Microstrip antenna

Abstract

This invention discloses a microstrip antenna comprising an insulating carrier, an antenna, a grounding element, and a power divider. The antenna is mounted on the insulating carrier and includes a circular body and two circular feed points. The circular body has a first center and a radius. The two circular feed points are surrounded by the circular body. The two circular feed points do not contact the circular body but can generate a capacitive effect with it. Each circular feed point has a second center. Each second center has a shortest distance from the first center. The shortest distance is less than half the radius. The grounding element is disposed on the insulating carrier. The power divider is electrically coupled to the two circular feed points, and the power divider enables a 90-degree phase difference between the circular feed points. Accordingly, the microstrip antenna can improve isolation and reduce axial ratio.

Description

Technical Field

[0001] This invention relates to an antenna, and more particularly to a microstrip antenna. Background Technology

[0002] Existing microstrip antennas are widely used in electronic products (e.g., mobile phones) because they can be directly printed on circuit boards and are inexpensive. To ensure optimal operation (e.g., preventing interference from components within the electronic product), factors such as isolation and axial ratio are considered during the design phase. However, as the development of existing microstrip antennas has matured, they can no longer provide better isolation or lower axial ratios.

[0003] Therefore, the inventor believed that the above-mentioned defects could be improved, and thus devoted himself to research and applied scientific principles, and finally proposed an invention that is reasonably designed and effectively improves the above-mentioned defects. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a microstrip antenna that addresses the shortcomings of the prior art.

[0005] This invention discloses a microstrip antenna, comprising: an insulating carrier; an antenna disposed on the insulating carrier, the antenna comprising: a circular body having a first center and a radius; and two circular feed points surrounded by the circular body, the two circular feed points not contacting the circular body but generating a capacitive effect with the circular body, each circular feed point having a second center, each second center having a shortest distance from the first center, the shortest distance being less than 1 / 2 of the radius; a grounding element disposed on the insulating carrier; and a power divider electrically coupled to the two circular feed points, the power divider enabling a 90-degree phase difference between the two circular feed points.

[0006] Preferably, the insulating carrier includes a first layer, a second layer, and at least one interlayer located between the first layer and the second layer, the circular body is disposed on the antenna disposed on the first layer, the power divider is disposed on the second layer, and the grounding element is disposed on the second layer or the at least one interlayer.

[0007] Preferably, the first and second layers are further defined as a circuit board, and the interlayer is further defined as an air medium.

[0008] Preferably, the first layer, the second layer and the interlayer are further defined as a circuit board.

[0009] Preferably, the at least one interlayer has two perforations, and the antenna further includes two conductive posts passing through the two perforations, such that the two ends of each conductive post are electrically coupled to the power divider and the circular feed point.

[0010] In summary, the microstrip antenna disclosed in the embodiments of the present invention can effectively improve isolation and reduce axial ratio by designing that "the two circular feed points do not contact the circular body and can generate a capacitance effect with the circular body" and "the second center of each of the two circular feed points has a shortest distance between it and the first center of the circular body, and the shortest distance is less than 1 / 2 of the radius".

[0011] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0012] Figure 1 This is a three-dimensional schematic diagram of a microstrip antenna according to the first embodiment of the present invention.

[0013] Figure 2 This is another three-dimensional schematic diagram of the microstrip antenna according to the first embodiment of the present invention.

[0014] Figure 3 This is a top view schematic diagram of the microstrip antenna according to the first embodiment of the present invention.

[0015] Figure 4 This is a bottom view of the microstrip antenna according to the first embodiment of the present invention.

[0016] Figure 5 for Figure 3 A cross-sectional view along the VV section line.

[0017] Figure 6 This is a schematic diagram of the axial ratio data of the microstrip antenna according to the first embodiment of the present invention.

[0018] Figure 7 This is a schematic diagram of the measured peak gain data of the microstrip antenna according to the first embodiment of the present invention.

[0019] Figure 8 This is a cross-sectional schematic diagram of a microstrip antenna according to a second embodiment of the present invention.

[0020] Figure 9 This is a planar schematic diagram of the antenna array according to the third embodiment of the present invention.

[0021] Figure 10 This is another planar schematic diagram of the antenna array according to the third embodiment of the present invention.

[0022] Figure 11 This is a plan view of the antenna array connection lines according to the third embodiment of the present invention. Reference numerals in the above figures:

[0023] 1000: Antenna array

[0024] 100, 100', 100”: Microstrip antenna

[0025] 1: Insulating carrier

[0026] 11: First floor

[0027] 12: Second layer

[0028] 13: Mezzanine

[0029] H13: Perforation

[0030] 2: Circular main body

[0031] H21: Circular through hole

[0032] 3: Circular feed point

[0033] 4: Grounding component

[0034] H4: Clearance Hole

[0035] 5: Conductive pillar

[0036] 6: Power divider

[0037] C1: First center

[0038] C2: Second center

[0039] R: radius

[0040] D1: Shortest distance

[0041] L1: First extension line

[0042] L2: Second extension line

[0043] SC: Shared Carrier

[0044] AS: Antenna Structure

[0045] S1: First panel

[0046] S2: Second panel

[0047] D1: First Direction

[0048] D2: Second Direction

[0049] RO1: First row

[0050] RO2: Second row

[0051] CO1: First column

[0052] CO2: Second column

[0053] CP1: First Rotation Point

[0054] CP2: Second Rotation Point

[0055] CL1: First Centerline

[0056] CL2: Second centerline

[0057] 200: Line Detailed Implementation

[0058] The following specific embodiments illustrate the implementation of the "microstrip antenna" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated beforehand. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention.

[0059] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used in this document should, as appropriate, include any combination of one or more of the related listed items.

[0060] Additionally, in the following description, if it is indicated that a specific diagram is referred to or as shown in a specific diagram, it is only to emphasize that most of the relevant content in the following description appears in that specific diagram, but does not limit the following description to refer only to that specific diagram.

[0061] [First Embodiment]

[0062] See Figures 1 to 7 As shown, this embodiment provides a microstrip antenna 100, which is suitable for broadband applications. Figure 1 and Figure 2As shown, the microstrip antenna 100 includes an insulating carrier 1, a circular body 2 disposed on the insulating carrier 1, two circular feed points 3, a grounding element 4 and two conductive posts 5, and a power divider 6 electrically coupled to the two circular feed points 3. Next, the components of the microstrip antenna 100 and their connections will be described.

[0063] Cooperate Figure 1 , Figure 2 and Figure 5 As shown, the insulating carrier 1 in this embodiment is a multilayer printed circuit board, and the insulating carrier 1 includes a first layer 11, a second layer 12, and an interlayer 13 located between the first layer 11 and the second layer 12.

[0064] In a practical application, the first layer 11 and the second layer 12 may be solid components (i.e., circuit boards), and the first layer 11 and the second layer 12 may be supported by an insulating support (not shown) such that the first layer 11 and the second layer 12 are spaced apart from each other to have the interlayer 13 as an air medium.

[0065] Re-reference Figure 1 , Figure 3 and Figure 5 As shown, the circular body 2 in this embodiment is a sheet-like conductive material (e.g., copper foil). The circular body 2 is disposed on the side of the first layer 11 away from the second layer 12, and the circular body 2 has a first center C1 and a radius R.

[0066] Furthermore, the circular body 2 also has two circular through holes H21, and a portion of the first layer 11 can be exposed through the two circular through holes H21. The areas of the two circular through holes H21 must be larger than the areas of the two circular feed points 3, so that the two circular through holes H21 can respectively accommodate the two circular feed points 3. The two circular feed points 3 are respectively located at the center of the two circular through holes H21, so that the two circular feed points 3 are surrounded by the circular body 2 without contacting each other, and the two circular feed points 3 can generate a capacitive effect with the circular body 2.

[0067] It is worth noting that the two circular feed points 3 in this embodiment are also sheet-like conductive materials (e.g., copper foil), and the positional relationship between the two circular feed points 3 and the circular body 2 is particularly important to ensure that the capacitance effect can improve the isolation and reduce the axial ratio. Specifically, each circular feed point 3 has a second center C2, and the second center C2 of each of the two circular feed points 3 must have a shortest distance D1 with the first center C1 of the circular body 2, and the shortest distance D1 is preferably less than 1 / 2 of the radius R. In other words, the positions of the two circular feed points 3 are adjacent to the center of the circular body 2.

[0068] In a preferred application, the area of ​​each circular feed point 3 is preferably no greater than 1 / 4 of the area of ​​the circular body 2, to ensure that the two circular feed points 3 have a reasonable and appropriate capacitance effect with the circular body 2. Furthermore, a first extension line L1 can pass between the second center C2 of one of the circular feed points 3 and the first center C1 of the circular body 2, and a second extension line L2 can pass between the second center C2 of the other circular feed point 3 and the first center C1 of the circular body 2, and the first extension line L1 and the second extension line L2 can have an included angle of 90 degrees.

[0069] Re-reference Figure 1 and Figure 5 As shown, the two conductive posts 5 in this embodiment are columnar structures, and the two conductive posts 5 are respectively installed between the first layer 11 and the second layer 12. The positions of the two conductive posts 5 correspond to the two circular feed points 3, and one end of each of the two conductive posts 5 can pass through the first layer 11 to electrically couple to the two circular feed points 3, and the other end of each of the two conductive posts 5 can pass through the second layer 12 to connect to the power divider 6.

[0070] In this embodiment, the grounding element 4 is a sheet-like conductive material (e.g., copper foil), and it is disposed on the side of the second layer 12 facing the first layer 11. The grounding element 4 has two clearance holes H4, and the positions of the two clearance holes H4 correspond to the two conductive posts 5, ensuring that the grounding element 4 does not contact the two conductive posts 5. Furthermore, the grounding element 4 can preferably completely cover the side of the second layer 12 facing the first layer 11, but this is not a limitation of the invention.

[0071] Cooperate Figure 2 , Figure 4 and Figure 5As shown, the power divider 6 in this embodiment can be a Wilkinson power divider and can be used to receive signals from a beamforming chip (BFIC). The power divider 6 is disposed on the side of the second layer 12 away from the first layer 11, and the power divider 6 can be electrically coupled to the two circular feed points 3 through the other ends of the two conductive posts 5, thereby feeding the two circular feed points 3 to generate a phase difference of 90 degrees. Accordingly, the microstrip antenna 100 can generate a circularly polarized field pattern and can also cooperate with the beamforming chip to achieve beam control.

[0072] It should be noted that, Figure 6 The chart shown presents the axial ratio data of the microstrip antenna 100 obtained experimentally. Figure 7 The chart shown represents the peak gain data of the microstrip antenna 100 obtained experimentally. The axial ratio data shows that when the microstrip antenna 100 operates between 10.6 MHz and 14 MHz, its axial ratio is less than 3 dB. Furthermore, when the microstrip antenna 100 operates between 11.6 MHz and 13.6 MHz, its axial ratio is less than 1.2 dB. Moreover, the peak gain data shows that when the microstrip antenna operates between 10.9 MHz and 13 MHz, its peak gain is greater than 2 dB. In other words, the microstrip antenna 100 of the present invention not only possesses the advantage of a low axial ratio but also has the effect of improving gain.

[0073] [Second Embodiment]

[0074] like Figure 8 As shown, this is the second embodiment of the present invention. The microstrip antenna 100' in this embodiment is similar to the microstrip antenna 100 in the first embodiment described above. The similarities between the two embodiments will not be repeated. The main difference between the microstrip antenna 100' in this embodiment and the first embodiment is that:

[0075] Cooperate Figure 8 As shown, the first layer 11, the second layer 12, and the interlayer 13 in this embodiment are all circuit boards, and the grounding member 4 is disposed on a surface of the interlayer 13 facing the first layer 11. Furthermore, the interlayer 13 also has two through holes H13, and the positions of the two through holes H13 correspond to the two conductive posts 5, allowing the two conductive posts 5 to penetrate the interlayer 13. In this embodiment, each conductive post 5 can also be a via hole, but this is not a limitation of the invention.

[0076] Accordingly, when the mezzanine 13 is a (high-frequency) circuit board, the mezzanine 13 can be used as a power supply and control circuit. Furthermore, in the manufacturing process of the microstrip antenna 100' of this embodiment, the microstrip antenna 100' is also easier to manufacture than the microstrip antenna 100 of the first embodiment (especially, array antennas).

[0077] Additionally, it should be noted that in other embodiments of the present invention not shown, the insulating carrier 1 may also include a plurality of the interlayers 13 and a plurality of the grounding elements 4, wherein a portion of the plurality of interlayers 13 may be a circuit board, and another portion of the plurality of interlayers 13 may be an air medium. The plurality of grounding elements 4 are disposed on the plurality of interlayers 13 that are circuit boards.

[0078] Of course, all of the aforementioned interlayers 13 can be circuit boards, and the present invention is not particularly limited thereto. In other words, the number of the interlayers 13 of the insulating carrier 1 and the grounding member 4 can be at least one.

[0079] [Third Embodiment]

[0080] like Figures 9 to 11 As shown, this is the third embodiment of the present invention. The antenna array 1000 in this embodiment includes a shared carrier SC and four microstrip antennas 100 disposed on the shared carrier SC. Next, the components of the antenna array 1000 and their connection relationships are described.

[0081] Cooperate Figure 9 and Figure 10 As shown, the shared carrier SC has a first plate surface S1 and a second plate surface S2 that are opposite to each other, and the shared carrier has a first direction D1 and a second direction D2 perpendicular to the first direction D1. In this embodiment, the shared carrier SC can be, for example, a plurality of the insulating carriers 1 of the first embodiment or the second embodiment. That is, the structure of the shared carrier SC in this embodiment is similar to the insulating carrier 1 of the first embodiment or the second embodiment described above. Therefore, the similarities between the two embodiments will not be repeated.

[0082] In other words, the shared carrier SC also includes the first layer 11, the second layer 12, and the interlayer 13 located between the first layer 11 and the second layer 12 (e.g., Figure 5 or Figure 8 (As shown). The surface of the first layer 11 that is away from the second layer 12 is defined as the first plate surface S1, and the surface of the second layer 12 that is away from the first layer 11 is defined as the second plate surface S2.

[0083] Re-reference Figure 9 and Figure 10As shown, each of the microstrip antennas 100” in this embodiment can be, for example, the microstrip antennas 100 and 100' of the first or second embodiment. That is, the structure of each of the microstrip antennas 100” in this embodiment is similar to that of the microstrip antennas 100 and 100' of the first or second embodiment and has the circular body 2, two circular feed points 3, the grounding element 4, two conductive posts 5, and the power divider 6 (e.g., Figure 1 As shown in the figure, the similarities between the two embodiments will not be repeated. For ease of explanation, the circular body 2 and the two circular feed points 3 of each microstrip antenna 100” can be further defined as an antenna structure AS.

[0084] It should be noted that, in order to reduce the number of lines 200 on the shared carrier SC (e.g., Figure 11 The area of ​​the four microstrip antennas 100” (as shown) is connected to the area of ​​the four microstrip antennas 100”, which can be configured as follows.

[0085] Specifically, four microstrip antennas 100” are spaced apart from each other on the shared carrier SC, and the four microstrip antennas 100” are arranged in a matrix along the first direction D1 and the second direction D2. Furthermore, viewed from the first plate surface S1, two adjacent antenna structures AS along the second direction D2 have a 180-degree rotational symmetry relationship. Viewed from the second plate surface S2, two adjacent power dividers 6 along the first direction D1 and the second direction D2 have a mirror symmetry relationship.

[0086] For example, such as Figure 9 As shown, taking the first plate surface S1 as an example, the first plate surface S1 has a first center line CL1 parallel to the second direction D2. The first plate surface S1 has a first rotation point CP1 between the two microstrip antennas 100” in the first column CO1, passing through the first center line CL1 (the line connecting the centers of the two circular bodies 2), and the first plate surface S1 has a second rotation point CP2 between the two microstrip antennas 100” in the second column CO2, passing through the first center line CL1 (the line connecting the centers of the two circular bodies 2). When the two circular feed points 3 of the two microstrip antennas 100” in the first row RO1 rotate 180 degrees with respect to the first rotation point CP1 and the second rotation point CP2 respectively, the two circular feed points 3 of the two microstrip antennas 100” in the first row RO1 can overlap with the two circular feed points 3 of the two microstrip antennas 100” in the second row RO2.

[0087] Furthermore, such as Figure 10As shown, taking the second plate S2 as an example, the second plate S2 has two second center lines CL2 parallel to the first direction D1 and the second direction D2. The two power dividers 6 of the first row RO1 and the second row RO2 are symmetrically arranged with the second center line CL2 parallel to the second direction D2 as the axis of symmetry, and the two power dividers 6 of the first column CO1 and the second column CO2 are symmetrically arranged with the second center line CL2 parallel to the first direction D1 as the axis of symmetry.

[0088] Of course, in other embodiments of the present invention not shown, the antenna array 1000 may contain 4M microstrip antennas 100", where M is a positive integer.

[0089] [Technical Effects of the Embodiments of the Invention]

[0090] In summary, the microstrip antenna disclosed in the embodiments of the present invention can effectively improve isolation and reduce axial ratio by designing that "the two circular feed points do not contact the circular body and can generate a capacitance effect with the circular body" and "the second center of each of the two circular feed points has a shortest distance between it and the first center of the circular body, and the shortest distance is less than 1 / 2 of the radius".

[0091] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification and drawings are included in the scope of the patent application of the present invention.

Claims

1. A microstrip antenna, characterized by, include: An insulating carrier; A circular main body is disposed on the insulating carrier, the circular main body having a first center and a radius; and Two circular feed points are surrounded by the circular body. The two circular feed points do not contact the circular body but can generate a capacitance effect with the circular body. Each circular feed point has a second center. Each second center has a shortest distance from the first center. The shortest distance is less than 1 / 2 of the radius. The area of ​​each circular feed point is not greater than 1 / 4 of the area of ​​the circular body. A grounding element is disposed on the insulating carrier; and A power divider electrically coupled to two of the circular feed points, the power divider enabling a 90-degree phase difference between the two circular feed points; The insulating carrier includes a first layer, a second layer, and at least one interlayer located between the first layer and the second layer. The circular body is disposed on the first layer, the power divider is disposed on the second layer, and the grounding element is disposed on the second layer or the at least one interlayer. The first layer and the second layer are further defined as a circuit board, and the interlayer is further defined as an air medium.

2. The microstrip antenna according to claim 1, characterized in that The first layer, the second layer, and the interlayer are further defined as a circuit board.

3. The microstrip antenna according to claim 2, characterized in that The at least one interlayer has two perforations, and the antenna further includes two conductive posts that pass through the two perforations, such that the two ends of each conductive post are electrically coupled to the power divider and the circular feed point.

4. The microstrip antenna according to claim 1, wherein A first extension line can pass between the second center of one of the circular feed points and the first center of the circular body, and a second extension line can pass between the second center of the other circular feed point and the first center of the circular body, and the first extension line and the second extension line can have an angle of 90 degrees.

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