CN111384588A

CN111384588A - Multi-frequency antenna

Info

Publication number: CN111384588A
Application number: CN201811609653.4A
Authority: CN
Inventors: 张琨盛
Original assignee: Acer Inc
Current assignee: Acer Inc
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2020-07-07
Anticipated expiration: 2038-12-27
Also published as: CN111384588B

Abstract

The invention provides a multi-frequency antenna, which comprises a ground plane and an antenna element. The antenna element comprises a first radiating part and a second radiating part. The first end of the first radiation part is coupled to the feed-in point, and the second end of the first radiation part is a first open end. The first end of the second radiating part is coupled to the ground plane, and the second end of the second radiating part is a second open end. The second radiation part is not electrically connected with the first radiation part, and a coupling space is arranged between the second radiation part and the first radiation part. The antenna element is operated in a first frequency band through the first radiation part and operated in a second frequency band through the second radiation part, and the frequency of the first frequency band is lower than that of the second frequency band.

Description

Multi-frequency antenna

Technical Field

The present invention relates to a multi-band antenna, and more particularly, to a multi-band antenna capable of operating in multiple frequency bands.

Background

In recent years, in order to satisfy consumer demands for image quality and product appearance, product designs of communication devices are gradually developing toward narrow frames. However, in the design of the narrow bezel, the area available for disposing the antenna element in the communication device is less and less. In addition, as more and more video-related components (e.g., camera lens, flash) are added to the Top of the communication device (Top Edge), the usable antenna layout area in the communication device is further limited.

Therefore, how to properly arrange the antenna elements in a limited layout area without affecting the communication quality is an important issue in the field of antenna design.

Disclosure of Invention

The invention provides a multi-frequency antenna, which can be used for configuring antenna elements in a limited antenna layout area and enabling the operating frequency range of the antenna elements to reach the widest frequency width range.

The embodiment of the invention provides a multi-frequency antenna. The multi-frequency antenna comprises a ground plane and an antenna element. The antenna element comprises a first radiating part and a second radiating part. The first end of the first radiation part is coupled to the feed-in point, and the second end of the first radiation part is a first open end. The first end of the second radiating part is coupled to the ground plane, and the second end of the second radiating part is a second open end. The second radiation part is not electrically connected with the first radiation part, and a coupling space is arranged between the second radiation part and the first radiation part. The antenna element is operated in a first frequency band through the first radiation part and operated in a second frequency band through the second radiation part, and the frequency of the first frequency band is lower than that of the second frequency band.

In view of the above, in the embodiments of the present invention, the antenna element of the multi-frequency antenna includes the first radiation portion and the second radiation portion that are not electrically connected to each other, and the second radiation portion and the first radiation portion have a coupling gap therebetween. By maintaining the first radiating portion and the second radiating portion in an electrically floating (floating) state, the first frequency band and the second frequency band of the antenna element can be prevented from generating serious interference. Because the frequency band interference is not needed to be considered, the coupling distance between the first radiation part and the second radiation part can be shortened as much as possible, so as to save the layout area of the antenna. Therefore, in a limited antenna layout area within the communication device. The first radiating part and the second radiating part with preset sizes can be configured, so that the operating frequency band of the antenna element can reach the widest frequency range, and the efficiency of the antenna element is further improved.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic top view of a multi-frequency antenna according to an embodiment of the invention;

fig. 2A is a schematic top view of a multi-frequency antenna according to another embodiment of the invention;

fig. 2B is a schematic cross-sectional view of the multi-frequency antenna 200 of fig. 2A along a sectional line B-B', according to an embodiment of the invention;

fig. 2C is a schematic diagram illustrating an overlapping area of the first radiation part 110 and the third radiation part 130 of fig. 2A in the Z direction according to an embodiment of the present invention;

fig. 3 is a schematic top view of a multi-frequency antenna according to another embodiment of the invention.

Description of the reference numerals

100. 200 and 300: multi-frequency antenna

101: ground plane

102. 202: antenna element

103: substrate

104. 105, 106: matching element

110: a first radiation part

111: the first section

112: second section

113: third section

114: the fourth section

115: the fifth section

120: second radiation part

121: the sixth section

122: the seventh section

130: third radiation part

1031: first surface

1032: second surface

A1: first area

A2: second area

D1: coupling pitch

E1: open end

E2: open end

FP: feed-in point

L: first length

W: first width

W': first interval

Detailed Description

The term "coupled" as used throughout this specification, including the claims, may refer to any direct or indirect connection. For example, if a first device couples (or connects) to a second device, it should be construed that the first device may be directly connected to the second device or the first device may be indirectly connected to the second device through some other device or some connection means. Further, wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts. Elements/components/steps in different embodiments using the same reference numerals or using the same terms may be referred to one another in relation to the description.

Fig. 1 is a schematic top view of a multi-frequency antenna 100 according to an embodiment of the invention. Referring to fig. 1, a multi-band antenna 100 includes a ground plane 101 and an antenna element 102. According to design requirements, the multi-band antenna 100 can be applied to a notebook computer, a bluetooth communication device, a smart phone, a tablet computer, or other wireless transceiver devices. Further, the multiband antenna 100 further has a substrate 103. The substrate 103 may be used to carry the antenna elements 102 and serve as an antenna layout area. The Antenna element 102 may be a Planar Antenna (Planar Antenna) and the Substrate 103 may be an FR-4 Substrate (frame repeat-4 Substrate) or other Dielectric Substrate (Dielectric Substrate).

The antenna element 102 may include a first radiating portion 110 and a second radiating portion 120. The first end of the first radiating portion 110 is coupled to the feed point FP, and the second end of the first radiating portion 110 is an open end E1. The first end of the second radiating portion 120 is coupled to the ground plane 101, and the second end of the second radiating portion 120 is an open end E2. The second radiation portion 120 is electrically disconnected from the first radiation portion 110, and a coupling distance D1 is formed between the second radiation portion 120 and the first radiation portion 110.

In operation, antenna element 102 may receive a feed signal provided by a transceiver (not shown) of multi-frequency antenna 100 through feed point FP. For example, the feeding point FP disposed on the first radiation portion 110 may be electrically connected to the transceiver of the multi-frequency antenna 100 through a coaxial cable, a conductive elastic piece, or a thimble, so that the first radiation portion 110 may receive a feeding signal from the transceiver and generate a first resonant mode. Meanwhile, through the coupling distance D1 between the first radiation part 110 and the second radiation part 120, the feeding signal can be further coupled from the feeding point FP of the first radiation part 110 to the second radiation part 120, so that the second radiation part 120 generates a second resonance mode. The first resonance mode and the second resonance mode may correspond to a first frequency band and a second frequency band, respectively. Therefore, the antenna element 102 can operate in the first frequency band through the first radiating portion 110 and operate in the second frequency band through the second radiating portion 120.

In this embodiment, the first end of the second radiating portion 120 may be coupled to the ground plane 101 through the matching element 104, so as to adjust the impedance matching of the antenna element 102 in the second frequency band and shorten the resonant path formed by the second radiating portion 120. In addition, since the second radiation portion 120 is not electrically connected to the first radiation portion 110, but remains in an electrically floating (floating) state, the mutual influence between the first resonance mode and the second resonance mode can be minimized.

Referring to fig. 1 again, the first radiation portion 110 sequentially includes a first section 111, a second section 112, a third section 113, a fourth section 114 and a fifth section 115 connected in series from the feed point FP to the open end E1. The long side direction of the second segment 112 and the long side direction of the fourth segment 114 are both parallel to the first direction (e.g., X direction). The longitudinal direction of the first segment 111, the longitudinal direction of the third segment 113, and the longitudinal direction of the fifth segment 115 are all parallel to the second direction (for example, the Y direction), and the first direction is perpendicular to the second direction. It should be noted that fig. 1 illustrates the long side direction of the first segment 111 being parallel to the Y direction. In other embodiments, the long side direction of the first segment 111 may also be parallel to the X direction, that is, the length of the first segment 111 in the X direction may be designed to be greater than the length of the first segment 111 in the Y direction.

As shown in fig. 1, the second radiation portion 120 includes a sixth section 121 and a seventh section 122 connected in series. The long side direction of the seventh segment 122 is parallel to the first direction (for example, X direction), and the long side direction of the sixth segment 121 is parallel to the second direction (for example, Y direction). In other words, the long side direction of the sixth section 121 is parallel to the long side direction of the third section 113, and the long side direction of the seventh section 122 is parallel to the long side direction of the second section 112.

Fig. 2A is a schematic top view of a multi-frequency antenna 200 according to another embodiment of the invention. The multi-band antenna 200 includes a ground plane 101, an antenna element 202 and a substrate 103, wherein the substrate 103 may have a first length L (e.g. 65mm) and a first width W (e.g. 10 mm). The antenna element 202 can operate in a first frequency band through the first radiating portion 110 and operate in a second frequency band through the second radiating portion 120. In this embodiment, the first frequency band may comprise a frequency band between 704MHz and 960MHz, and the second frequency band may comprise a frequency band between 1710MHz and 2170 MHz. In other embodiments, the frequency ranges of the first frequency band and the second frequency band may be adjusted according to other design requirements. For example: the operating frequency band of the antenna element 202 may be designed to cover the entire Long Term Evolution (LTE) communication frequency band.

Unlike the embodiment of fig. 1, the antenna element 202 of fig. 2A further includes a third radiating portion 130. The third radiation portion 130 and the first radiation portion 110 are respectively disposed on two opposite sides of the substrate 103, and there is no electrical connection between the third radiation portion 130 and the first radiation portion 110. For example, fig. 2B is a schematic cross-sectional view of the multi-band antenna 200 of fig. 2A along a sectional line B-B', according to an embodiment of the invention. As shown in fig. 2B, the first radiation part 110 and the second radiation part 120 may be disposed on the first surface 1031 of the substrate 103, and the third radiation part 130 may be disposed on the second surface 1032 of the substrate 103.

The feeding signal of the multi-band antenna 200 can be coupled to the third radiation portion 130 from the feeding point FP of the first radiation portion 110, so that the third radiation portion 130 generates a third resonance mode corresponding to a third frequency band. In this embodiment, the antenna element 202 can operate in the third frequency band through the third radiating portion 130, and the frequency of the third frequency band can be higher than the frequency of the second frequency band of the second radiating portion 120. For example: the third frequency band may comprise a frequency band between 2.3GHz and 2.7 GHz. Therefore, the antenna element 202 can be operated in a low frequency band (first frequency band) and two high frequency bands (second frequency band, third frequency band) by the first radiating portion 110, the second radiating portion 120 and the third radiating portion 130, respectively.

In addition, the position of the third radiation portion 130 in the Y direction may be disposed at a position away from the ground plane 101, so as to improve the coupling efficiency between the third radiation portion 130 and the first radiation portion 110. For example, as shown in fig. 2A, the short side of the substrate 103 has a first width W, and the third radiating portion 130 has a first distance W from the ground plane 101. In the present embodiment, the first spacing W 'between the third radiating element 130 and the ground plane 101 is equal to one half of the first width W (i.e., W' ═ W/2). In other embodiments, the first pitch W 'may be greater than or equal to one-half of the first width W (i.e., W' > W/2).

The position of the third radiation portion 130 in the X direction may be disposed near the feed point FP to improve the coupling efficiency between the third radiation portion 130 and the first radiation portion 110. For example, fig. 2C is a schematic diagram illustrating an overlapping area of the first radiation part 110 and the third radiation part 130 of fig. 2A in the Z direction according to an embodiment of the invention. As shown in fig. 2C, an orthogonal projection (orthogonal projection in the Z direction) of the first radiation part 110 on the substrate 103 and an orthogonal projection (orthogonal projection in the Z direction) of the third radiation part 130 on the substrate 103 may form an overlapping region 140, and the overlapping region 140 is located at the right side of the third radiation part 130, that is, near the feed point FP. Further, the overlapping region 140 has a first area a1, and an orthogonal projection of the third radiation part 130 on the substrate 103 has a second area a2, and the first area a1 is smaller than the second area a 2.

Fig. 3 is a schematic top view of a multi-frequency antenna 300 according to still another embodiment of the invention. The difference between the multi-frequency antenna 300 of fig. 3 and the multi-frequency antenna 200 of fig. 2A is that there are more overlapping portions of the third radiation portion 130 and the first radiation portion 110 of fig. 3 in the Z direction, so that the coupling efficiency between the third radiation portion 130 and the first radiation portion 110 is further improved. In addition, the multi-frequency antenna 300 of fig. 3 further includes a matching element 105 and a matching element 106. As shown in fig. 3, the first end of the first radiating portion 110 may be coupled to the feed point FP through the matching element 105, and the first end of the first radiating portion 110 is further coupled to the ground plane 101 through the matching element 106. The matching element 105 and the matching element 106 can be used to adjust the impedance matching of the antenna element 202 in the first frequency band (the frequency band generated by the first radiating portion 110), so that the antenna element 202 reaches the frequency bandwidth set by the first frequency band.

Similarly, since the first end of the second radiating portion 120 is coupled to the ground plane 101 through the matching element 104, the matching element 104 can be used to adjust the impedance matching of the antenna element 202 in the second frequency band (the frequency band generated by the second radiating portion 120), so that the antenna element 202 reaches the set bandwidth of the second frequency band. In this embodiment, the matching element 104 and the matching element 105 may be capacitors, and the matching element 106 may be inductors. Therefore, by disposing the

matching devices

104, 105, and 106 at the feed point FP and around the feed point FP, the antenna element 202 can reach a predetermined bandwidth, thereby effectively improving the overall performance of the antenna element 202.

In summary, in the embodiments of the present invention, the antenna element of the multi-band antenna can be operated in three communication bands through the first radiation portion, the second radiation portion and the third radiation portion, respectively. By maintaining the first radiating portion and the second radiating portion in an electrically floating (floating) state and also maintaining the first radiating portion and the third radiating portion in an electrically floating (floating) state, the situation that the low frequency band and the high frequency band of the antenna element interfere with each other can be avoided. Because the frequency band interference is not needed to be considered, the coupling distance between the first radiation part and the second radiation part can be shortened as much as possible, so as to save the layout area of the antenna. In addition, the third radiation part and the first radiation part are respectively arranged on two opposite surfaces of the substrate of the multi-frequency antenna, so that the layout space of the antenna elements can be effectively saved. Therefore, in the limited antenna layout space in the communication device, the first radiation part, the second radiation part and the third radiation part with preset sizes can be configured, so that the operation frequency band of the antenna element can reach the widest frequency bandwidth range, and the efficiency of the antenna element is further improved.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A multi-frequency antenna, comprising:

a ground plane; and

an antenna element, comprising:

a first radiation part, a first end of which is coupled to the feed point, and a second end of which is a first open end; and

a second radiation part, a first end of which is coupled to the ground plane, a second end of which is a second open end, wherein the second radiation part is electrically disconnected from the first radiation part, and a coupling space is provided between the second radiation part and the first radiation part,

the antenna element is operated in a first frequency band through the first radiating part and operated in a second frequency band through the second radiating part, and the frequency of the first frequency band is lower than that of the second frequency band.

2. The multi-frequency antenna of claim 1, wherein the first frequency band comprises a frequency band between 704MHz and 960MHz, and the second frequency band comprises a frequency band between 1710MHz and 2170 MHz.

3. The multi-band antenna of claim 1, wherein the first radiating portion sequentially comprises a first segment, a second segment, a third segment, a fourth segment and a fifth segment connected in series from the feeding point to the first open end, a long side direction of the second segment and a long side direction of the fourth segment are both parallel to a first direction, a long side direction of the third segment and a long side direction of the fifth segment are both parallel to a second direction, and the first direction is perpendicular to the second direction.

4. The multi-frequency antenna according to claim 3, wherein the second radiation portion comprises a sixth section and a seventh section connected in series, a long side direction of the sixth section is parallel to a long side direction of the third section, and a long side direction of the seventh section is parallel to a long side direction of the second section.

5. The multi-frequency antenna of claim 1, wherein the multi-frequency antenna has a substrate, the multi-frequency antenna further comprising:

and a third radiating portion electrically disconnected from the first radiating portion, wherein the third radiating portion and the first radiating portion are respectively disposed on two opposite sides of the substrate, wherein the antenna element is operated in a third frequency band through the third radiating portion, and the frequency of the third frequency band of the third radiating portion is higher than the frequency of the second frequency band of the second radiating portion.

6. The multi-frequency antenna of claim 5, wherein the third frequency band comprises a frequency band between 2.3GHz and 2.7 GHz.

7. The multi-frequency antenna of claim 5, wherein an orthographic projection of the first radiating portion on the substrate and an orthographic projection of the third radiating portion on the substrate form an overlapping area, the overlapping area has a first area, an orthographic projection of the third radiating portion on the substrate has a second area, the first area is smaller than the second area, and the feed point is adjacent to the overlapping area.

8. The multi-frequency antenna of claim 5, wherein the substrate has a short side with a first width, the third radiating portion has a first spacing from the ground plane, the first spacing being greater than or equal to one-half of the first width.

9. The multi-frequency antenna of claim 1, wherein the first end of the first radiating portion is coupled to the feed point via a first matching element, and the first end of the first radiating portion is coupled to the ground plane via a second matching element, the first and second matching elements being configured to adjust an impedance matching of the antenna element at the first frequency band.

10. The multi-frequency antenna of claim 1, wherein the first end of the second radiating portion is coupled to the ground plane via a third matching element, the third matching element configured to adjust an impedance matching of the antenna element at the second frequency band.

11. The multi-frequency antenna of claim 9, wherein the first matching element is a capacitor and the second matching element is an inductor.

12. The multi-frequency antenna of claim 10, wherein the third matching element is a capacitor.