CN111384588A - Multi-frequency antenna - Google Patents

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-frequency antenna, in particular to a multi-frequency antenna operable in multiple frequency bands.

Background technique

In recent years, in order to meet consumers' demands for image quality and product appearance, the product design of communication devices has gradually developed towards a trend of narrow bezels. However, under the appearance design of the narrow frame, the area available for arranging the antenna element in the communication device becomes less and less. In addition, as more and more recording-related components (eg, camera lens, flash) are added to the top edge of the communication device, the available antenna layout area of the communication device is greatly limited.

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

SUMMARY OF THE INVENTION

The present invention provides a multi-frequency antenna, which can configure antenna elements in a limited antenna layout area, and enables the operating frequency band of the antenna elements to reach the widest frequency range.

Embodiments of the present invention provide a multi-frequency antenna. The multi-frequency antenna includes a ground plane and an antenna element. The antenna element includes a first radiation portion and a second radiation portion. The first end of the first radiation part is coupled to the feeding point, and the second end of the first radiation part is the first open end. The first end of the second radiation portion is coupled to the ground plane, and the second end of the second radiation portion is the second open end. The second radiating part is electrically disconnected from the first radiating part, and there is a coupling distance between the second radiating part and the first radiating part. The antenna element operates in the first frequency band through the first radiating part, and operates in the second frequency band through the second radiating part, and the frequency of the first frequency band is lower than the frequency of the second frequency band.

Based on the above, in various embodiments of the present invention, the antenna element of the multi-frequency antenna includes a first radiating portion and a second radiating portion that are not electrically connected to each other, and there is a coupling distance between the second radiating portion and the first radiating portion . By keeping the first radiating portion and the second radiating portion in an electrically floating state, serious interference between the first frequency band and the second frequency band of the antenna element can be avoided. Since there is no need to consider the situation of frequency band interference, the coupling distance between the first radiating portion and the second radiating portion can be shortened as much as possible, so as to save the layout area of the antenna. Therefore, in the limited antenna layout area within the communication device. The first radiating portion and the second radiating portion with a predetermined size can be configured, so that the operating frequency band of the antenna element can reach the widest frequency bandwidth range, thereby improving the performance of the antenna element.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

Description of drawings

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

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

2B is a schematic cross-sectional view illustrating the multi-frequency antenna 200 of FIG. 2A in the direction of section line B-B' according to an embodiment of the present invention;

FIG. 2C is a schematic diagram illustrating the overlapping area of the first radiation portion 110 and the third radiation portion 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 still another embodiment of the present invention.

Description of reference numerals

100, 200, 300: Multi-frequency antenna

101: Ground plane

102, 202: Antenna elements

103: Substrate

104, 105, 106: Matching components

110: First Radiation Department

111: First Section

112: Second Section

113: Third Section

114: Fourth Section

115: Fifth Section

120: Second Radiation Department

121: Sixth Section

122: Section 7

130: Third Radiation Department

1031: First Surface

1032: Second Surface

A1: first area

A2: Second area

D1: Coupling spacing

E1: open end

E2: open end

FP: Feed Point

L: first length

W: first width

W': the first spacing

Detailed ways

The term "coupled (or connected)" as used throughout this specification (including the claims) may refer to any direct or indirect means of connection. For example, if the text describes that a first device is coupled (or connected) to a second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be connected to the second device through other devices or indirectly connected to the second device by a connecting means. In addition, where possible, elements/components/steps using the same reference numerals in the drawings and embodiments represent the same or similar parts. Elements/components/steps that use the same reference numerals or use the same terminology in different embodiments may refer to relative descriptions of each other.

FIG. 1 is a schematic top view of a multi-frequency antenna 100 according to an embodiment of the present invention. Referring to FIG. 1 , the multi-frequency antenna 100 includes a ground plane 101 and an antenna element 102 . According to design requirements, the multi-frequency antenna 100 can be applied to notebook computers, Bluetooth communication devices, smart phones, tablet computers or other wireless transceiver devices. In addition, the multi-frequency antenna 100 further has a substrate 103 . The substrate 103 can be used to carry the antenna element 102 and serve as an antenna layout area. The antenna element 102 may be a Planar Antenna, and the substrate 103 may be a FR-4 substrate (Flame Retardant-4 Substrate) or other dielectric substrates (Dielectric Substrate).

The antenna element 102 may include a first radiation portion 110 and a second radiation portion 120 . The first end of the first radiation portion 110 is coupled to the feeding point FP, and the second end of the first radiation portion 110 is the open end E1. The first end of the second radiation portion 120 is coupled to the ground plane 101 , and the second end of the second radiation portion 120 is the open end E2 . The second radiating part 120 and the first radiating part 110 are not electrically connected, and there is a coupling distance D1 between the second radiating part 120 and the first radiating part 110 .

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

In this embodiment, the first end of the second radiating portion 120 can be coupled to the ground plane 101 via the matching element 104 to adjust the impedance matching of the antenna element 102 in the second frequency band and shorten the length of the second radiating portion 120 . resonance path. In addition, since the second radiating portion 120 and the first radiating portion 110 are not electrically connected, but remain in an electrically floating state, the first resonance mode and the second resonance mode can be mutually impact is minimized.

Referring to FIG. 1 again, the first radiating portion 110 includes a first section 111 , a second section 112 , a third section 113 , and a fourth section that are connected in series with each other in sequence from the feeding point FP to the open end E1 114 and the fifth section 115. The longitudinal direction of the second segment 112 and the longitudinal direction of the fourth segment 114 are both parallel to the first direction (eg, the 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 (eg, the Y direction), and the first direction is perpendicular to the second direction direction. It should be noted that in FIG. 1 , the longitudinal direction of the first segment 111 is parallel to the Y direction as an example for illustration. In other embodiments, the longitudinal direction of the first section 111 may also be parallel to the X direction, that is, the length of the first section 111 in the X direction may be designed to be greater than the length of the first section 111 in the Y direction.

As shown in FIG. 1 , the second radiating portion 120 includes a sixth section 121 and a seventh section 122 that are connected in series with each other. The longitudinal direction of the seventh segment 122 is parallel to the first direction (eg, the X direction), and the longitudinal direction of the sixth segment 121 is parallel to the second direction (eg, the Y direction). In other words, the longitudinal direction of the sixth segment 121 is parallel to the longitudinal direction of the third segment 113 , and the longitudinal direction of the seventh segment 122 is parallel to the longitudinal direction of the second segment 112 .

FIG. 2A is a schematic top view of a multi-frequency antenna 200 according to another embodiment of the present invention. The multi-frequency 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 (eg, 65 mm) and a first width W (eg, 10 mm). The antenna element 202 can operate in the first frequency band through the first radiating part 110 and operate in the second frequency band through the second radiating part 120 . In this embodiment, the first frequency band may include a frequency band between 704 MHz and 960 MHz, and the second frequency band may include a frequency band between 1710 MHz and 2170 MHz. In other embodiments, the frequency ranges of the first frequency band and the second frequency band can 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 communication frequency band of Long Term Evolution (LTE).

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

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

In addition, the position of the third radiating part 130 in the Y direction can be set at a position away from the ground plane 101 , so as to improve the coupling efficiency between the third radiating part 130 and the first radiating part 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 and the ground plane 101 have a first distance W'. In this embodiment, the first distance W' between the third radiation portion 130 and the ground plane 101 is equal to half of the first width W (ie, W'=W/2). In other embodiments, the first spacing W' may be greater than or equal to one-half of the first width W (ie, W'>W/2).

The position of the third radiating part 130 in the X direction can be set close to the feeding point FP, so as to improve the coupling efficiency between the third radiating part 130 and the first radiating part 110 . For example, FIG. 2C is a schematic diagram illustrating the overlapping area of the first radiation portion 110 and the third radiation portion 130 of FIG. 2A in the Z direction according to an embodiment of the present invention. As shown in FIG. 2C , the orthographic projection of the first radiation portion 110 on the substrate 103 (orthographic projection along the Z direction) and the orthographic projection of the third radiation portion 130 on the substrate 103 (orthographic projection along the Z direction) may overlap The area 140, the overlapping area 140 is located on the right side of the third radiating part 130, that is, close to the feeding point FP. In addition, the overlapping area 140 has a first area A1, and the orthographic projection of the third radiation portion 130 on the substrate 103 has a second area A2, and the first area A1 is smaller than the second area A2.

FIG. 3 is a schematic top view of a multi-frequency antenna 300 according to yet another embodiment of the present invention. The difference between the multi-frequency antenna 300 of FIG. 3 and the multi-frequency antenna 200 of FIG. 2A is that the third radiating part 130 and the first radiating part 110 of FIG. The coupling efficiency between the three radiation parts 130 and the first radiation part 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 part 110 can be coupled to the feeding point FP through the matching element 105 , and the first end of the first radiating part 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 part 110 ), so that the antenna element 202 can reach the 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 via the matching element 104 , the matching element 104 can be used to adjust the antenna element 202 in the second frequency band (the frequency band generated by the second radiating portion 120 ) impedance matching, so that the antenna element 202 can reach the bandwidth set by 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 an inductor. Therefore, by arranging the matching elements 104 , 105 , 106 at the feeding point FP and its surroundings, the antenna element 202 can reach a preset frequency bandwidth, thereby effectively improving the overall performance of the antenna element 202 .

To sum up, in various embodiments of the present invention, the antenna element of the multi-frequency antenna can operate in three communication frequency bands respectively through the first radiating portion, the second radiating portion and the third radiating portion. By keeping the first radiating part and the second radiating part in an electrically floating state, and also maintaining the electrically floating state between the first radiating part and the third radiating part, it is possible to avoid A situation in which the low frequency band and the high frequency band of an antenna element interfere with each other. Since there is no need to consider the situation of frequency band interference, the coupling distance between the first radiating portion and the second radiating portion can be shortened as much as possible, so as to save the layout area of the antenna. In addition, by disposing the third radiating portion and the first radiating portion on opposite sides of the substrate of the multi-frequency antenna, the layout space of the antenna element can be effectively saved. Therefore, in the limited antenna layout space in the communication device, the first radiating portion, the second radiating portion and the third radiating portion with preset sizes can be configured, so that the operating frequency band of the antenna element can reach the widest frequency bandwidth, and further Improve the performance of the antenna element.

Although the present invention has been disclosed above with examples, it is not intended to limit the present invention. Any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be subject to what is defined in the claims.

Claims (12)

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.

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