TWI854694B - Antenna module - Google Patents

Abstract

An antenna module includes a feeding end, transmission lines, a ground plane and ground radiators. The transmission lines are radially connected to the feeding end. The feeding end and the transmission lines are located on a first plane. Each of the transmission lines includes a back end away from the feeding end. The ground plane is located on a second plane. A projection of the feeding end projected to the second plane is located in the ground plane. The ground radiators are located on the second plane and connected to the ground plane respectively. Each of the ground radiators includes a coupling end, a first section extended from the coupling end, a second section and a third section extended from the first section. The coupling end closes to the back end of one of the transmission lines. The third section is farther away from the coupling end than the second section. The second section is separated from the ground plane. The third section is connected to the ground plane.

Description

Antenna Module

The present invention relates to an antenna module, and in particular to an antenna module with an omnidirectional pattern.

Currently, most of the network communication products use antennas with omnidirectional patterns to facilitate users to send and receive signals. In order to have a better omnidirectional pattern, antennas are usually designed with single frequency.

With the development of technology, users' requirements for communication transmission performance have been improved. In order to further increase the frequency band range that Netcom products can cover, the number of antennas will increase accordingly. However, such a design leads to an increase in the manufacturing cost of Netcom products and an increase in the size of Netcom products. In addition, antennas are also easily affected by the configuration of surrounding components or the environment, which can easily affect the antenna pattern and reduce the user experience when using Netcom products. How to increase the frequency band range of Netcom products and at the same time have an omnidirectional radiation pattern is one of the goals that researchers in this field are working hard to study.

The present invention provides an antenna module which can generate an omnidirectional dual-frequency signal using only a single antenna module.

An antenna module of the present invention includes a feed end, a plurality of transmission lines, a ground plane, and a plurality of ground radiators. The plurality of transmission lines are radially connected to the feed end, wherein the feed end and the plurality of transmission lines are located in a first plane, and each transmission line includes an end far from the feed end. The ground plane is located in a second plane, and the projection of the feed end on the second plane is located in the ground plane. The plurality of ground radiators are located in the second plane and are respectively connected to the ground plane, and each ground radiator includes a coupling end, a first section extending from the coupling end, a second section extending from the first section, and a third section, wherein the coupling end is close to the end of one of the plurality of transmission lines, the third section is farther from the coupling end than the second section, the second section is separated from the ground plane, and the third section is connected to the ground plane. The coupling end, the first section and the third section resonate together to produce a first frequency band, and the coupling end, a part of the first section and the second section resonate together to produce a second frequency band.

In an embodiment of the present invention, the lengths of the coupling end, the first section and the third section are 0.25 times the wavelength of the first frequency band.

In an embodiment of the present invention, the length of the coupling end, the part of the first section and the second section is 0.5 times the wavelength of the second frequency band.

In an embodiment of the present invention, a projection of the end on the second plane is spaced from the coupling end.

In an embodiment of the present invention, each of the transmission lines includes a transmission section connected between the feed end and the end, and the width of the end is greater than or equal to the width of the transmission section.

In one embodiment of the present invention, the projection of the above-mentioned end on the second plane overlaps with the coupling end.

In one embodiment of the present invention, each of the transmission lines includes a transmission section connected between the feed end and the end, and the width of the end is the same as the width of the transmission section.

In an embodiment of the present invention, the distance between the second section and the ground plane is between 0.1 mm and 3 mm.

In an embodiment of the present invention, the plurality of transmission lines include four transmission lines, the plurality of ground radiators include four ground radiators, the ground plane is a quadrilateral, the four ground radiators are arranged on the four sides of the ground plane, each transmission line is an arc or a straight line, and the projection of each end on the second plane is close to a vertex of the quadrilateral.

In one embodiment of the present invention, the first frequency band is between 2400 MHz and 2500 MHz, and the second frequency band is between 5150 MHz and 5850 MHz.

Based on the above, the feed end and multiple transmission lines of the antenna module of the present invention are located in the first plane, and the ground plane is located in the second plane. Multiple transmission lines are radially connected to the feed end, and multiple ground radiators are respectively connected to the ground plane. The coupling end is close to the end of one of the multiple transmission lines, the second section is separated from the ground plane, and the third section is connected to the ground plane. The coupling end, the first section and the third section resonate together to produce a first frequency band, and the coupling end, a part of the first section and the second section resonate together to produce a second frequency band. Through such a design, the antenna module of the present invention can generate a dual-frequency signal with an omnidirectional field pattern using only a single antenna module.

FIG. 1A is a perspective view of an antenna module according to an embodiment of the present invention. FIG. 1B is a schematic view of the transmission line and circuit board of FIG. 1A. FIG. 1C is a schematic view of the ground plane and ground radiator of FIG. 1A. It should be noted that in order to clearly see the relative positions of the various components of this embodiment, the feed end 110, the transmission line 120 and the circuit board 150 of FIG. 1A are drawn in perspective.

1A to 1C, the antenna module 100 (FIG. 1A) of the present embodiment includes a feed port 110, a plurality of transmission lines 120, a circuit board 150, a ground plane 130, and a plurality of ground radiators 140. The feed port 110 and the plurality of transmission lines 120 are located in a first plane S1 (FIG. 1B). The ground plane 130 and the plurality of ground radiators 140 are located in a second plane S2 (FIG. 1C). In other words, the feed port 110, the plurality of transmission lines 120 and the ground plane 130, the plurality of ground radiators 140 are located in different planes. In addition, the first plane S1 and the second plane S2 are different planes. The first plane S1 and the second plane S2 can be upper and lower surfaces of the circuit board 150. The circuit board 150, the plurality of transmission lines 120, the ground plane 130, and the plurality of ground radiators 140 are implemented by, for example, a circuit board with copper foil on both sides.

The plurality of transmission lines 120 of the present embodiment, for example, include four transmission lines 120 and are radially connected to the feeding end 110. Specifically, each transmission line 120 includes an end 121 and a transmission section 122. The end 121 is far from the feeding end 110, and the transmission section 122 is connected to the feeding end 110 and the end 121. The projection of the feeding end 110 on the second plane S2 (FIG. 1C) is located inside the ground plane 130 (for example, the center point of the ground plane 130), and the projection of the end 121 on the second plane S2 is located outside the ground plane 130.

The plurality of ground radiators 140 of this embodiment are respectively connected to the ground plane 130. Specifically, the plurality of ground radiators 140 include, for example, four ground radiators 140, and the ground plane 130 is, for example, a quadrilateral. The four ground radiators 140 are respectively disposed on the four sides of the ground plane 130, and the projection of each end 121 on the second plane S2 (FIG. 1C) is close to a corresponding vertex A of the quadrilateral.

In addition, each ground radiator 140 includes a coupling end 141, a first section 142 extending from the coupling end 141, a second section 143 extending from the first section 142, and a third section 144, and presents appearances at different angles F. As shown in FIG. 1A and FIG. 1C, the coupling end 141 is close to the end 121 of one of the plurality of transmission lines 120, but does not touch the end 121. The third section 144 is farther from the coupling end 141 than the second section 143. The second section 143 is located between the ground plane 130 and the first section 142 and is separated from the ground plane 130. The third section 144 is connected to the vertex A (e.g., vertex A1 in FIG. 1A) of the first section 142 and the ground plane 130. In this embodiment, the distance between the second segment 143 and the ground plane 130 (the distance between the position P3 in FIG. 1A and the ground plane 130 ) is between 0.1 mm and 3 mm to achieve better impedance matching.

In this embodiment, the coupling end 141, the first section 142 and the third section 144 resonate together to produce a first frequency band, and the coupling end 141, a part of the first section 142 and the second section 143 resonate together to produce a second frequency band. In detail, the signal is input from the feed end 110, and the plurality of transmission lines 120 divide and transmit the signal to the end 121 of each transmission line 120. The signal is coupled to the coupling end 141 of the grounded radiator 140 through the transmission line 120, and resonates through the grounded radiator 140 to produce a plurality of frequency bands.

As shown in FIG. 1A , the signal resonates together to produce a first frequency band along the path of the coupling end 141, the first section 142 and the third section 144 (positions P1, P2, P4, P5). The signal may also resonate together to produce a second frequency band along the path of the coupling end 141, a part of the first section 142 and the second section 143 (positions P1, P2, P3). The length of the coupling end 141, the first section 142 and the third section 144 is 0.25 times the wavelength of the first frequency band. The length of the coupling end 141, a part of the first section 142 and the second section 143 is 0.5 times the wavelength of the second frequency band. The first frequency band is, for example, between 2400MHz-2500MHz (2.4G), and the second frequency band is, for example, between 5150MHz-5850MHz (5G).

Through the above design, the antenna module 100 (FIG. 1A) of the present embodiment can resonate with the first frequency band (i.e., 2.4 GHz) and the second frequency band (i.e., 5 GHz) by using only a single module. Therefore, the frequency band coverage of the antenna module 100 of the present embodiment is large, and can be applied to WI-FI products such as cameras, routers, and wireless base stations without increasing the manufacturing cost. In addition, since the transmission line 120 and the ground radiator 140 are both arranged in geometric shapes, the radiation pattern of the frequency band resonated by the antenna module 100 of the present embodiment is an omnidirectional pattern.

In addition, the path of the antenna module 100 (FIG. 1A) of the present embodiment resonates the first frequency band through the coupling end 141, the first section 142 and the third section 144 (positions P1, P2, P4, P5), and the path of the second frequency band resonates through the coupling end 141, a part of the first section 142 and the second section 143 (positions P1, P2, P3). When the center frequency of the first frequency band is to be adjusted, only the length of the third section 144 or the length of a part of the first section 142 (positions P2 to P4) can be adjusted. When the center frequency of the second frequency band is to be adjusted, only the length of the second section 143 can be adjusted. In other words, the two antenna modes of the antenna module 100 of the present embodiment can be adjusted separately without interfering with each other.

It should be noted that the number of transmission lines 120 and ground radiators 140 in this embodiment is four and they are respectively arranged in four directions. However, in other embodiments, the number of transmission lines 120 and ground radiators 140 can be greater and they can be symmetrical to each other. The present invention is not limited to this.

In addition, each transmission line 120 of this embodiment has an arc appearance. According to simulation, when the transmission line 120 is an arc, the signal loss is less. However, in other embodiments, each transmission line 120 may also have a straight appearance, and the present invention is not limited thereto.

FIG2 is a perspective schematic diagram of an antenna module according to another embodiment of the present invention. Referring to FIG2 , the antenna module 100′ of this embodiment is similar in structure to the antenna module 100 (FIG. 1A). The difference between the two is that, as shown in FIG1A , the projection of the end 121 of the transmission line 120 of the antenna module 100 on the second plane S2 (FIG. 1C) is spaced from the coupling end 141, and the width of the end 121 is greater than the width of the transmission section 122. Such a design can increase the coupling amount of the signal. As shown in FIG2 , the projection of the end 121′ of the transmission line 120′ of the antenna module 100′ on the second plane S2 overlaps with the coupling end 141. Since the distance between the end 121′ of the transmission line 120′ and the coupling end 141 is closer than the distance between the end 121 of the transmission line 120 and the coupling end 141, the width of the end 121′ of the present embodiment can be adjusted to be the same as the width of the transmission section 122 while still having a good coupling amount.

FIG3 is a radiation pattern diagram of the antenna module of FIG1 in the X-Y plane. Referring to FIG3, the antenna module 100 has a good omnidirectional radiation pattern when the frequency is 2.45 GHz (within the first frequency band) and 5.47 GHz (within the second frequency band). In other words, the antenna module 100 of this embodiment has a good omnidirectional radiation pattern in the first frequency band and the second frequency band of resonance.

FIG4 is a graph showing the relationship between the frequency and S11 of the antenna module of FIG1. Referring to FIG4, when the antenna module 100 of this embodiment resonates in the first frequency band and the second frequency band, S11 is less than -7.5 dB. That is, the antenna module 100 of this embodiment resonates in both the first frequency band and the second frequency band with good performance.

In summary, the feed end and multiple transmission lines of the antenna module of the present invention are located in the first plane, and the ground plane is located in the second plane. Multiple transmission lines are radially connected to the feed end, and multiple ground radiators are respectively connected to the ground plane. The coupling end is close to the end of one of the multiple transmission lines. The second section is separated from the ground plane, and the third section is connected to the ground plane. The coupling end, the first section and the third section resonate together to produce a first frequency band, and the coupling end, a part of the first section and the second section resonate together to produce a second frequency band. The length of the coupling end, the first section and the third section is 0.25 times the wavelength of the first frequency band. The length of the coupling end, a part of the first section and the second section is 0.5 times the wavelength of the second frequency band. Through such a design, the antenna module of the present invention can generate a dual-band signal with an omnidirectional pattern using only a single antenna module, which has good performance and is less susceptible to the influence of surrounding components or environment on the antenna efficiency and pattern.

100, 100’: antenna module 110: feed end 120, 120’: transmission line 121, 121’: end 122: transmission section 130: ground plane 140: ground radiator 141: coupling end 142: first section 143: second section 144: third section 150: circuit board A, A1: vertex P1, P2, P3, P4, P5: position S1: first plane S2: second plane X-Y-Z: rectangular coordinates

FIG. 1A is a perspective schematic diagram of an antenna module according to an embodiment of the present invention. FIG. 1B is an external schematic diagram of the transmission line and circuit board of FIG. 1A. FIG. 1C is an external schematic diagram of the ground plane and ground radiator of FIG. 1A. FIG. 2 is a perspective schematic diagram of an antenna module according to another embodiment of the present invention. FIG. 3 is a radiation field diagram of the antenna module of FIG. 1 in the X-Y plane. FIG. 4 is a relationship diagram between the frequency and S11 of the antenna module of FIG. 1.

100: Antenna module

110: Feeding end

120: Transmission line

121: The end

122: Transmission segment

130: Ground contact surface

140: Ground Radiator

141: coupling end

142: First paragraph

143: Second paragraph

144: The third paragraph

150: Circuit board

A, A1: Vertex

P1, P2, P3, P4, P5: Location

X-Y-Z: Cartesian coordinates

Claims (10)

An antenna module includes: a feed end; a plurality of transmission lines radially connected to the feed end, the feed end and the transmission lines are located in a first plane, each of the transmission lines includes an end far away from the feed end; a ground plane located in a second plane, the projection of the feed end on the second plane is located in the ground plane; and a plurality of ground radiators located in the second plane and respectively connected to the ground plane, each of the ground radiators includes a coupling end, a first section extending from the coupling end, a second section extending from the first section, and a third section, the coupling end is close to the end of one of the transmission lines, the third section is farther away from the coupling end than the second section, the second section is separated from the ground plane, and the third section is connected to the ground plane, The coupling end, the first section and the third section resonate together to produce a first frequency band, and the coupling end, a part of the first section and the second section resonate together to produce a second frequency band. An antenna module as described in claim 1, wherein the lengths of the coupling end, the first section and the third section are 0.25 times the wavelength of the first frequency band. An antenna module as described in claim 1, wherein the length of the coupling end, the portion of the first section and the second section is 0.5 times the wavelength of the second frequency band. An antenna module as described in claim 1, wherein a projection of the end on the second plane is spaced from the coupling end. An antenna module as described in claim 4, wherein each transmission line includes a transmission segment connected between the feed end and the end, and the width of the end is greater than or equal to the width of the transmission segment. An antenna module as described in claim 1, wherein a projection of the end onto the second plane overlaps with the coupling end. An antenna module as described in claim 6, wherein each transmission line includes a transmission segment connected between the feed end and the end, and the width of the end is the same as the width of the transmission segment. An antenna module as described in claim 1, wherein the distance between the second section and the ground plane is between 0.1 mm and 3 mm. An antenna module as described in claim 1, wherein the transmission lines include four transmission lines, the ground radiators include four ground radiators, the ground plane is a quadrilateral, the four ground radiators are arranged on the four sides of the ground plane, each of the transmission lines is an arc or a straight line, and the projection of each end on the second plane is close to a vertex of the quadrilateral. The antenna module as described in claim 1, wherein the first frequency band is between 2400 MHz and 2500 MHz, and the second frequency band is between 5150 MHz and 5850 MHz.

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