JP7657852B2 - Antenna Array - Google Patents

Description

The present invention relates to antennas, and in particular to microstrip antennas.

Microstrip antennas are widely used in electronic products (e.g., mobile phones) because they can be printed directly on circuit boards and are inexpensive. Traditional dual-feed microstrip antennas are designed with factors such as isolation and axial ratio in mind to ensure ideal operation (e.g., avoiding interference from components inside electronic products). However, the development of traditional dual-feed microstrip antennas has matured, and traditional dual-feed microstrip antennas are no longer able to improve isolation or reduce axial ratio.

The inventor therefore believed that the above shortcomings could be remedied, and so he conducted deliberate research, applied scientific principles, and ultimately completed an invention that is rationally designed and effective in remedying the above shortcomings.

To address the above technical deficiencies, the present invention provides a microstrip antenna.

In order to solve the above-mentioned problems, one of the technical aspects adopted by the present invention is to provide a microstrip antenna. The microstrip antenna includes an insulating carrier, a circular body, two circular feed points, a ground element, and a power divider. The circular body is disposed on the insulating carrier. The circular body has a first circular center and a radius. The two circular feed points are surrounded by the circular body and are not connected to the circular body, and the two circular feed points are configured to generate a capacitive effect with the circular body. Each of the two circular feed points has a second circular center, and the shortest distance between the second circular center and the first circular center is less than 1/2 of the radius. The ground element is disposed on the insulating carrier. The power divider is electrically coupled to the two circular feed points. The power divider is configured to generate a phase difference of 90 degrees between the two circular feed points.

In one possible or preferred embodiment, the insulating carrier includes a first layer, a second layer, and at least one intermediate layer between the first layer and the second layer. The circular body portion is disposed on the first layer, the power divider is disposed on the second layer, and the ground element is disposed on the second layer or on the at least one intermediate layer.

In one preferred embodiment, each of the first and second layers is a circuit board, and at least one intermediate layer is an air medium.

In one preferred embodiment, each of the first layer, the second layer, and the at least one intermediate layer is a circuit board.

In one preferred embodiment, at least one intermediate layer has two through holes, and each of the four microstrip antennas includes two conductive pillars. The two conductive pillars pass through the two through holes such that the two ends of each of the two conductive pillars are electrically coupled to the power divider and the circular feed point.

As described above, in the microstrip antenna provided by the present invention, "the two circular feed points are configured to generate a capacitive effect with the circular body," and "each of the two circular feed points has a second center, and the shortest distance between the second center and the first center is less than 1/2 of the radius." This allows the microstrip antenna to effectively improve isolation while simultaneously reducing the axial ratio.

In order to better understand the features and technical contents of the invention, please refer to the following detailed description of the invention and the accompanying drawings. However, the accompanying drawings are provided for reference and explanation only, and are not intended to limit the scope of the claims of the invention.

1 is a schematic three-dimensional diagram of an antenna array according to a first embodiment of the present invention; FIG. 2 is another schematic three-dimensional view of the antenna array according to the first embodiment of the present invention. FIG. 2 is a schematic top view of the antenna array according to the first embodiment of the present invention. FIG. 2 is a schematic bottom view of the antenna array according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view taken along line VV in FIG. FIG. 4 is a diagram showing axial ratio data of the antenna array according to the first embodiment of the present invention. FIG. 4 is a diagram showing peak gain data of the antenna array according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of an antenna array according to a second embodiment of the present invention. FIG. 11 is a schematic top view of an antenna array according to a third embodiment of the present invention. FIG. 10 is a schematic bottom view of an antenna array according to a third embodiment of the present invention. FIG. 10 is a schematic diagram showing how circuitry is connected to an antenna array according to a third embodiment of the present invention.

The following describes the embodiments disclosed by the present invention with specific examples of the "microstrip antenna" according to the present application. Those skilled in the art can understand the advantages and effects of the present invention from the disclosure of this specification. The present invention can be implemented or applied in other different embodiments. Each subsection in this specification can be modified and changed in various aspects or applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are for simple and schematic illustration only and do not show actual dimensions. The following embodiments will further explain the technical matters related to the present invention, but the disclosed contents do not limit the present invention. In addition, the term "or" used in this specification may include any one or more combinations of related items according to the actual situation.

Throughout this specification, terms such as "first," "second," and "third" may be used to describe various components or signals, but it should be understood that these components and signals should not be limited by these terms. These terms are used primarily to distinguish one component from another or one signal from another. Additionally, as used herein, the term "or" can include any one or combination of the associated listed items, as appropriate.

Furthermore, when reference is made in the following description to a particular drawing or as shown in a particular drawing, this is intended only to emphasize that in the following description, most of the relevant content described appears in that particular drawing, and is not intended to limit the following description to references only to that particular drawing.

[First embodiment]
1 to 7, the first embodiment of the present invention provides a microstrip antenna 100 suitable for a wide band. As shown in Fig. 1 and Fig. 2, the microstrip antenna 100 includes an insulating carrier 1, a circular body 2, two circular feeding points 3, a ground element 4, and two conductive pillars 5 arranged on the insulating carrier 1, and a power divider electrically coupled to the two circular feeding points 3. In the following description, the structure and connection relationship of each component of the microstrip antenna 100 will be described.

Referring to Figures 1, 2 and 5, the insulating carrier 1 according to this embodiment is a printed wiring board having a multi-layer structure, and the insulating carrier 1 includes a first layer 11, a second layer 12, and an intermediate layer 13 located between the first layer 11 and the second layer 12.

In practical applications, the first layer 11 and the second layer 12 may be physical components (i.e., circuit boards), and the first layer 11 and the second layer 12 may be spaced apart from each other and supported by insulating supports (not shown) such that the first layer 11 and the second layer 12 have an intermediate layer 13 as an air medium.

Referring to Figures 1, 3, and 5, the circular body 2 in this embodiment is a conductive material in a sheet form (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.

Furthermore, the circular body 2 also has two circular through holes H21, and a part of the first layer 11 can be exposed by forming the two circular through holes H21. The area of the two circular through holes H21 must be larger than the area of the two circular feed points 3, so that the two circular through holes H21 can be used to accommodate the two circular feed points 3, respectively. Furthermore, since the two circular feed points 3 are respectively arranged in the central regions of the two circular through holes H21, the two circular feed points 3 are surrounded by the circular body 2 and are not connected to the circular body 2, and the two circular feed points 3 can exert a capacitive effect with the circular body 2.

It should be noted that the two circular power supply points 3 in this embodiment are also made of a sheet-like conductive material (e.g., copper foil). In order to improve the isolation of the capacitive effect and reduce the axial ratio of the capacitive effect, the positional relationship between the two circular power supply points 3 and the circular main body 2 is particularly important. Specifically, each of the circular power supply points 3 has a second center C2, and the shortest distance T1 between the second center C2 of each of the two circular power supply points 3 and the first center C1 of the circular main body 2 is required, and is preferably 1/2 or less of the radius R. In other words, the positions of the two circular power supply points 3 are adjacent to the center of the circular main body 2.

In a preferred application, the area of each of the two circular feed points 3 is preferably 1/4 or less of the area of the circular body 2 so that the capacitive effect between the two circular feed points 3 and the circular body 2 is appropriate. Furthermore, the first extension line L1 can pass through the second center C2 of one of the two circular feed points 3 and the first center C1 of the circular body 2, and the second extension line L2 can pass through the second center C2 of the other of the two circular feed points 3 and the first center C1 of the circular body 2, and the first extension line L1 and the second extension line L2 have an angle of 90 degrees therebetween.

Referring to FIG. 1 and FIG. 5, the two conductive pillars 5 in this embodiment have a cylindrical structure, and the two conductive pillars 5 are installed between the first layer 11 and the second layer 12. The two conductive pillars 5 correspond in position to the two circular feed points 3, and one of the two ends of the two conductive pillars 5 can pass through the first layer 11 and be electrically connected to the two circular feed points 3, and the other of the two ends of the two conductive pillars 5 can pass through the second layer 12 and be electrically connected to the power divider 6.

The ground element 4 in this embodiment is also a sheet-like conductive material (e.g., copper foil), and is disposed on the side of the second layer 12 facing the first layer 11. The ground element 4 has two avoidance holes H4, which correspond in position to the two conductive posts 5, so that the ground element 4 is not connected to the two conductive posts 5. Furthermore, the ground element 4 can preferably completely cover the side of the second layer 12 facing the first layer 11, but the present invention is not limited thereto.

2, 4 and 5, the power divider 6 in this embodiment may be a Wilkinson power divider and can be used to receive a signal from a beamforming integrated circuit (i.e., BFIC). Also, 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 by another of the two conductive pillars 5 ends so as to generate a 90 degree phase difference between the two circular feed points 3. Thus, the microstrip antenna 100 can generate a circularly polarized field pattern and can cooperate with the beamforming integrated circuit to realize beam control.

Note that FIG. 6 is a diagram of axial ratio data of the antenna array according to the first embodiment of the present invention, and FIG. 7 is a diagram of peak gain data of the antenna array according to the first embodiment of the present invention. From the axial ratio data, it can be seen that when the microstrip antenna 100 is in the range of 10.6 MHz to 14 MHz, the axial ratio of the microstrip antenna 100 can be 3 dB or less. Also, when the microstrip antenna 100 is in the range of 11.6 MHz to 13.6 MHz, the axial ratio of the microstrip antenna 100 can be less than 1.2 dB. Furthermore, from the peak gain data, it can be seen that when the microstrip antenna 100 is in the range of 10.9 MHz to 13 MHz, the peak gain of the microstrip antenna 100 can be greater than 2 dB. That is, the microstrip antenna 100 of the present invention not only has the advantage of a small axial ratio, but also has the effect of being able to increase the gain value.

Second Embodiment
Referring to Fig. 8, the second embodiment provides a microstrip antenna 100'. This embodiment is similar to the first embodiment, and the similarities will not be repeated here. The main differences between this embodiment and the first embodiment are as follows:

As shown in FIG. 8, in this embodiment, each of the first layer 11, the second layer 12, and the intermediate layer 13 is a circuit board, and the ground element 4 is disposed on the surface of the intermediate layer 13 facing the first layer 11. In addition, two through holes H13 are formed in the intermediate layer 13, and the two through holes H13 correspond in position to the two conductive posts 5, allowing the two conductive posts 5 to penetrate the intermediate layer 13. Note that each of the conductive posts 5 in this embodiment may also be a via hole, but the present invention is not limited to this.

Therefore, when the intermediate film 13 is a (high frequency) circuit board, the intermediate film 13 can be used as a power source or a control circuit. In addition, since the microstrip antenna 100' of this embodiment is directly formed by stacking multiple circuits in the manufacturing process, it is possible to improve manufacturing convenience compared to the microstrip antenna 100 of the first embodiment (particularly the array antenna).

Furthermore, in another embodiment of the present invention (not shown), it should be noted that the insulating carrier 1 includes a plurality of intermediate layers 13 and a plurality of ground elements 4, where a portion of the intermediate layers 13 may be a circuit board and another portion of the intermediate layers 13 may be an air medium. The ground elements 4 are disposed on the intermediate layers 13 which are circuit boards.

Of course, all of the intermediate films 13 may be circuit boards, but the present invention is not limited to this. In other words, the number of intermediate films 13 in the insulating carrier 1 and ground member 4 needs to be at least one.

[Third embodiment]
Referring to FIG. 9 to FIG. 11, the third embodiment of the present invention provides an antenna array 1000, which includes a common carrier SC and four microstrip antennas 100″ arranged on the common carrier SC. The following description will describe the structure and connection relationship of each component of the antenna array 1000.

Referring to Figures 9 and 10, the common carrier SC includes a first plate surface S1 and a second plate surface S2 facing each other, and the common carrier SC has a first direction D1 and a second direction D2 perpendicular to the first direction D1. In this embodiment, the common carrier SC can be exemplified as a plurality of insulating carriers 1 of the first embodiment or the second embodiment. That is, the common carrier SC of this embodiment is similar to the insulating carrier 1 of the first embodiment or the second embodiment, and the similarities between this embodiment and the first embodiment or the second embodiment will not be repeated here.

That is, the common carrier SC includes a first layer 11, a second layer 12, and an intermediate layer 13 between the first layer 11 and the second layer 12 (as shown in FIG. 5 or FIG. 8). Note that the surface of the first layer 11 away from the second layer 12 is defined as the first plate surface S1, and the surface of the second layer 12 away from the first layer 11 is defined as the second plate surface S2.

9 and 10, each of the microstrip antennas 100" of this embodiment can be exemplified as the microstrip antennas 100, 100' of the first or second embodiment. That is, each of the four microstrip antennas 100" of this embodiment is similar to the microstrip antennas 100, 100' of the first or second embodiment, and the similarities with this embodiment include the circular body 2, the ground element 4, the two conductive posts 5, and the power divider 6 (shown in FIG. 1), so the similarities between this embodiment and the first or second embodiment will not be repeated here. For convenience of explanation, each of the circular body 2 and the two circular feed points 3 of the microstrip antenna 100" can be further defined as an antenna structure AS.

In order to reduce the area used by the circuit 200 connected to the four microstrip antennas 100" on the common carrier SC (as shown in FIG. 11), the four microstrip antennas 100" can be configured as follows:

Specifically, the four microstrip antennas 100" are arranged at intervals on the common carrier SC, and the four microstrip antennas 100" are arranged in a matrix along the first direction D1 and the second direction D2. Furthermore, on the first plate surface S1, among the antenna structures AS along the second direction D2, any two adjacent ones have a two-fold rotational symmetry relationship. Furthermore, on the second plate surface S2, among the power distributors 6 along the first direction D1 or the second direction D2, any two adjacent ones have a mirror image relationship.

For example, as shown in FIG. 9, the first plate surface S1 has a first center line CL1 parallel to the second direction D2. The first plate surface S1 also has a first rotation point CP1 between the two microstrip antennas 100" in the first row CO1, and the first rotation point CP1 is passed by the first center line CL1 (and the connecting line of the centers of the two circular body portions 2). The first plate surface S1 also has a second rotation point CP2 between the two microstrip antennas 100" in the second row CO2, and the second rotation point CP2 is passed by the first center line CL1 (and the connecting line of the centers of the two circular body portions 2). When the two circular feed points 3 of the two microstrip antennas 100" in the first row RO1 are rotated 180 degrees with respect to the first rotation point CP1 and the second rotation point CP2, respectively, the circular feed points 3 of the two microstrip antennas 100" in the first row RO1 can be superimposed on the circular feed points 3 of the two microstrip antennas 100" in the second row RO2.

Furthermore, as shown in FIG. 10, the second plate surface S2 has two second center lines CL2 parallel to the first direction D1 and the second direction D2. The two power dividers 6 in the first row RO1 and the two power dividers 6 in the second row RO2 are arranged symmetrically with one of the two second center lines CL2 as an axis parallel to the second direction D2, and the two power dividers 6 in the first row CO1 and the two power dividers 6 in the second row CO2 are arranged symmetrically with one of the two second center lines CL2 as an axis parallel to the first direction D1.

Of course, in another embodiment of the present invention (not shown), the antenna array 1000 may include 4M microstrip antennas 100", where M is a positive integer.

Beneficial Effects of the Embodiments.
In conclusion, in the microstrip antenna provided by the present invention, "the two circular feed points are configured to generate a capacitive effect with the circular body," and "each of the two circular feed points has a second circular center, and the shortest distance between the second circular center and the first circular center is less than 1/2 of the radius," thereby enabling the microstrip antenna to effectively improve isolation and simultaneously reduce the axial ratio.

The above disclosure is merely a preferred embodiment of the present invention, and does not limit the scope of the claims of the present invention. Therefore, all equivalent technical modifications made based on the contents of the specification and accompanying drawings of the present invention are intended to be included in the scope of the claims of the present invention.

1000 Antenna Array
100, 100', 100" Microstrip antenna 1 Insulating carrier 11 First layer 12 Second layer 13 Intermediate layer H13 Through hole 2 Circular body H21 Circular through hole 3 Circular feeding point 4 Ground element H4 Interference avoidance hole 5 Conductive pillar 6 Power divider C1 First circle center C2 Second circle center R Radius T1 Minimum distance L1 First extension line L2 Second extension line SC Common carrier AS Antenna structure S1 First plate surface S2 Second plate surface D1 First direction D2 Second direction RO1 First row RO2 Second row CO1 First column CO2 Second column CP1 First rotation point CP2 Second rotation point CL1 First center line CL2 Second center line 200 Circuit

Claims (7)

1. An antenna array comprising four microstrip antennas,
Each of the four microstrip antennas has:
an insulating carrier;
a circular body portion disposed on the insulating carrier and having a first center and a radius;
two circular feeding points that are surrounded by the circular main body and are not connected to the circular main body so as to generate a capacitive effect with the circular main body, and each of the two circular feeding points has a shortest distance from the first circle center that is less than half the radius;
a ground element disposed on the insulating carrier;
a power divider electrically coupled to the two circular feed points to create a 90 degree phase difference between the two circular feed points;
Equipped with
The four microstrip antennas are arranged in a 2×2 matrix, and the circular body and the circular feed point of one of the two microstrip antennas in a first column of the 2×2 matrix are arranged with 180° rotational symmetry with respect to each other, and the circular body and the circular feed point of one of the two microstrip antennas in a second column of the 2×2 matrix are arranged with 180° rotational symmetry with respect to each other,
An antenna array characterized in that the geometric shape of one of the power dividers of the two microstrip antennas in the first column of the 2 x 2 matrix and the geometric shape of the other of the power dividers are arranged line-symmetrically with respect to a central axis of the insulating carrier perpendicular to the column direction of the 2 x 2 matrix, and the geometric shape of one of the power dividers of the two microstrip antennas in the second column of the 2 x 2 matrix and the geometric shape of the other of the power dividers are arranged line-symmetrically with respect to the central axis . The antenna array of claim 1, wherein the insulating carrier includes a first layer, a second layer, and at least one intermediate layer between the first layer and the second layer, the circular body portion is disposed on the first layer, the power divider is disposed on the second layer, and the ground element is disposed on the second layer or the at least one intermediate layer. The antenna array of claim 2, wherein each of the first layer and the second layer is a circuit board, and the at least one intermediate layer is an air medium. The antenna array of claim 2, wherein each of the first layer, the second layer, and the at least one intermediate layer is a circuit board. 5. The antenna array of claim 4, wherein the at least one intermediate layer has two through holes, and each of the microstrip antennas includes two conductive pillars, the two conductive pillars passing through the two through holes such that both ends of each of the two conductive pillars are electrically coupled to the power divider and one of the two circular feed points. The antenna array according to claim 1, wherein a first extension line passes through the second center of one of the two circular feed points and the first center of the circular body, and a second extension line passes through the second center of the other of the two circular feed points and the first center of the circular body, and the first extension line and the second extension line form an angle of 90 degrees. The antenna array of claim 1, wherein the area of each of the two circular feed points is equal to or less than 1/4 of the area of the circular main body.