip filter according to an embodiment of this application is shown.

[0069] like Figure 10 The diagram illustrates the design flow when the capacitors or inductors are surface-mount lumped elements. The design flow for an embedded microstrip filter according to an embodiment of this application includes steps S110 to S130.

[0070] In step S110, the output matching network of the power amplifier is shaped.

[0071] Based on actual needs, complete the design of the shape and size of the output matching network for the power amplifier. For example, complete the design. Figure 4 The microstrip transmission line shown.

[0072] In step S120, simulation is performed based on the suppression band bandwidth and center frequency to determine the number and size of the metal patches, as well as the type and parameters of the surface-mount lumped elements.

[0073] Simulations can determine the number and size of metal patches, as well as the type and parameters of surface-mount lumped elements (i.e., capacitors or inductors). The structural dimensions of the metal patches and capacitors or inductors affect the center frequency of the suppression band. For example, larger capacitor parameters or larger metal patch sizes shift the suppression band further down the frequency spectrum. The number of metal patches and capacitors or inductors affects the relative bandwidth of the suppression band; more patches result in a wider relative bandwidth. Furthermore, the type of capacitor or inductor can be determined based on the direction of impedance pull in the suppression band. For example, capacitors can be used to pull the suppression band impedance towards the open circuit point, while inductors can be used to pull it towards the short circuit point.

[0074] In step S130, the package size and model of the patch lumped element are determined based on the spacing between the metal patches.

[0075] In this embodiment, the capacitor or inductor is a surface-mount lumped element. The spacing between the metal patches can be obtained based on the number and size of the metal patches in the design, and the package size and model of the lumped element can be determined based on the spacing between the metal patches to complete the design.

[0076] Figure 11 Another example of an embedded microstrip filter according to an embodiment of this application is shown.

[0077] According to embodiments of this application, the capacitor or inductor element 103 may be a distributed element 107.

[0078] It should be recognized that the size of the distributed element 107 is generally large. Therefore, the number of metal patches 102 and distributed elements 107 in this embodiment will be less than the number of metal patches 102 and surface-mount lumped elements in the embodiment where the capacitor or inductor element 103 is implemented by surface-mount lumped elements.

[0079] According to embodiments of this application, for high-frequency applications, the capacitor or inductor element 103 can be in the form of a distributed capacitor or inductor element. Furthermore, when the capacitor or inductor element 103 is in the form of a distributed element, that is, when the capacitor or inductor element 103 is a distributed capacitor or a distributed inductor, a pattern of the distributed capacitor or distributed inductor element can be formed on a metal layer by etching the microstrip transmission line 101 to form the capacitor or inductor element 103.

[0080] According to embodiments of this application, the distributed element 107 includes a coil inductor, such as... Figure 12 As shown.

[0081] According to embodiments of this application, the distributed element 107 includes interdigital capacitors, such as... Figure 13 As shown.

[0082] Figure 14 Another design flowchart of an embedded microstrip filter according to an embodiment of this application is shown.

[0083] like Figure 14 The diagram illustrates a design flow where the capacitors or inductors are distributed components. The design flow for an embedded microstrip filter according to an embodiment of this application includes steps S110 and S140 to S150.

[0084] In step S110, the output matching network of the power amplifier is shaped.

[0085] Based on actual needs, complete the design of the shape and size of the output matching network for the power amplifier. For example, complete the design. Figure 11 The microstrip transmission line shown.

[0086] In step S140, simulation is performed based on the suppression band bandwidth and center frequency to determine the number and size of the metal patches, as well as the type of distributed components and the parameters of their equivalent components.

[0087] Simulation can determine the number and size of metal patches, as well as the type of distributed components (i.e., capacitors or inductors) and the parameters of their equivalent components. The type of capacitor or inductor can be determined based on the direction of impedance pull in the suppression band. For example, if it is desired to pull the suppression band impedance towards the open circuit point, a capacitor can be used; if it is desired to pull the suppression band impedance towards the short circuit point, an inductor can be used.

[0088] In step S150, the size and shape of the distributed element are determined based on the parameters of the equivalent element of the distributed element.

[0089] Based on the actual situation and the parameters of the equivalent element of the distributed element, determine the specific shape and size of the distributed element in order to complete the design.

[0090] Figure 15 A flowchart illustrating a method for fabricating an embedded microstrip filter according to an embodiment of this application is shown.

[0091] like Figure 15 As shown, the method for fabricating an embedded microstrip filter according to an embodiment of this application includes steps S210 to S230.

[0092] In step S210, a microstrip transmission line is formed on the top surface of the substrate.

[0093] In step S220, the microstrip transmission line is etched to form a rectangular gap, wherein at least one column of multiple island-shaped metal patches is retained in the rectangular gap.

[0094] In step S230, a plurality of capacitors or inductors are formed on the substrate, wherein the plurality of capacitors or inductors connect a plurality of metal patches to microstrip transmission lines.

[0095] It should be understood that although the steps of forming the microstrip transmission line and forming the metal patch are described as two steps in this embodiment, those skilled in the art will understand that they can be achieved in a single etching process on the substrate (see [link]). Figure 5 Microstrip transmission lines and multiple metal patches embedded in the microstrip transmission lines are formed in the metal layer on the top surface of the microstrip transmission line.

[0096] According to an embodiment of this application, multiple metal patches are arranged in a matrix, and multiple capacitors or inductors connect two metal patches in adjacent columns to each other.

[0097] According to an embodiment of this application, the plurality of capacitors or inductors are surface-mount lumped elements, and forming the plurality of capacitors or inductors on the substrate (i.e., step S230) includes: soldering the surface-mount lumped elements onto the substrate, such that the plurality of capacitors or inductors connect the plurality of metal patches to the microstrip transmission line.

[0098] According to an embodiment of this application, the plurality of capacitors or inductors are distributed elements, and forming the plurality of capacitors or inductors on the substrate (i.e., step S230) includes: forming the plurality of capacitors or inductors on the substrate by etching the microstrip transmission line.

[0099] It should be understood that although the steps of forming the microstrip transmission line, forming the metal patch, and forming the capacitor or inductor element are described as three steps in this embodiment, those skilled in the art will understand that when multiple capacitors or inductors are distributed elements, they can be formed on the substrate (see [reference]) in a single etching process. Figure 5 Microstrip transmission lines are formed in the metal layer on the top surface of the microstrip transmission lines, as well as multiple metal patches embedded in the microstrip transmission lines and multiple capacitors or inductors connecting the multiple metal patches.

[0100] According to embodiments of this application, the distributed element includes a coil inductor or an interdigital capacitor.

[0101] According to embodiments of this application, a method for fabricating an embedded microstrip filter further includes forming a metal ground on the bottom surface of a substrate.

[0102] This application also provides a power amplifier, see [link to relevant documentation]. Figure 6 The power amplifier according to embodiments of this application includes: an input matching network; a power amplifier tube; and an output matching network, wherein the output matching network includes an embedded microstrip filter according to various embodiments of this application.

[0103] According to the power amplifier of this application, the filter structure is embedded within the microstrip transmission line, which reduces the space occupied and enables filtering without occupying additional space, without significantly affecting the transmission of the original operating frequency band. In multi-frequency concurrent application scenarios, the filter structure in the power amplifier provided by this application can effectively filter out low-frequency intermodulation signals generated between concurrent frequency bands due to the nonlinearity of the power amplifier, thereby improving the linear performance and efficiency of the power amplifier.

[0104] This application also provides an electronic device, see [link to relevant documentation] Figure 16 An electronic device according to an embodiment of this application includes a power amplifier according to various embodiments of this application.

[0105] It should be recognized that the electronic device according to the embodiments of this application can be implemented as a variety of different types of electronic devices, including (but not limited to) wireless base station devices. For example, the electronic device according to the embodiments of this application can be applied to active antenna unit (AAU) base station systems with large antenna apertures in the microwave or millimeter wave bands.

[0106] When a wireless base station device includes a power amplifier according to an embodiment of this application, the filtering structure is embedded within the microstrip transmission line, which reduces the space occupied. This allows filtering to be achieved without consuming additional space and without significantly impacting the transmission of the original operating frequency band. In multi-frequency concurrent application scenarios, the wireless base station device can effectively filter out low-frequency intermodulation signals generated between concurrent frequency bands due to the nonlinearity of the power amplifier, improving the linear performance and efficiency of the power amplifier.

[0107] This application has disclosed exemplary embodiments, and although specific terminology has been used, it is used and should be interpreted only in a general illustrative sense and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. An embedded microstrip filter, comprising: Microstrip transmission line; as well as A filtering structure is embedded within the microstrip transmission line. The filter structure includes at least one column of multiple island-shaped metal patches, and multiple capacitors or inductors. The plurality of capacitors or inductors connect the plurality of metal patches to the microstrip transmission line.

2. The embedded microstrip filter according to claim 1, wherein, The plurality of metal patches are arranged in a matrix, and the plurality of capacitors or inductors connect two metal patches in adjacent columns to each other.

3. The embedded microstrip filter according to claim 1, wherein, The plurality of capacitors or inductors are surface-mount lumped elements.

4. The embedded microstrip filter according to claim 1, wherein, The plurality of capacitors or inductors are distributed components.

5. The embedded microstrip filter according to claim 4, wherein, The distributed components include coil inductors or interdigital capacitors.

6. The embedded microstrip filter according to claim 1, further comprising: Substrate and metal ground, The microstrip transmission line and the filter structure are disposed on the top surface of the substrate, and The metal ground is disposed on the bottom surface of the substrate.

7. A method for fabricating an embedded microstrip filter, comprising: Microstrip transmission lines are formed on the top surface of the substrate; The microstrip transmission line is etched to form a rectangular gap, wherein at least one column of multiple island-shaped metal patches is retained within the rectangular gap; and Multiple capacitors or inductors are formed on the substrate, wherein the multiple capacitors or inductors connect the multiple metal patches to the microstrip transmission line.

8. The method for fabricating an embedded microstrip filter according to claim 7, wherein, The plurality of metal patches are arranged in a matrix, and the plurality of capacitors or inductors connect two metal patches in adjacent columns to each other.

9. The method for fabricating an embedded microstrip filter according to claim 7, wherein, The plurality of capacitors or inductors are surface-mount lumped elements, and the formation of the plurality of capacitors or inductors on the substrate includes: Surface-mount lumped elements are soldered onto the substrate, such that the plurality of capacitors or inductors connect the plurality of metal patches to the microstrip transmission line.

10. The method for fabricating an embedded microstrip filter according to claim 7, wherein, The plurality of capacitors or inductors are distributed elements, and the formation of the plurality of capacitors or inductors on the substrate includes: The plurality of capacitors or inductors are formed on the substrate by etching the microstrip transmission lines.

11. The method for fabricating an embedded microstrip filter according to claim 10, wherein, The distributed components include coil inductors or interdigital capacitors.

12. The method for fabricating an embedded microstrip filter according to claim 7, further comprising: A metallic ground is formed on the bottom surface of the substrate.

13. A power amplifier, comprising: Input matching network; Power amplifier tube; as well as Output matching network, The output matching network includes an embedded microstrip filter according to any one of claims 1 to 6.

14. An electronic device comprising the power amplifier according to claim 13.

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