CN104183898A - Communication device - Google Patents

Abstract

A communication device includes a grounding element and an antenna element. The antenna element comprises a metal part which is bent for multiple times and approximately forms a ring structure with a gap. The gap is between a first opening end and a second opening end of the metal part. The metal part extends along one edge of the grounding element and does not overlap with the grounding element. The antenna element has a feed point. A first portion of the metal portion is between the feed point and the first open end, and a second portion of the metal portion is between the feed point and the second open end. The feed point, the first open end and the second open end face or are adjacent to the edge of the grounding element. The length of the second portion of the metal part is between 0.1 and 0.4 times the length of the first portion of the metal part. The communication device of the present invention can achieve a low-profile appearance of an antenna element.

Description

communication device

technical field

The present invention relates to a communication device, in particular to a communication device including a low-profile multi-band antenna element (Low-profile Multi-band Antenna Element).

Background technique

With the maturity of the fourth-generation mobile communication technology, people no longer only use mobile communication devices for communication purposes, but also have diversified demands. In order to meet the multi-functional requirements and maintain the light, thin and small characteristics of the communication device, the limited design space in the mobile communication device will be extremely precious. Therefore, how to design a low-profile multi-frequency antenna element for application in future thin mobile communication devices has become a major challenge for antenna designers.

Contents of the invention

The purpose of the present invention is to provide a communication device, which includes a low-profile multi-band antenna element (Low-profile Multi-band Antenna Element). The antenna element has a simple structure, and is particularly suitable for thin tablet computers or thin smart phones.

In a preferred embodiment, the present invention provides a communication device, comprising: a ground element; and an antenna element, comprising a metal portion, wherein the metal portion has multiple bends and substantially forms a loop with a gap structure, the gap is between a first open end and a second open end of the metal part, the metal part extends along an edge of the ground element and does not overlap with the ground element, the antenna element has a a feed-in point, a first part of the metal part is between the feed-in point and the first open end, and a second part of the metal part is between the feed-in point and the second open end; Wherein the feeding point, the first open end, and the second open end all face or are adjacent to the edge of the ground element, and the length of the second part of the metal part is between the first part of the metal part between 0.1 and 0.4 times the length of the

In some embodiments, both the feed-in point and the gap are located at a side of the metal part, and the side faces the edge of the ground element. Under this structure, since the mutual coupling between the multiple line segments of the metal part is not high, the metal part can be narrowed and elongated. Therefore, the overall height of the metal portion on the edge of the ground element can be effectively reduced, thereby achieving a low-profile appearance of the antenna element.

In some embodiments, the metal portion is adjacent to a corner of the ground element and extends along two adjacent edges of the corner. Under this structure, the antenna element will have two resonant current components that are approximately perpendicular to each other, and the vertical and horizontal radiation fields of the antenna element are approximately equal. Therefore, the antenna element can easily receive and transmit vertically and horizontally polarized electromagnetic waves, and is suitable for more complex mobile communication receiving and transmitting environments.

In some embodiments, when the antenna element is adjacent to the corner of the ground element, the feeding point and the gap are respectively adjacent to the adjacent edges of the corner. The present invention can make full use of a clear space in the corner of the communication device to design the antenna element, so as to obtain better impedance matching and radiation efficiency.

In some embodiments, the metal part is approximately a hollow L-shape. In some embodiments, the metal portion is approximately a hollow strip. In some embodiments, the ground element and the antenna element are disposed on a dielectric substrate. In some embodiments, the dielectric substrate is a FR4 (Flame Retardant4) substrate. In some embodiments, a signal source is also coupled to the feed point of the antenna element via a feed matching circuit. In some embodiments, the feed-in matching circuit includes a first capacitor, a second capacitor, and an inductor, the first capacitor is coupled between the signal source and the feed-in point, and the inductor is coupled between the feeding point and a ground potential, and the second capacitor is coupled between the feeding point and the ground potential.

In some embodiments, the antenna element operates in a first frequency band and a second frequency band, wherein the frequency of the first frequency band is lower than the frequency of the second frequency band. In some embodiments, the first frequency band is approximately between 704 MHz and 960 MHz, and the second frequency band is approximately between 1710 MHz and 2690 MHz. The first part of the metal part can excite a first resonant mode in the first frequency band, and the second part of the metal part can excite a second resonant mode in the second frequency band. Since the length of the second portion is between 0.1 and 0.4 times the length of the first portion, the first portion can also excite another high-order resonance mode within the second frequency band. The high-order resonant mode is combined with the second resonant mode of the second portion to form a wide frequency band, so that the antenna element can cover multiple frequency bands. It is worth noting that since the second part is adjacent to the first part, mutual coupling will occur between the two, so that the length of the second part is only about 0.17 times the wavelength of a center frequency of the second frequency band, which is obviously 0.25 times lower than the generally required wavelength. In some embodiments, the antenna element is substantially a planar structure. In some embodiments, the length of the antenna element is only about 60 mm, and the height of the antenna element is only about 6.5 mm.

The communication device of the present invention can achieve a low profile appearance of the antenna element.

Description of drawings

FIG. 1 is a schematic diagram showing a communication device according to a first embodiment of the present invention;

2 is a diagram showing return loss of antenna elements of the communication device according to the first embodiment of the present invention;

3 is an antenna efficiency diagram showing antenna elements of the communication device according to the first embodiment of the present invention;

4 is a schematic diagram showing a communication device according to a second embodiment of the present invention; and

FIG. 5 is a schematic diagram showing a feed-in matching circuit according to an embodiment of the invention.

Wherein, the reference signs are explained as follows:

100, 400～communication device;

10, 40 ~ grounding element;

101, 102, 401 ~ the edge of the grounding element;

11, 41～antenna element;

12, 42～Metal Department;

121, 421～the first open end of the metal part;

122, 422～the second open end of the metal part;

123, 423～the feeding point of the antenna element;

124, 424～The first part of the metal department;

125, 425 ~ the second part of the metal part;

129, 429～the hollow part of the metal part;

13, 43 ~ clearance;

14 ~ signal source;

211～the first frequency band;

212 to the second frequency band;

31, 32～antenna efficiency curve;

510～feed into the matching circuit;

C1～the first capacitor;

C2～the second capacitor;

L1～inductor;

VSS ~ ground potential.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific embodiments of the present invention are listed below and described in detail in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram showing a communication device 100 according to a first embodiment of the present invention. The communication device 100 can be a smart phone (Smart phone), a tablet computer (Tablet Computer), or a notebook computer (Notebook Computer). As shown in FIG. 1 , the communication device 100 includes at least a ground element 10 and an antenna element 11 . The grounding element 10 can be a metal plane laid on a dielectric substrate (not shown), such as an FR4 (Flame Retardant4) substrate or a system circuit board. The antenna element 11 includes a metal portion 12 . The metal portion 12 has multiple bends and roughly forms a loop structure with a gap 13 . More specifically, the metal part 12 has a first open end (Open End) 121 and a second open end 122, and the gap 13 of the ring structure is between the first open end 121 and a second open end 122 between. The metal portion 12 extends along two adjacent edges 101 , 102 of the ground element 10 and does not overlap with the ground element 10 . In some embodiments, the metal portion 12 is approximately a hollow L-shape, and a hollow portion 129 of the metal portion 12 is approximately a smaller L-shape. The antenna element 11 has a feed point 123 coupled to a signal source 14 . The metal part 12 includes a first portion 124 and a second portion 125 . The first portion 124 of the metal part 12 is located between the feed point 123 and the first open end 121 , and the second portion 125 of the metal part 12 is located between the feed point 123 and the second open end 122 . The feeding point 123 , the first open end 121 , and the second open end 122 are all facing or adjacent to the adjacent edges 101 , 102 of the ground element 10 . The length of the second portion 125 of the metal portion 12 is between 0.1 and 0.4 times the length of the first portion 124 of the metal portion 12 . The antenna element 11 can be regarded as a dual branch antenna, wherein the first portion 124 of the metal portion 12 is a long branch, and the second portion 125 of the metal portion 12 is a short branch. The long branch can be used to excite a low frequency band and the short branch can be used to excite a high frequency band. In some embodiments, the metal portion 12 is adjacent to a corner of the ground element 10 and extends along the two adjacent edges 101 , 102 of the corner. In some embodiments, the feeding point 123 and the gap 13 are respectively adjacent to the two adjacent edges 101 , 102 of the corner. It should be noted that the communication device 100 may also include other components, such as a touch panel, a processor, a speaker, a battery, and a casing (not shown).

FIG. 2 is a graph showing the return loss (Return Loss) of the antenna element 11 of the communication device 100 according to the first embodiment of the present invention. In some embodiments, the element dimensions and element parameters of the present invention may be as follows. The area of the ground element 10 is about 200x150mm ² . The antenna element 11 is a low profile planar structure. The dimensions of the antenna element 11 are approximately 60x6.5 mm ² . The ground element 10 and the antenna element 11 are disposed on a dielectric substrate. The dielectric substrate may be an FR4 (Flame Retardant4) substrate with a thickness of 0.8 mm. The width of the gap 13 of the ring structure is about 1 mm to 2 mm. The length of the first portion 124 of the metal part 12 is about 105 mm. The length of the second portion 125 of the metal part 12 is about 21 mm. As shown in FIG. 2 , the antenna element 11 operates in a first frequency band 211 and a second frequency band 212 . In some embodiments, the first frequency band 211 may cover the LTE700/GSM850/900 frequency band (approximately between 704MHz and 960MHz), and the second frequency band 212 may cover the GSM1800/1900/UMTS/LTE2300/2500 frequency band (approximately between between 1710MHz and 2690MHz).

FIG. 3 is a graph showing the antenna efficiency (Antenna Efficiency) of the antenna element 11 of the communication device 100 according to the first embodiment of the present invention. The antenna efficiency curve 31 represents the antenna efficiency (including return loss) of the antenna element 11 in the LTE700/GSM850/900 frequency band (approximately between 704MHz and 960MHz), and the antenna efficiency curve 32 represents the antenna element 11 in the GSM1800/1900/UMTS / Antenna efficiency (including return loss) in the LTE2300/2500 bands (approximately between 1710MHz and 2690MHz). As shown in FIG. 3, the antenna efficiency of the antenna element 11 in the LTE700/GSM850/900 frequency band is about 50% to 70%, and the antenna efficiency in the GSM1800/1900/UMTS/LTE2300/2500 frequency band is about 55%. % to 85%, which can meet the actual application requirements.

FIG. 4 is a schematic diagram showing a communication device 400 according to a second embodiment of the present invention. In the communication device 400 of the second embodiment, a metal portion 42 of an antenna element 41 only extends along an edge 401 of a ground element 40 . A feeding point 423 and a gap 43 of the antenna element 41 are located on one side of the metal part 42 , and the side is facing the edge 401 of the ground element 40 . The metal portion 42 is roughly a hollow strip, and a hollow portion 429 of the metal portion 42 is roughly a smaller strip. The remaining features of the second embodiment are similar to those of the first embodiment, so both embodiments can achieve similar operational effects.

FIG. 5 is a schematic diagram showing a feed-in matching circuit 510 according to an embodiment of the invention. As shown in FIG. 5 , the signal source 14 can also be coupled to the antenna element 11 of the first embodiment or the antenna element 41 of the second embodiment via a feed-in matching circuit 510 . The feeding matching circuit 510 includes a first capacitor C1, a second capacitor C2, and an inductor L1. The first capacitor C1 is coupled between the signal source 14 and the feeding point 123 (or 423 ). The inductor L1 is coupled between the feeding point 123 (or 423 ) and a ground potential VSS. The ground potential VSS can be provided by the ground element 10 (or 40 ). The second capacitor C2 is coupled between the feeding point 123 (or 423 ) and the ground potential VSS. In the embodiment of FIG. 5, the first capacitor C1 and the inductor L1 form a high-pass matching circuit for adjusting the impedance matching of the antenna element in the first frequency band 211, and the second capacitor C2 forms a low-pass matching circuit for use in To adjust the impedance matching of the antenna element in the second frequency band 212 . It should be understood that the feed-in matching circuit 510 is an optional component and can also be removed in other embodiments.

The device size, device shape, and frequency range mentioned above are not limitations of the present invention. Antenna designers can adjust these settings according to different needs.

The ordinal numbers in this specification and claims, such as "first", "second", "third", etc., have no sequential relationship with each other, and are only used to mark and distinguish two terms with the same name. of different components.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Any person skilled in the art may make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore The protection scope of the present invention should be determined by the appended claims.

Claims (10)

1. A communication device, comprising: a grounding element; and An antenna element, comprising a metal part, wherein the metal part has multiple bends and roughly forms a loop structure with a gap between a first open end and a second open end of the metal part Between, the metal part extends along an edge of the ground element and does not overlap with the ground element, the antenna element has a feeding point, a first part of the metal part is between the feeding point and the first opening ends, and a second portion of the metal part is between the feed-in point and the second open end; Wherein the feeding point, the first open end, and the second open end all face or are adjacent to the edge of the ground element, and the length of the second part of the metal part is between the first part of the metal part between 0.1 and 0.4 times the length of the 2 . The communication device as claimed in claim 1 , wherein both the feeding point and the gap are located at one side of the metal part, and the side is facing the edge of the grounding element. 3. The communication device of claim 1, wherein the metal portion is adjacent to a corner of the ground element and extends along two adjacent edges of the corner. 4. The communication device of claim 3, wherein the feeding point and the gap are respectively adjacent to the adjacent edges of the corner. 5. The communication device according to claim 1, wherein the antenna element operates in a first frequency band and a second frequency band, the frequency of the first frequency band is lower than the frequency of the second frequency band, the first part of the metal part A first resonant mode within the first frequency band is excited, and a second resonant mode within the second frequency band is excited by the second portion of the metal part. 6. The communication device as claimed in claim 5, wherein the first frequency band is approximately between 704 MHz to 960 MHz, and the second frequency band is approximately between 1710 MHz to 2690 MHz. 7. The communication device as claimed in claim 1, wherein the metal part is substantially a hollow L-shape. 8. The communication device as claimed in claim 1, wherein the metal portion is substantially a hollow strip. 9. The communication device of claim 1, wherein a signal source is further coupled to the feed point of the antenna element via a feed matching circuit. 10. The communication device according to claim 9, wherein the feed-in matching circuit comprises a first capacitor, a second capacitor, and an inductor, and the first capacitor is coupled between the signal source and the feed-in point , the inductor is coupled between the feeding point and a ground potential, and the second capacitor is coupled between the feeding point and the ground potential.